Mars Rover:
Astronomy Activities
Using LEGO® Robotics
Grades 6-8
© 2013 Technically Learning
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of their gender, race or socio-economic background, should have the opportunity to pursue a career in
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Special Thanks to:
Tufts Center for Engineering Education and Outreach
Susan Evans
Stephanie Gonzalez
Rebecca Reilly
Kelly Weston
Cover photo courtesy of NASA/JPL-Caltech.
Page 2 of 104
Mars Rover Guide Overview:
The Mars Rover Unit is comprised of a series of hands-on activities that are divided into three units. In Unit One,
students explore gravity, friction and the concept of autonomous robots by building a vehicle that rolls down a
ramp, learning about LEGO® MINDSTORMS® programming, creating a robot that is controlled remotely and
designing a robot that drives forward autonomously. In Unit Two, students learn about the environment on Mars
as they build and design robots that simulate exploring the craters of Mars, function based on the light available on
Mars and search for water on Mars. In Unit Three, students will synthesize all that they have learned in the prior
two units to build a rover that navigates through an obstacle course. Each unit is designed to meet state and
national standards in math and science, with each section offering detailed connections to these standards.
Included are ten activities designed to introduce students to the fundamentals of building and programming LEGO®
Robotics in order to further investigate through technological design. Students will be able to build wheeled rover
robots as well as program looped behaviors that respond to sensors. Furthermore, the extension activities will
encourage students to make cross curricular connections in social studies, language arts, and math by exploring the
NASA Mars missions, experiment in navigating Mars terrain and contemplating what it would take to survive in the
Mars environment.
The lessons of this unit can be used in isolation, or as a group.
Grade level: 6-8
Group size: 2-4
LEGO® Materials needed: LEGO® MINDSTORMS® NXT 2.0 Set with corresponding MINDSTORMS® software
Table of Contents:
Unit One
Page 6
Overview
7
State and National Standards
10
Activity #1: Intro to Mars Rover: Descending Into a Crater
18
Activity #2: NXT Programming Demonstration [Instructor Led]
29
Activity #3: Remote-Controlled Rover
37
Activity #4: Drive Forward
Unit Two
Page 44
Overview
45
State and National Standards
47
Activity #5: Avoid Martian Rocks
Page 3 of 104
54
Activity #6: Explore Mars
61
Activity #7: Power Down at Night
68
Activity #8: Don’t Fall Into Craters
75
Activity #9: Crater Rim Exploration
82
Activity #10: Finding Water on Mars
Unit Three
Page 89
Overview
89
State and National Standards
91
Activity #11: Mars Rover Race
Appendix
Page 98
Glossary of Terms
Page 4 of 104
How to Use This Guide
Activities are broken into three units; within the units or within the guide, activities may be performed
independently of one another. However, many activities build on the skills sets practiced in earlier sections. The list
of state and national standard at the beginning of each unit illustrates how the activities align with established
guidelines. In each lesson, “classroom instructional strategies” outline how best to lead the class through the main
activity of the lesson. You may incorporate the “optional activities” into the main activities to increase the
assignment's complexity, introduce them at the end of the assignment to extend the learning experience, or pose
them as challenges to groups who finish early while other groups finish the main activity.
Included with each activity are worksheets that prompt reflection and observation during and after each exercise.
You should distribute worksheets prior to beginning each assignment, as students may make notes and answer
questions during their experiments. You may also assign some of the questions as an in-class, post-activity exercises
or as homework.
Classroom instructional strategies guide you step-by-step through the activities. The columns on the left give you
critical information about each activity, such as the materials needed or informative background information. These
columns also provide pedagogical and practical tips for facilitating several groups simultaneously and
troubleshooting solutions for building and programming problems students may encounter. Activities can be posed
as challenges to groups, who must figure out the design of the robot and the code to go with it. Additionally, we
have included possible responses to post-activity discussion questions in italics. Finally, the “for further discussion”
sections at the end of each assignment focus on issues raised in the lesson. Teachers may incorporate these topics
into post-activity discussions or future lessons.
Activities have been designed to take an hour, but teachers may want to expand this time for further student
exploration or the optional activities. Here is an example breakdown for an hour-long activity:




Introduction and Engagement: 15 minutes
Designing and Building: 15 minutes
Testing and Improving the Rover: 15-20 minutes
Observations and Conclusions: 10-15 minutes
Teamwork and cooperation are essential for completing the activities in this guide, and the experience students
gain by working in groups is indispensable for today’s world. Here are suggested roles for groups of four students,
which can be assigned by the teacher or decided among the group members. Let students rotate through all the
roles in different activities. Let them reflect on which role they like the best. While it is helpful in some situations to
assign roles so that all have a chance to participate, some classes may find such roles too rigid or unnecessary.
 Designer: While the group brainstorms, the designer sketches what the rover will look like and troubleshoots
mechanical problems.
 Builder: Other group members search for appropriate pieces in the kit while the builder actually constructs the
rover and troubleshoots mechanical problems.
 Code-writer: This student writes down the code that the group will program the robot with and troubleshoots
programming issues.
 Programmer: With group members double-checking and providing support, the programmer sits at the
computer to digitalize the code that the code-writer provides and troubleshoots programming issues.
Page 5 of 104
Mars Rover Unit One Overview:
Unit One is divided into four lessons that will focus on introducing students to LEGO® NXT programming and
building basic rover models through the following activities. In the first activity, students will explore forces and
motion by using gravity to propel a LEGO® rover. In the second activity, students will learn how to program a NXT
“brick” (hard drive). In the third activity, students will use methods of scientific inquiry to design and build a touchsensitive rover, and will use the results of their trials to modify and improve the design of their rover. In the fourth
activity, students will further explore science and technology and improving technical design by programming a
rover to move autonomously.
The lessons of this unit can be used in isolation, or as a group.
Grade level: 6-8
Group size: 2-4
LEGO® Materials needed: LEGO® MINDSTORMS® NXT 2.0 Set with corresponding MINDSTORMS® software
Contents:
Page 10
Activity #1: Intro to Mars Rover: Descending Into a Crater
18
Activity #2: NXT Programming Demonstration [Instructor Led]
29
Activity #3: Remote-Controlled Rover
37
Activity #4: Drive Forward
Learning Objectives for All Lessons:
 Working in groups, students will design and build their own rover and will compare designs to determine which
model is fastest, which travels furthest and which travels most accurately (straight lines).
 Students will run several trials and collect data to accurately assess the validity of their design.
 Students will understand that gravity, friction and inertia affect speed and distance travelled.
 Through repeated trials, students will understand average speed.
 Students will understand the basics of NXT programming, which allows the technological instrument (the
“brick”) to respond to external stimuli and complete students’ designs.
 Students will distinguish between autonomous and dependent technological designs and will recognize the
superiority of autonomous designs for space technologies.
 Students will successfully build a rover and will theorize about modifications to improve this design.
 Students will design and build their own rover. While students may begin from the model proposed in this
guide, they should be encouraged to engineer improvements.
Page 6 of 104
Educational Standards Addressed:
National Standards: Science
NS.5-8.1 SCIENCE AS INQUIRY
As a result of activities in grades 5-8, all students should develop:
 Abilities necessary to do scientific inquiry
 Understanding about scientific inquiry
NS.5-8.2 PHYSICAL SCIENCE STANDARDS
As a result of their activities in grades 5-8, all students should develop an understanding of:
 Motions and Forces
NS.5-8.4 EARTH AND SPACE SCIENCE STANDARDS
As a result of their activities in grades 5-8, all students should develop an understanding of:
 Earth in the solar system
NS.5-8.5 SCIENCE AND TECHNOLOGY STANDARDS
As a result of their activities in grades 5-8, all students should develop:
 Abilities of technological design
 Understanding of science and technology
Washington State Standards: Science
6-8 INQ SCIENCE AS INQUIRY
As a result of activities, students will learn that:
 6-8 INQC Collecting, analyzing, and displaying data are essential aspects of all investigations.
 6-8 INQE Models are used to represent objects, events, systems, and processes. Models can be used to test
hypotheses and better understand phenomena, but they have limitations.
 6-8 INQF It is important to distinguish between the results of a particular investigation and general conclusions
drawn from these results.
Page 7 of 104
6-8 APP SCIENCE, TECHNOLOGY AND PROBLEM SOLVING
As a result of activities, students will learn that:
 6-8 APPD The process of technological design begins by defining a problem and identifying criteria for a
successful solution, followed by research to better understand the problem and brainstorming to arrive at
potential solutions.
 6-8 APPE Scientists and engineers often work together to generate creative solutions to problems and decide
which ones are most promising.
 6-8 APPF Solutions must be tested to determine whether or not they will solve the problem. Results are used
to modify the design, and the best solution must be communicated persuasively.
6-8 PS1 FORCE AND MOTION
As a result of activities, students will learn that:




6-8 PS1A Average speed is defined as the distance traveled in a given period of time.
6-8 PS1B Friction is a force that acts to slow or stop the motion of object.
6-8 PS1C Unbalanced forces will cause changes in the speed or direction of an object's motion.
6-8 PS1D The same unbalanced force will change the motion of an object with more mass more slowly than an
object with less mass.
6-8 ES1 EARTH AND SPACE SCIENCE
As a result of activities, students will learn that:
 6-8 ES1B Earth is the third planet from the sun in a system that includes the Moon, the Sun, seven other major
planets and their moons, and smaller objects such as asteroids, plutoids, and comets. These bodies differ in
many characteristics (e.g., size, composition, relative position).
Page 8 of 104
Mars Rover Robotics Curriculum Guide Pre-Test
Name:
Please circle one:
Girl
Boy
1. Which statement best describes your feelings about science:
a) I like science class, but I like other subjects more
b) Science is difficult for me but I like science class
c) I go to science class because I have to
d) I love science class!
e) I like doing science, but I prefer it outside of class
2. What is your favorite part of science class?
3. Which statement best describes your feelings about careers in the science, technology, engineering,
or mathematics fields:
a) I like one or more of these fields, but I don’t know a lot about careers in those fields
b) I’m not interested in getting a career in those fields
c) I imagine myself pursuing a career in one or more of those fields
d) I like those fields, but I’m unsure if I want a career in them
4. After you graduate from High School, what kind of training or career do you plan to pursue?
5. What do you think robots can do to improve daily life?
Page 9 of 104
Activity #1: Intro to Mars Rover:
Descending into a Crater
In this hands-on activity, students will investigate gravity and propulsion (forces and motion) on both Earth and on
Mars. This activity will introduce students to the fundamentals of building and programming LEGO® Robotics in
order to further investigate technological design. Students will encounter iterative design, fair trials, and data
assessment “best practices.”
Learning Goals
Washington State EALRs Addressed in this Activity
Working in groups, students will design and build
their own rover and will compare designs to
determine which model is fastest, which travels
furthest and which travels most accurately (straight
lines).
6-8 APPD The process of technological design begins by
defining a problem and identifying criteria for a successful
solution, followed by research to better understand the
problem and brainstorming to arrive at potential solutions.
6-8 APPE Scientists and engineers often work together to
generate creative solutions to problems and decide which
ones are most promising.
6-8 APPF Solutions must be tested to determine whether or
not they will solve the problem. Results are used to modify
the design, and the best solution must be communicated
persuasively.
6-8 INQC —Investigate— Collecting, analyzing, and
displaying data are essential aspects of all investigations.
Students will run several trials and collect data to
accurately assess the validity of their design.
Students will understand that gravity, friction and
inertia affect speed and distance travelled.
Through repeated trials, students will understand
average speed.
6-8 PS1B Friction is a force that acts to slow or stop the
motion of objects.
6-8 PS1C Unbalanced forces will cause changes in the speed
or direction of an object's motion.
6-8 PS1D The same unbalanced force will change the motion
of an object with more mass more slowly than an object
with less mass.
6-8 PS1A Average speed is defined as the distance traveled
in a given period of time.
Page 10 of 104
Reviewing Prior
Knowledge
In prior grades students:
 Learned to work
individually and
collaboratively to
produce a product of
their own design.
 Learned to use basic
tools to measure
force, time, and
distance.
 Learned to plan
investigations to
match a given
research question.
Vocabulary






Gravity
Propulsion
Inertia
Force
Friction
Crater
Materials
 Ramp
 LEGO® NXT kits (1
per group of 2-4
students)
 Worksheets
(included in this
guide)
 Stopwatches
 Rulers/Measuring
Tape
 (Optional)
Sandpaper
Before the Activity:
Teacher Preparations:
Build a gentle-incline ramp. Cardboard pieces taped together work well, but make
sure the seam is level or not the place at which students will propel their vehicles
down the ramp. The ramp only needs to be 6 or 8 inches tall. Make the ramp shorter
if you don’t have much room for the rovers to roll.
Mark the ramp with a horizontal black line near the top to indicate the “fair” starting
point for all vehicles. Mark the ramp with a straight vertical line down the center to
indicate the “ideal” trajectory of vehicles down the ramp. This latter line will be
useful for measuring deviation from the center line for students’ vehicles.
Resources for Educators:
Video: “Opportunity Poised to Enter Victoria Crater”
Link: http://bit.ly/dnHF41
This video is a good introduction from NASA to the Rover, crater exploration,
“roadblocks” to getting to Victoria Crater and challenges to traversing Mars’ terrain.
It would be an apt video to show in class to introduce Mars Rover activities.
Interactive Website: “Mars Exploration Rovers”
Link: http://bit.ly/9GcswH
This link will familiarize students and instructors with the components of the Mars
Rover.
Video: “Testing the Rovers for Treacherous Mars Terrain”
Link: http://bit.ly/9J73ei
This video shows NASA engineers determining the limits of the rovers. They build a
ramp and see how steep of an incline the rovers can ride over.
Fun Resources for Students:
Interactive Website: “Return to Mars: Your Weight on Mars”
Link: http://bit.ly/XfhQRo
Interactive Website: “Anatomy of a Rover”
Link: http://to.pbs.org/d3SVTZ
Online Photo Gallery: “Mars Science Laboratory”
Link: http://bit.ly/a2EFPw
Page 11 of 104
Vocabulary:
Engagement Activities
Gravity is another main
theme for this activity.
Gravity helps keep us on
the ground, causes a ball
to fall and makes home
runs difficult to hit.
Friction slows things down and tries to pull them to a stop. Friction is what helps us
stop after sprinting down the sidewalk and lets us turn our bike or car around a
corner. Friction also helps kites fly and parachuters fall slowly. Use this activity to get
kids moving and thinking about friction.
Remember that mass is
the amount of matter, or
stuff, an object contains.
Weight is the
measurement of the pull
of gravity against that
object. Since the moon
has less gravity than the
Earth, something won’t
have the same weight
here as it does on the
Moon, but it will have
the same Mass.
1. Clear a sufficiently long space of your classroom for students to “race” next to
each other.
2. Select at least four students to have the first race. Two should be wearing
sneaker and two should have just their socks on. Tell students that they are not
allowed to pick up their feet during the race. They must slide along the floor.
3. Have the same students race again but switching the sneakers and socks roles.
Repeat races as many times as necessary.
NOTE: If you don’t want your students removing their shoes, this activity can be
performed with all students wearing their shoes but racing on different floor surfaces,
such as tile, carpet, grass, asphalt, etc.
 Was it easier to race with or without your shoes on? Why?
 What type of surface were you racing on? Did that affect the friction against
your socks or sneakers?
 Based on your experience in this activity, what kind of tires would you design
for a car? What kinds of surfaces are difficult for cars to drive on?
Page 12 of 104
Activity Preparation
Tips:
Copy the worksheet for
this activity and
distribute it before the
activity begins. Students
can make notes about
their vehicles’
performance on these
and can answer
questions that will better
prepare them to
participate in class
discussions. Questions 34 can be saved for
homework if class time
does not permit
completion of the
worksheets in class.
Classroom Instructional Strategies
Building the Rover
Students will have much freedom building their rovers; they can use any of the
pieces in the LEGO® NXT robotics kits. Note: this may also feel like a limitation to
some of the students, who would like different or more pieces; encourage them to
use their imaginations and use available parts to approximate pieces they need.
Students’ rovers must do the following:




Pass the drop test: vehicle must survive a “fall” of 4-5 inches.
Pass the drive test: vehicle must maintain integrity as they roll one foot.
Have three or more wheels.
Be situated above the ground—no dragging.
Sample versions of basic vehicle:
Construction Tips:
 Show students
sample versions of
basic vehicles, but
assure them there is
no “right” design.
 Make sure that the
students build a
vehicle of some sort.
While a single wheel
rolled down the
ramp could win, in
theory, that won’t
help them develop
building and
engineering skills.
 The NXT is not
required since there
is no need to power
the rover. The extra
weight won’t make
the rover roll more
or less, even if you
add it.
Page 13 of 104
Troubleshooting Tips:
Building a simple
vehicle can be
surprisingly difficult.
Although later activities
will use the motors in
the construction of the
rovers, they are not
needed in this activity
and will actually cause
the rover to slow down.
Problem: Students have
a difficult time
constructing a sturdy
base to hold the
wheels.
Solution: Attachments
need to have two
connection points so
they cannot freely
rotate.
Problem: Wheels are
not able to spin freely,
or the axle slides back
and forth.
Solution: Use a bar
(with a cross-shaped
cross-section) as the
axle, which will be fixed
to the wheels. The axle
needs to be held in
place so that it can spin
freely, but also so that it
doesn’t slide back and
forth. Use small spacers
on both sides of the
rover to keep the axle in
place and to prevent
the wheels from
rubbing on the side of
the rover.
Testing the Vehicle
Step 1: Roll cars down the inclined plane from the center point. Time how long it
takes once the car exits the ramp until it stops moving.
Step 2: Measure distance from the end of the ramp to where the car stopped, and
then from the center line of the ramp to the car’s stopping position.
Step 3: Repeat trial for each car in the competition, documenting each car’s time
and distance travelled from the end of the ramp and from the center line.
Page 14 of 104
Science as Inquiry:
Scientists and engineers in
nearly every field—from
doctors to astronomers,
computer programmers,
and building engineers—
approach problems in a
similar manner. First, they
see a problem to be fixed
or a need to be filled. They
will then do some research
to see if anyone else has
fixed this problem before,
and if no one has solved
this problem, they will
brainstorm to see how to
approach this unique
circumstance. From their
brainstorm, they choose
the best approach and
then plan what needs to
be done to create the
solution. This includes
deciding on materials,
schedules, and an order in
which the plan should be
completed. They then
create the program,
equipment or experiment
that might yield answers.
They test it, collect data
(information), and
determine if their
equipment or experiment
produced a solution to the
initial problem. Most
scientists will then
redesign and retest their
original plan. They will
then make observations
and conclusions about
their trials and
experiements.
Step 4: Discuss the trial with the observation questions below. Once students have
consulted on what makes these basic cars successful, give them 5-10 minutes to
rework their original designs.
Step 5: Rerun Steps 1-3, noting which cars were more successful than in the previous
trials. Success can be measured by distance travelled, accuracy (how close the car
adhered to the “middle of the road”), speed or some combination of these factors.
Discussion and Observations
 Do the rovers roll further when released higher up the ramp? Why? Yes. The
rover has longer on the ramp to gain more speed. Put in another way, gravity
has more distance to pull the rover down.
 How would your rover be affected by the weaker gravity on Mars? Since the
gravity on Mars is weaker than on Earth, the rover builds up less speed and
would travel slower on Mars.
 How would your rover be affected if it were on different surfaces, such as the
dust and sand on Mars? The loose dust and sand causes more friction, which
slows the rover down more than a smooth hard surface. See “Extension
Activities” for ways in which you can demonstrate this to the class.
 Why were the distances different from run to run for the same rover? When
distances differ from run to run, how can we determine how successful our
rovers are in distance, accuracy and speed? Many factors that affect the
distance can change slightly from run to run: air currents, how it is released, dust
bunnies, etc. Averaging the results allows us to best determine how well a vehicle
performs, and to predict future behaviors.
 Compare the rovers’ average distances across the five runs. Are there any
patterns for what types of rovers go the furthest? Rovers with bigger wheels
often tend to go a little further, although vehicle shape and construction can
influence this. Ask students to speculate on what might have made these vehicles
travel the furthest or the most accurately. Then, ask them how they would test
these hypotheses. Note: the weight of the rovers will not influence the distance
travelled, but will affect initial speed as vehicles overcome initial moment of
inertia.
In this activity and
throughout this guide,
students will be solving
problems as scientists and
engineers do every day.
Page 15 of 104
Optional Activity Variations
Testing Friction
Let the rover roll down the ramp five times with rubber treads on your wheels. Then do five runs with no rubber on
the wheels (just the hard plastic hub). Record the distance that the rover travels for each run. Average the distances
for the rubber wheels and the non-rubber wheels.
 Which type of wheel rolls further? Why? The wheels without rubber should roll slightly further. The rubber
wheels produce slightly more friction because the rubber slightly deforms at the point touching the ground. This
extra friction causes the rubber wheeled rover to slow down and stop sooner than the non-rubber wheeled
rover.
 What happens if we attach something to the back of vehicle and roll it down the ramp or along the ground?
Dragging something behind the rover will slow it down because it is a balancing force to gravity or to the
forward motion of the vehicle.
 What happens if we roll the rover over different types of surfaces (smooth, rough)? Repeat this activity on
different surfaces, such as on top of cardboard, on carpet, linoleum, or pavement outside. Take sandpaper
(“optional” on the materials list), cover the top of the ramp and roll a vehicle down the ramp. Use the vehicle’s
slow progress to demonstrate how friction acts as a force that slows down the vehicle – a balancing force to
gravity, which is trying to pull the vehicle down the ramp.
Adding Mass
 How do adding heavy pieces (such as the NXT) change the speed of the vehicle as it goes down the ramp?
Students will have to test out the effects of adding mass to their car to determine if their vehicle goes faster,
slower, or stays the same. Reasons that might change the car’s speed include: friction of the axles rotating in
LEGO® beams, the subtle interaction between the wheels and the surface it’s rolling on, or air resistance may
come into play if your ramp is tall enough.
For Further Discussion
Mass vs. Weight
Mass and weight are two different measures which are often confused because as long as you stay on one planet
(like Earth) they are the same.
Mass is the amount of “stuff” in an object, whereas weight is how much gravity pulls down on that stuff. For
example, if you go to the moon, you don’t change size, or lose or gain substance; yet you weigh less because the
moon is smaller than the earth and therefore has lower gravity (it pulls down on you less).
Page 16 of 104
Name: __________________________
Descending Into a Crater
Today you will be competing in a Mars Rover competition. The challenge is to design an un-powered rover that
rolls the farthest after coasting down the side of a Martian crater.
Please answer the questions below before building your rover.
1.
What is gravity? How will it help your rover to move?
2.
Draw a picture of what you plan to build. Label as many parts as possible with the correct names of the
pieces you plan to use. Note: This drawing is only a draft; feel free to change your design as you build.
Build your rover! Make sure to test it out on the ramp. Record the results of your five official runs below. Be
sure to include units.
Run #
1
2
3
4
Distance from ramp
Distance from center line
Time
After completing your runs, answer the following questions:
3.
Calculate the average speed of your car. Remember: Speed = Distance ÷ Time
4.
Was there a certain type of car that went farther than others? Explain.
5.
How would your rover be affected by the weaker gravity on Mars? Explain in detail!
Page 17 of 104
5
Average
Activity #2:
NXT Program Demonstration [Instructor Led]
In this lesson, instructors will demonstrate how to program the NXT “brick.” This lesson is crucial for students’
understanding of sensors, how the “brick” responds to external stimuli, and how the “brick” can be programmed to
anticipate environmental conditions and stimuli. The material presented in this activity will affect future activities in
this curriculum, and students may need additional practice with the basic programming commands; shorter
versions of this activity can be used as refreshers for students prior to beginning other NXT-based activities.
Remind students to keep the worksheet from this lesson available when completing the other activities in this
guide. The worksheet will serve as a summary of all the icons students can use while they design their own code in
later activities.
Learning Goals
Students will understand the basics of NXT
programming, which allows the technological
instrument (the “brick”) to respond to external
stimuli and complete students’ designs.
Washington State EALRs Addressed in this Activity
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better
instruments and suggesting ideas for new designs.
Technology drives science by providing instruments and
research methods.
Page 18 of 104
Reviewing Prior
Knowledge
In prior grades
students:
 Learned to work
individually and
collaboratively to
produce a product
of their own
design.
 Learned to plan
investigations to
match a given
research question.
Before the Activity:
Teacher Preparations:
Teachers should group 2-4 students per kit prior to beginning the activity. While
students will not be constructing as a group in this activity, instructors will find it
useful to help students connect sensors and motors to their NXT Bricks. To minimize
distractions, only set out the brick, the connecting wires, motors and sensors.
For the purpose of this activity, the teacher should reserve one kit for demonstration
purposes. Ideally, the instructor will set up an overhead projector connected to a
classroom computer; here, the instructor will project the NXT program for the whole
class to see and will lead the class discussion.
Make sure the NXT program has been loaded onto the instructor’s computer before
the class begins.
Vocabulary






NXT
“Brick”
Sensors
Program(ming)
Input
Output
Materials
 LEGO® kits (1 per
group of 2-4
students)
 Worksheets
(included in this
guide)
 Overhead device
(for projecting NXT
program for class
observation)
Resources for Educators:
Article: “The Rover’s Brains”
Link: bit.ly/cnxc61
This article is a good resource for relating Rover’s functions to human functions so
that students can recognize how their bodies – as autonomous beings – are similar to
the programmed Rover.
Video: “Computer Simulation of Autonomous Navigation”
Link: http://bit.ly/16kNEoj
This short video illustrates how the Rover navigates autonomously.
Article: “NASA Mars Rover Getting Smarter as it Gets Older”
Link: http://bit.ly/aep1uX
This article details how Mars Rovers make decisions about navigation autonomously
while on Mars (without having to be reprogrammed repeatedly). This would be a
good article to assign for homework, either before or after this activity.
Fun Resources for Students:
Game: “Can You Get the Rover to the Rock?”
Link: http://bit.ly/aDCv19
Page 19 of 104
Tips and Tricks:
Programming may be a
new concept for your
students. It is helpful
to introduce
“programming” with
some or all of these
engagement activities.
Once the students
have completed the
rest of the lesson, it
can be beneficial to
review programming
again with activities
like these since it is
such an important
concept to LEGO®
robotics.
Learning a
programming language
is like learning any
other new language.
The more you practice,
the easier it becomes.
It’s not expected for
you to master a
programming language
the first time you sit
down to use it. You
wouldn’t expect
someone to become
fluent in Spanish or
Arabic after their first
lesson.
Engagement Activities
1. Programming is all around us. It tells the computers what to do, the soda
machine which soda to give us, our cell phones how to make phone calls, and can
even save lives by making our cars and planes safer. Ask students to brainstorm
other types of programs they are familiar with or other ways computers and
electronic systems may use programming.
2. You can think of programming like a very specific set of instructions that a
computer can carry out. You have to be very, very careful when you instruct a
computer because it can’t think for itself, and it doesn’t “know what you mean.”
Activity: Have students pair up. Have each of the students write instructions to
put on their socks and shoes. When they’re done, have them swap the
instructions and make their partners follow the instructions as closely as they can.
Make sure to follow every instruction to the letter and nothing that is not on the
paper. As the kids see their instructions being misinterpreted, discuss how
important it is to be specific with programming.
3. When we program a computer we also have to speak in a new type of language.
Since the computer doesn’t understand English, we will write our instructions in a
“program” that the computer can understand. In this case, we will be using a
programming language called “NXT.” NXT uses symbols to tell the computer what
to do. As you get more comfortable with the symbols and start thinking like a
programmer, you’ll be able to create more complicated programs and make your
rover do more interesting things.
Activity: This is a version of Simon Says in which students will pretend to be
robots and can only follow commands that are visual rather than spoken. Draw
large shapes (red star, blue square) on pieces of paper and tell students that each
shape indicates a different action: stand up, sit down, raise your hand, etc. Switch
off saying these actions and holding up the signs. Students should only react to
the commands when the signs (visual language) are used and should do nothing
when the auditory commands are used. Ask students if it was hard to only react
to the visual commands. Why? Did it become easier as the game went on to
remember which symbol was which? Ask students if they think they will become
accustomed to the NXT visual programming language with time.
Page 20 of 104
Activity Preparation
Tips:
Copy the worksheet
for this activity and
distribute it after the
demonstration of the
activity. While the
worksheet can be
done in class, it can
also be sent home with
students for
homework and to test
retention of material.
You can either copy
the command guide
appended to this
activity, or you can
project it into a screen
for the class to see.
Students may benefit
from having a paper
copy of the command
guide for future
reference.
Classroom Instructional Strategies
Guided, Hands-On Kit Exploration
This is the time for students to name and learn to recognize parts they did not
encounter in the first activity.
 As you name the brick, have students turn the
bricks on and off. The brick turns on by the
orange button. And pressing the rectangular
dark grey button will prompt you if you’d like to
turn off the brick. Select “Yes” with the orange
button.
 When introducing the motors, have
students turn the orange piece to see the
movement of the motor.
 As you name and show each of the sensors, ask students to identify these
sensors. Ask students what they think each of these sensors measure, and
explain how the sensors make these measurements.
o Light sensor: Distinguishes between
dark and light by using a photodiode,
which outputs a voltage proportional to
the intensity of light.
o Sound sensor: Assesses noise levels by
measuring the fluctuations in air
pressure caused by sound waves.
Page 21 of 104
Student Materials:
At the end of this
curriculum guide,
you’ll find a glossary of
all terms described
here for you or your
students’ reference.
o Touch sensor: Reacts to the orange button
being pressed and released or pressed and held
down. Either the circuit is connected or not
connected.
o Ultrasonic Distance sensor: Measures how far an object is away from the
front of the sensor, which essentially allows your LEGO® robot to “see.” The
sensor works by sending out sound waves that bounce off the object in front
of it and bounce back to the sensor. The
robot knows how fast the ultrasonic
waves travel and the time it took to
travel, so it can calculate the distance of
the object in front of it. This is similar to
echolocation that bats and dolphins use
to navigate. [Ultrasound is a higher
frequency sound than humans can
hear.]
 As you show the cables, have
students practice attaching motors
and sensors to the brick with the
cables.
 The numbered ports are for connecting the
sensors and the lettered ports are for
connecting the motors.
Page 22 of 104
Programming Notes:
NXT Programming Demonstration
A single brick
commands a single
behavior; show how
you can string the
icons together in
linked in a chain to
form more complex
series of behaviors for
your robot.
Explain to students that in order to make a robot, you have to physically build the
robot and also create instructions for what the robot should do (called the program
or code). We will now focus on how to write a program to make the robot behave as
we’d like:
On the NXT brick, the
orange button selects
items and folders, and
the grey rectangular
button returns to the
previous folder level.
 When you open up the MINDSTORMS® software, enter a name for your
program in the box outlined in orange that’s labeled “Start new program” to get
started. Then press Go. You can name your program according to what your
robot will do, the activity name, your team name and date, or whatever system
you’d like to keep track of your files.
 The large gridded space is the canvas where you will create your program. The
square icons on the left side are the building blocks for your program. You’ll line
up different icons in a straight line starting where is says “Start” on the canvas.
The robot will perform the function of each icon from left to right, just like
reading a book.
 NOTE: This activity guide is based off of the common palette of icons, unless
stated otherwise. Make sure that the word “Common” is above the column of
icons. If it says “Complete” or “Custom” above your first icon, you’ll have switch
manually to the common palette by clicking on the green circle below the
column of icons.
Construction Demo:
 Use a cable to hook up a motor to one of the lettered ports on the NXT.
 Attach a wheel to the orange part of the motor with an axle to make the
spinning more visible.
 Write a simple program that turns on the motors for five seconds. Start by
clicking and dragging a "Move" icon (from the "Common" tab of commands on
the left side of the canvas) into the spot on the canvas where it says “Start.”
When your icon is selected (ringed in blue on the canvas), a palette of
adjustable details will appear at the bottom of the screen. To write this
program, you’ll have to select which port you attached your motor to (A, B, or
C), and you’ll have to adjust the duration. Switch the duration units from
“Rotations” to “Seconds.” The code would look like this on the canvas:
Page 23 of 104
Tips:
 If you ever need to
stop your program
while it’s running,
press the grey
rectangular button
on the brick.
 The motors are
always attached to
the lettered ports
and the sensors
are always
attached to the
numbered ports.
 To delete an icon,
click on it so it
becomes
highlighted in blue
on the canvas and
then press
“Backspace.”
 To select more
than one icon at a
time, place your
cursor on the
canvas above or
below your icons
and click and drag
across the icons
you’d like to select
 Use the square orange button on the NXT brick to turn it on, if you have not
done so already. Connect the NXT brick to the computer using the USB cable.
Click the Download button, which is the lower left-hand button in the cluster of
buttons on the bottom right of the screen. (Note: the
button in the center of this cluster is the Download and
Run button. It is better to get into the habit of using
just the Download button because if you have a robot
that drives, the Download and Run button will
immediately start your program, and your robot will
drive away while still connected to the computer.)
 Unplug the USB cable.
 On the NXT brick’s display, select My files using the orange button (This is the
first option when you turn your brick on). Select Software files. Select the name
of your program. The display screen will now say “Run” and when you select that
using the orange button, your program will start running.
Sensor Demo:
 Using the demo you just constructed, use a cable to hook up the ultrasonic
distance sensor to one of the numbered ports.
 Write a simple program that causes the motor to turn for 5 seconds once the
distance sensor senses an object less than 10 inches away. Use same code from
before but insert a Wait Icon before the Move Icon. If you hover your mouse
over the Wait Icon on the left hand side, you’ll see different options to choose
from. Click and drag the furthest on the right (which if you hover your mouse
over is labeled “Distance”) and insert it to the left of the Move Icon. Select the
port you have your sensor attached to and change the “Wait” distance to read
“<10 inches.” The code would look like this:
 Download this program to the NXT and demonstrate that it causes the motor to
turn on and spin the wheel once students the distance sensor senses something
less than 10 inches away. You could do this by running the program and having
nothing within 10 inches of the distance sensor, and then have a student
volunteer place their hand less than 10 inches away from the sensor.
Discussion and Observations
 Have students lead you through how you would build and program a robot that
causes the wheel to spin once it bumps into something.
Page 24 of 104
Optional Activity Variations
This optional activity can be used to extend the original NXT introduction session, or can be used as a refresher for
students who need practice with the basic NXT programming.
Practice with programming
Make sure students have access to a computer; if there are not enough laptops for each group, stagger students’
access to computers by first having some groups work on building their models while other groups write the code,
and then switch the groups.
 How would you build and program a robot that could sense distance and alert you when you were too close
to a wall/other solid object?
For Further Discussion
 To get students thinking about space exploration, ask them if they think we should try to send humans to
Mars?
Some people argue that we should be working to develop technology to be able to send astronauts to Mars
because as NASA astronaut Rex Walheim states, “There have been a lot of clues we’ve seen that there is
potentially life on Mars, but the only way to find out is really to go there.” Check out the full article here:
http://www.huffingtonpost.com/2011/08/17/nasa-astronaut-why-go-to-mars_n_929439.html
Others argue that rovers are adequate for exploratory missions to Mars and cost much less money than sending
humans to Mars. Also, the two or three-year trip to Mars has many risks including “deadly meteoroids, bone
and muscle deterioration, and cosmic radiation” says a NOVA episode from PBS. Check out the article and video
here: http://www.pbs.org/wgbh/nova/space/can-we-make-it-to-mars.html
Page 25 of 104
NXT programming uses icons to represent actions your robot can take.
Common Palette
Move – Activates motors
Record/Play – Records the motors’ movements and then replays them
Sound – Plays sound files or tones
Display – Changes the display on your robot (i.e. shows an image or text)
Wait – Waits for a change in light/sound readings, a distance to an object, or a button push
Loop – Creates indefinite or repeated behaviors
Switch – Chooses from 2 different actions (i.e. do one action if the touch
sensor is pressed in, do a different action if the touch sensor is not pressed)
Each programming icon you select from the menu panel on the left of the screen has many properties you can edit
on the bottom of the screen. These properties are reflected visually on the icon on the canvas. Below is an example
of the adjustable properties for the “Move” icon.
Page 26 of 104
Motors:
 Port: On this “Move” icon, the red arrow is pointing at the letters (C,
B) which indicate which motors will be turning.
 Duration: The purple arrow shows how long the motors will be
turning. In this case the “infinity” symbol is shown because the
motors are set to turn an unlimited amount.
 Power: The blue arrow points to the power level. On this icon, it is
shown at about ¾ power.
 Direction and Steering: The yellow arrow shows the direction the
motors are set to turn. This icon shows that the motors will move
forward.
There are 2 ways to tell the motors to turn the wheels:
 To tell the rover to turn, place a Move icon on the canvas telling just
one of the 2 motors to turn on. This causes the one wheel to rotate
and one wheel to be stationary which results in turning. A slight
variation is to turn one motor going forward, while other motor goes
backwards. This causes the rover to rotate to the right in place.
 Or you can turn on both motors (C and B) and use the steering slider
in the motor properties to tell it to turn. When the slider is in the
middle, the rover will go straight. The more you slide it to one side,
the tighter the rover will turn towards that motor.
Distance Sensor:
 Port: On this “Wait for Distance” icon, the red arrow points to the
port number that the distance sensor is connected to, in this case,
port 1.
 Wait ‘Until’: The blue arrow points to a visual representation of the
distance selected. In this case the slider is show about half full,
indicating that it will wait for an object to be about half of the
distance that the sensor can detect. This is a value of 50 inches.
Light Sensor:
 Port: On this “Wait for Light” icon, the red arrow points to port
number for this sensor.
 Wait ‘Until’: The purple arrow points to a picture of the value of
light the NXT will wait for. In this case, it shows the bars about half
full, indicating that the robot will be waiting for a light level about
halfway between dark and very-bright.
 Function: The purple arrow points to an image indicating that the
light sensor will generate its own light. (This is useful for reflecting
off of nearby surfaces to sense them. See activity 8)
Page 27 of 104
Name: ________________________
NXT Programming
Today we will be learning how to program our NXT rovers. During this session your teacher will be
demonstrating how to write code on the computer and then downloading it from the computer to
the NXT brick.
Complete the activities below:
1.
Draw a line connecting each image with its correct description.
Wait: Waits for a change in light/sound readings, a
distance to an object, or a button push.
Sound: Plays sound files or tones.
Display: Changes the display on your robot (i.e., show
an image or text).
Record/Play: Records the motors’ movements and then
replays them.
Loop: Creates indefinite or repeated behaviors.
Move: Activates motors.
Switch: Chooses from 2 different actions (i.e. do one
action if the touch sensor is pressed in, do a different
action if the touch sensor is not pressed)
2. Describe in detail how you would program the wheels of a car to turn left.
Page 28 of 104
Activity #3:
Remote-Controlled Rover
In this lesson, students will design and build a rover that can be controlled with touch sensors. Students will
demonstrate that they can download multiple programs on their NXT and run different stored programs.
Some student might ask why the rover must be autonomous rather than remotely controlled (like remote
controlled car toys they may have played with.) This lesson provides students with hands-on experience to realize
why rovers on Mars are autonomous rather than remote controlled. From a teacher-provided program, the
students will use the touch sensors to drive the rover first without a delay, as if it is directly remote controlled. Then
the students will use the second provided program to try driving the rover with a delay between command and
response. The students will discover that this makes the rover very difficult to navigate.
Learning Goals
Washington State EALRs Addressed in this Activity
Students will distinguish between autonomous and
dependent technological designs and will recognize
the superiority of autonomous designs for space
technologies.
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 APPD The process of technological design begins by
defining a problem and identifying criteria for a successful
solution, followed by research to better understand the
problem and brainstorming to arrive at potential solutions.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
6-8 APPF Solutions must be tested to determine whether or
not they will solve the problem. Results are used to modify
the design, and the best solution must be communicated
persuasively.
Students will become familiar with programming
code and will theorize about modifications to
improve designs.
Page 29 of 104
Reviewing Prior
Knowledge
In prior grades
students:
 Learned to work
individually and
collaboratively to
produce a product
of their own
design.
 Learned about the
Earth's relationship
to the Sun and
other planets.
Vocabulary
 Autonomous
 Stimulus
 Design
Materials
 LEGO® kits (1 per
group of 2-4
students)
 Worksheets
(included in this
guide)
 Overhead device
(for projecting NXT
program for class
observation)
Before the Activity:
Teacher Preparations:
Using the code laid out in this activity, the instructor should write and save the
code for both time-delayed and non-delayed responses to stimuli. Load the
programs onto an NXT and test that the program works as planned. Right before
the lesson, make sure the NXT program is open on the computer and both remotecontrolled codes are open. Make sure to save these program names as “NonDelay” and “Delay” so that students will be able to download and run the right
program on their NXT.
Resources for Educators:
Article: “Typical Science Instruments”
Link: http://bit.ly/bMQzB8
This article gives details about remote and direct-sensing science instruments used
in space programs.
Article: “X-Band Radio Waves Used By the Rovers to Communicate”
Link: http://bit.ly/9Oa2Re
This article gives information about how the Rover communicates with NASA (and
vice versa).
Fun Resources for Students:
Activity Guide; Instructional Games: “Comparing Earth and Mars”
Link: http://bit.ly/bpXf02
Online Video: “How Does a Remote Control Work?”
Link: http://to.pbs.org/bumY9k
This can be shown after the “For Further Discussion” question at the end of this
activity.
Page 30 of 104
Tips and Tricks:
Engagement Activities
For the first activity, if
space allows, draw
multiple paths on the
floor and split the
students into groups of
four. Two students will
perform the experiment
and two students will
watch and make the
buzzing sound. Have the
students cycle as
appropriate.
Remote Control Students:
The second activity can
be executed with index
cards about different
concepts. Use it to
review concepts of
physics while
experiencing time delay.
Review terms like
gravity, friction, mass
and weight from the
first lesson. Write the
definitions on the cards
and call out the names
of the terms.
Items Needed:
 Chalk or tape
 Blind folds
Clear all the desks from the middle of the room. Draw a path on the floor with tape
or chalk with two lines (like the lines on a road) approximately 50 cm apart. The
path should wind around the room.
1. Have students pair up.
2. Have one student (the rover) stand at the starting line and put on the blindfold.
To reduce the likelihood of later students memorizing the course, spin the
students left and right until they forget the course.
3. Have the other student (the navigator) stand at the side of the path, so he or
she can see the entire path clearly.
4. Using only the commands “move forward”, “turn left” and “turn right” have the
navigator command the rover to move through the path.
5. Have the rest of the class watch. When the rover steps outside of the path,
have the students make a “buzz” sound.
6. Cycle through each pair of students until each student has tried to be both the
navigator and rover.
Time Delay Exercise:
Items needed:
 Two sets of index cards with small pictures of LEGO® robotics parts (the brick,
wheels, sensors, etc.)
Divide the class into two teams and have them line up, shoulder-to-shoulder and
face the other team. Stand at one end of the lines and have the farthest student on
both teams hold a set of index cards.
1. Say the name of a robotics part and have the student on each team holding the
set of index cards look for that picture of the robotics part.
2. Once they have found the appropriate index card, have them pass it to the
teammate standing next to them. Each team member must pass the card to the
person standing next to him or her. The first team to pass the correct card to
the teacher wins.
3. Return the cards to each set and have the student who searched for the card in
the last round move to the other end of the line. Continue the rounds as many
times as desired.
Was it frustrating to know that you had found the right index card but it took so
much time to pass it down to the teacher? Was it more effective in the first
activity when one person gave directions and the other person could perform the
actions immediately? What other activities in life have a time-delay?
Page 31 of 104
Activity Preparation
Tips:
Copy the worksheet for
this activity and distribute
it after the demonstration
of the activity. While the
worksheet can be done in
class, it can also be sent
home with students for
homework and to test
retention of material.
Suggestions for
Instruction:
As this is the first time
students will be building a
rover, it may be useful to
build the rover together as
a class. You can do this by
showing them the most
basic way of building it,
then allowing groups to
improve designs if they so
choose.
Classroom Instructional Strategies
Construction and Programming
1. Students should first
construct a basic rover,
which will look
something like the
picture to the right. This
basic rover can be the
base rover for many of
the activities in this
guide.
Construction Tips:
 Collect these pieces
to construct a basic
rover.
 Attach the
connectors that look
like the letter “H”
perpendicular to the
display on the NXT
brick.
Page 32 of 104
To familiarize students
with the MINDSTORMS®
program, you should
write the code in
advance and make it
available for students to
download from a single
computer. Students
should load both
programs
simultaneously, and run
each of them in turn.
This will teach students
how to choose between
programs stored on their
NXTs.
This rover has two
wheels and drags (or
pushes) the other end of
the rover on the ground.
Think of it like a
wheelchair or a tank.
Students may be inclined
to build a 4-wheeled
vehicle, but that is more
complex, so a 2-wheeled
vehicle is a good place to
begin.
 Attach the motors to
the “H connectors”
with the three pegs
near the orange part
of the motor. Make
sure the orange part
of the motor is
closest to the edge
of the NXT brick for a
stable design.
 Use cables to
connect the motors
to the lettered ports.
 Insert axles into the
center of the orange
part of the motors.
 Attach wheels to
each axle, and you’ve
finished your basic
rover.
Page 33 of 104
Make sure groups build
their rovers with the
sensors and motors
attaching to the ports
selected in the predesigned code. If
students have their
sensors or motors
attached to the wrong
ports, their rovers will
not function properly.
Make sure everyone in
each group has a chance
to try directing the rovers
before moving on to the
time-delayed rovers.
2. Once students have constructed this rover, they should attach the sensors to
the input ports that correspond to the pre-designed code. They will take the
two touch sensors, and connect one to Port 1 and the other touch sensor to
Port 2. Students should use the longest cables they have for these connections
to make it comfortable for the operator of the rover.
3. Next, students will download both
programs from the teacher’s
computer. First, students will run the
“Non-Delay” program to instruct the
NXT to move only when receiving input
from the touch sensors, with the right
wheel moving for 1 second when it
receives input from one sensor, and
the left wheel moving for 1 second
when it receives input from the other.
Place all these icons inside a loop. The code looks like this:
4. Hold the touch sensor from Port 1 in your left hand and the Port 2 touch sensor
in your right hand. Walk along with the rover as it drives forward. Pressing the
right sensor will make the right wheel move forward while pressing the left
sensor will make the left wheel more forward.
5. Once each student has tried the code without a delay, instruct students to
select and run the “Delay” program loaded on their NXT. Using the program
with the built-in delay simulates controlling a rover from a greater distance. The
code is the same as above with a Wait icon inserted before each Move icon that
waits for 5 seconds. The code looks like this:
Page 34 of 104
Discussion and Observations
 Was it harder to control the rover with or without the delay? Why?
 What would be a more effective design for the Mars Rover: a remote controlled rover or an autonomous
rover? Light travels at 299,792 km/second (or 186,282 miles/second). When we communicate with Mars we
have to use light or radio waves, which can’t go any faster than this. That means to send a command to our
rover it will take 13 minutes to get there, and 13 minutes for the rover to send back any answer to our
command. When you try to drive your rover on the floor with the delay it’s really tough, right? If the rover was
on a delay, scientists would have to send only one movement every 13 minutes, and it would take too long to
get anywhere on Mars. Also, there would be no way to respond in time to obstacles that were previously
unknown. Therefore, the rover needs to be able to navigate on its own (autonomously).
Optional Activity Variations
Have group members empty a space on the floor or table. Place an object that will be the goal destination for the
rover. Blindfold one member of the group who will be the controller of the rover. Have the other members of the
group or the teacher place the rover at least two feet away from the end destination. Using the “Non-delay”
program, the blindfolded member of the team must control the rover while the other group members give
directions on which way to steer the rover. Let each group member have a chance at steering the rover blindfolded.
Discuss how the team worked together and why teamwork is so important in engineering and everyday life.
For Further Discussion
 Based on what you learned in this activity, how do you think a remote control for a television works? Most
television controls work by using infrared signals to send information from the control to the television. The
remote sends out a series of pulses of light, which differ depending on which button you press on the remote.
This can be thought of as similar to Morse code. The remote sends out pulses of light in a code that the
television can understand when the light reaches the set.
Page 35 of 104
Name: ________________________
Remote Controlled Rover
Today we will be building a remote controlled rover. We will also be learning more about Mars and
what happens when signals are sent from Earth to the rovers on Mars.
Answer the questions below before building the rover.
1. What is the average distance between Mars and Earth?
2. Why does a signal from Earth to Mars have a delay?
Build a basic rover with help from your teacher. After you have completed your rover, download and
run each of the provided programs.
Answer the questions below in complete sentences.
3. Was it more difficult to drive the rover with or without a delay? Explain in detail.
4. Define autonomous. Explain why the Mars rovers need to be autonomous.
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Activity #4:
Drive Forward
In this lesson, students will learn how to design, build and program a basic Mars Rover. This rover will incorporate
the NXT brick in the design and will be programmed to function autonomously.
In previous activities, students built a basic rover from their teacher's model and downloaded NXT programming
previously designed by the teacher. In this activity, they will turn their creativity towards designing functional yet
dynamic models. While they may be aware of what the actual Mars Rover looks like, students should be
encouraged to experiment with other designs, as a breadth of designs in the classroom will open the door for
discussions about optimal designs for a variety of external conditions on Mars.
Students will also have to design and build as a team, and teachers should use peer-learning techniques to optimize
group dynamics.
Learning Goals
Students will design and build their own rover.
While students may begin from the model
proposed in this guide, they should be encouraged
to engineer improvements.
Students will successfully build a rover and will
theorize about modifications to improve this
design.
Washington State EALRs Addressed in this Activity
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 APPD The process of technological design begins by
defining a problem and identifying criteria for a successful
solution, followed by research to better understand the
problem and brainstorming to arrive at potential solutions.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
6-8 APPF Solutions must be tested to determine whether or
not they will solve the problem. Results are used to modify
the design, and the best solution must be communicated
persuasively.
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Reviewing Prior
Knowledge
In prior grades
students:
 Learned to work
individually and
collaboratively to
produce a product
of their own
design.
 Learned to plan
investigations to
match a given
research question.
Vocabulary
 NXT
 “Brick”
 Sensors
Materials
 LEGO® kits (1 per
group of 2-4
students)
 Worksheets
(included in this
guide)
 Overhead device
(for projecting NXT
program for class
observation)
Before the Activity:
Teacher Preparations:
Kits and computers should be prepared before class begins. This includes loading the
NXT program on laptops prior to class beginning, charging batteries for NXT bricks,
and making sure each kit has parts necessary for the day’s activity.
Resources for Educators:
Informative Website: “The rover´s wheels "legs"
Link: http://bit.ly/b5Qn3M
This link will give students more details about the rover’s wheels and how quickly and
effectively they can propel the rover over Mars’s terrain.
Videos: “Space Week – Roving Mars Rover 1”
Link: http://bit.ly/cLt10u
“Space Week – Roving Mars Rover 2”
Link: http://bit.ly/c7ajtD
These two videos (2 min. and 5 min, respectively) are excellent introductions to the
building and launching of the Mars Rover. In particular, the first video is focused on
engineering Mars rovers, which ties into this lesson and can be used as an
engagement activity.
Fun Resources for Students:
Books: "Cars on Mars: Roving the Red Planet" by Alexandra Siy
Link: http://amzn.to/94Bsp4
Interactive Website: “Drive a Rover”
Link: http://bit.ly/aBu3Iy
Video: “Free Spirit – Exploring Options”
Link: http://bit.ly/9XUtF7
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Robotics Theory:
Engagement Activities
Generally, mobile
robots are designed
with two motors in the
back, one for each
wheel, and a center
un-motorized pivot
wheel in the front. This
allows the rover to
turn easily by having
only one motor on and
to drive in a straight
line by having both
motors on. It can also
pivot in place by
turning on one motor
forward and one
motor backwards.
Rotating Robots:
When teaching
students how to build
and program their
basic rovers, make
sure you pick one
method for all groups
to follow. This will
eliminate confusion
between groups,
particularly in later
weeks when students
switch groups.
1. Have the students split into groups of four and spread around the room.
2. Each group should form a square so that two students are in front of the other
two students and are all facing the front of the classroom. Have the students in
back put his or her outside hand on the outside shoulder of the students in front.
Have the front students put their hands on each other’s shoulders. Have the back
students do the same.
3. Tell all the students that they must keep their hands on each other’s shoulders
and keep their arms extended.
4. Stand at the front of the room, and have all the students (staying in this
formation) turn to face you.
5. Call out specific walls for the students to face, slowly increase speed until the
students begin to work out a method of turning quickly. Increase the pace for
fun.
a. Consider using more complicated commands like “turn all the way around
and face the same wall”, or “turn to face me, then turn 90 degrees to your
left.”
6. Discuss with the students which methods of turning worked the best and which
didn’t seem to work at all.
a. Did they always turn around one corner?
b. Did the left side move forward while the right moved back?
c. Did they all try to move around the center?
d. What worked, what didn’t? What could we make a robot do?
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Activity Preparation
Tips:
Copy the worksheet
for this activity and
distribute it after the
demonstration of the
activity. While the
worksheet can be
done in class, it can
also be sent home
with students for
homework and to test
retention of material.
If there are a limited
number of laptops for
groups to share,
assign groups to
either be builders or
programmers first.
Have groups start at
their assigned
stations and switch
once they are
completed. This will
help you avoid long
delays as students
work at computers.
Classroom Instructional Strategies
Group Assignments Tips:
Here are suggested roles for groups of four students:
 Designer: While the group brainstorms, the designer sketches what the rover
will look like and troubleshoots mechanical problems.
 Builder: Other group members search for appropriate pieces in the kit while the
builder actually constructs the rover and troubleshoots mechanical problems.
 Code-writer: This student writes down the code that the group will program the
robot with and troubleshoots programming issues.
 Programmer: With group members double-checking and providing support, the
programmer sits at the computer to digitalize the code that the code-writer
provides and troubleshoots programming issues.
These roles can be assigned by the teacher or decided among the group members.
Make sure students rotate through all the roles in different activities. Let them
reflect on which role they like the best. While it is helpful in some situations to
assign roles so that all have a chance to participate, some classes may find such
roles too rigid or unnecessary.
Group Design and Brainstorming
Have each student draw a picture and make notes on what they want their rover to
look like. Within their groups, let students discuss the best parts about each other
models. Have students choose at least one feature from each group member’s
drawing for the “designer” to compile into a detailed picture of the group’s rover.
Remind groups to reference the brainstorm ideas from the engagement activity.
Building the Rovers
Beyond the basic construction tips listed below (similar to those included in Activity
#3), students should be encouraged to express creativity and explore the range of
parts within the kit that would produce a more efficient rover.
Construction Tips:
 The most basic LEGO® rover consists of:
o Two motors under the back of the NXT, with wires connected to the lettered
ports, which provide power output.
o Reinforce the motors (so they stay on the rover) with LEGO® strips
connecting both motors.
o Attach wheels to the motors using axles.
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Troubleshooting:
Problem: Rover moves
in the “wrong”
direction.
Solution: The motors
are programmed to
have “forward” in a
particular direction.
The Rover will move in
the “right” direction if
you physically turn the
motors around, or if
you change the
direction in the
“move” block.
Problem: Front of
Rover catches on the
ground, and moves in
fits and starts.
Solution: Some
surfaces, especially
carpet, do not allow
the Rover to slide
smoothly. This can be
fixed by placing the
Rover on a table,
cardboard, or similar
surface, or by
attaching front wheels
or ski-like objects to
the front of the rover.
Another solution is to
turn the Rover around
so that the motors
drag the NXT behind
instead of pushing it in
front.
Problem: Only one
motor moves when
the program is
running.
Solution: Make sure
that the motors are
connected to the same
lettered ports that are
selected in the move
icon of the code.
Programming the Rovers
1. Once students have designed their rovers, they should design their programs.
Before students attempt to write the programs on the computers, groups should
be asked to write out in words what they want the rovers to do. This should
include:
 Both wheels driving forward when the program is started
 Rover driving at X speed and for Y period of time
Sample Code:
This program tells the rover to:
 Turn on motors A and C in the forward direction for a timed amount (e.g. 3
seconds).
Testing and Modifying the Rovers
Groups should test that their rovers drive forward for the amount of time they
programmed in their code. Let students know that engineers design products, do
trials, and modify their design many times. Your rover may not perform exactly how
you want in the first trial. Encourage students to work as a team to recognize what is
going wrong with the rover. Is it a problem with the code or with the physical rover?
Use the troubleshooting tips to help students find solutions to their rovers’
problems. Even if a group’s rover performs correctly the first time, allow students
this time to modify certain aspects of the design or code, such as speed, direction or
wheel size.
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Discussion and Observations
 Looking at other groups’ designs, which designs would be best suited for Mars? Why? Rovers with treaded
wheels and good turning capabilities would be well suited for the terrain of Mars. Also, rovers should be
functional and sturdy but not contain extraneous parts. Scientists that send rovers to Mars do not want to pay
for extra materials and potentially deal with parts breaking that don’t need to be there in the first place.
 Keeping the programmed speed the same, how would you make your rover go faster? How about slower?
Use wheels that are larger in diameter to make the rover go faster. Use wheels that are smaller in diameter to
make the rover go slower.
 Did your rover go in the direction you expected? Why or why not? What did you do to correct it? “Forward” is
a particular direction for the motors, and physically turning the motors around on your rover’s design will make
the rover go in the opposite direction. If the rover was veering off in one direction, check that the tires are not
pegged too closely to the rover or that nothing (i.e. a wire) was blocking a tire from spinning freely.
Optional Activity Variations
Budgeting Your Models
Set limits – put a price on each of the parts, and tell students they have a limit to how much they can spend and
that they must spend X amount on the requisite parts (what it would take to build a basic rover).
Testing Surfaces
 When the rovers are built and have been programmed, have the different designs drive on the different
surfaces that you might find around the classroom.
a. Is it easier to drive on linoleum or carpet?
b. Whose wheels work the best? Why?
c. Which construction works best? Why?
d. Based on the results, which rover would be the best for navigating a sandy terrain? A rocky terrain?
For Further Discussion
The newest Mars rover, Curiosity, launched from Earth on November 26, 2011, 7:02 a.m. PST and landed on Mars
on August 5, 2012, 10:32 p.m. PDT. Take a look at information about Curiosity from the NASA website:
http://mars.jpl.nasa.gov/msl/mission/overview/ Depending on when you are teaching these lessons, Curiosity
could be exploring the surface of Mars right now! Science is advancing and changing as we speak. Scientists are
doing very important work in our world so we can make informed choices. Ask your students: if you decide to
become a scientist, what areas would you like to focus on? How would it affect people’s lives?
Page 42 of 104
Name: __________________________
Drive Forward
During the previous class you were introduced to the NXT software and learned how to program a
rover. Today, you will be using those skills to build a motorized rover and write a program that tells
the rover to drive forward.
As a team, build a rover with your NXT brick.
1.
Before writing your program, describe the program you plan to write below.
As a team, write and download a program to your NXT brick that will cause the rover to drive
forward.
Answer the questions below in complete sentences.
2. How could you make your rover move faster? How could you make it move slower?
3. Did your rover do anything unexpected (like going the wrong way, or turning)? If so, describe
what it did and why it may have done it.
4. Describe any mistakes you made in either the rover's design or the programming and how your
team fixed these mistakes.
Page 43 of 104
Mars Rover Unit Two Overview:
Through a series of six hands-on lessons, students will explore the use of sensors and different characteristics of
the environment on Mars through the following activities. In the first activity in this unit, students will design and
build a rover that drives around and stops before it hits another object, like a wall. In the second activity, students
will build on the previous lesson by using a loop function to engineer a robot that drives around until it is about to
hit another object, backs up, and repeats these actions. The third activity explores how the solar patterns of Mars
affect the rover’s power. Students will design, build and program a rover that moves while the lights in the
classroom are on but stops when the lights are off. In the fourth activity, students will engineer a rover that uses a
light sensor to stay on the surface of a table and not fall off similar to the rover on Mars that avoids falling into
craters. The fifth activity explores the rims of craters on Mars in which students build a line-following robot. In the
final activity, students will simulate designing and testing a robot that detects water on Mars.
The lessons of this unit can be used in isolation, or as a group.
Grade level: 6-8
Group size: 2-4
LEGO® Materials needed: LEGO® MINDSTORMS® NXT 2.0 Set with corresponding MINDSTORMS® software
Contents:
Page 47
Activity #5: Avoid Martian Rocks
54
Activity #6: Explore Mars
61
Activity #7: Power Down at Night
68
Activity #8: Don’t Fall Into Craters
75
Activity #9: Crater Rim Exploration
82
Activity #10: Finding Water on Mars
Learning Objectives for All Lessons:
 Students will understand the basics of NXT programming, which allows the technological instrument (the
“brick”) to respond to external stimuli and complete students’ designs.
 Students will design and build their own rover as before, and will learn how to incorporate and adjust a:
o Distance sensor sensitive to obstacles
o Light sensor that can perceive changes in ambient light and that will determine the edges of the
table/”crater” or line/"crater"
 Students will theorize about modifications to improve this design.
 Students will consider the obstacles faced by the rover and consider similarities and differences between the
terrain on Earth and Mars. They will also consider:
Page 44 of 104
o The challenges of powering a rover without batteries or fuel
o The danger of uneven terrain for an autonomous robot on this planet
 Students will observe how the rover model perceives differences in light, and will draw connections between
this model and the Mars Rover, which uses solar energy to function.
 Students will draw connections between the asteroids that struck and cratered Mars and those that shaped
Earth’s terrain.
Educational Standards Addressed:
National Standards: Science
NS.5-8.1 SCIENCE AS INQUIRY
As a result of activities in grades 5-8, all students should develop:
 Abilities necessary to do scientific inquiry
 Understanding about scientific inquiry
NS.5-8.2 PHYSICAL SCIENCE STANDARDS
As a result of their activities in grades 5-8, all students should develop an understanding of:
 Motions and Forces
NS.5-8.4 EARTH AND SPACE SCIENCE STANDARDS
As a result of their activities in grades 5-8, all students should develop an understanding of:
 Earth in the solar system
NS.5-8.5 SCIENCE AND TECHNOLOGY STANDARDS
As a result of their activities in grades 5-8, all students should develop:
 Abilities of technological design
 Understanding of science and technology
Washington State Standards: Science
6-8 INQ SCIENCE AS INQUIRY
As a result of activities, students will learn that:
 6-8 INQC Collecting, analyzing, and displaying data are essential aspects of all investigations.
 6-8 INQE Models are used to represent objects, events, systems, and processes. Models can be used to test
hypotheses and better understand phenomena, but they have limitations.
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 6-8 INQF It is important to distinguish between the results of a particular investigation and general conclusions
drawn from these results.
6-8 APP SCIENCE, TECHNOLOGY AND PROBLEM SOLVING
As a result of activities, students will learn that:
 6-8 APPD The process of technological design begins by defining a problem and identifying criteria for a
successful solution, followed by research to better understand the problem and brainstorming to arrive at
potential solutions.
 6-8 APPE Scientists and engineers often work together to generate creative solutions to problems and decide
which ones are most promising.
 6-8 APPF Solutions must be tested to determine whether or not they will solve the problem. Results are used to
modify the design, and the best solution must be communicated persuasively.
6-8 PS1 FORCE AND MOTION
As a result of activities, students will learn that:




6-8 PS1A Average speed is defined as the distance traveled in a given period of time.
6-8 PS1B Friction is a force that acts to slow or stop the motion of objects.
6-8 PS1C Unbalanced forces will cause changes in the speed or direction of an object's motion.
6-8 PS1D The same unbalanced force will change the motion of an object with more mass more slowly than an
object with less mass.
6-8 PS3 ENERGY: TRANSFER, TRANSFORMATION, AND CONSERVATION
As a result of activities, students will learn that:
 6-8 PS3A Energy exists in many forms: heat, light, chemical, electrical, motion of objects, and sound. Energy can
be transformed from one form to another and transferred from one place to another.
 6-8 PS3E Energy from a variety of sources can be transformed into electrical energy, and then to almost any
other form of energy. Electricity can also be distributed quickly to distant locations.
6-8 ES1 EARTH AND SPACE SCIENCE
As a result of activities, students will learn that:
 6-8 ES1B Earth is the third planet from the sun in a system that includes the Moon, the Sun, seven other major
planets and their moons, and smaller objects such as asteroids, plutoids, and comets. These bodies differ in
many characteristics (e.g., size, composition, relative position).
 6-8 ES1B Earth has been shaped by many natural catastrophes, including earthquakes, volcanic eruptions,
glaciers, floods, storms, tsunami, and the impacts of asteroids.
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Activity #5:
Avoid Martian Rocks
In this lesson, students will use engineer a rover that will avoid objects in its path. Students will draw connections
between the rover model and the actual Mars Rovers, which have to avoid objects using sensor technology similar
to bats’ echolocation. In this activity, students will use an ultrasonic distance sensor and NXT programming to help
their rovers detect objects in their paths.
This activity will build on the previous activity in which students developed rovers that were autonomously
propelled by NXT programming and motorized wheels. In this activity, we will be adding a basic command from a
sensor to help students learn how their NXT-programmed rovers can respond to external stimuli. This activity will
preface activities in which more complex programming, like loops, are included.
In addition to programming and engineering experience, students will gain a better understanding of how the Mars
Rover functions autonomously on the terrain of Mars. Student will likely draw connections between the uneven
terrain on Earth—particularly in mountainous regions, including the Cascades—and the dusty and rocky façade of
Mars.
Learning Goals
Students will understand the basics of NXT
programming, which allows the technological
instrument (the “brick”) to respond to external
stimuli and complete students’ designs.
Students will design and build their own rover as
before, and will learn how to incorporate and
adjust a distance sensor sensitive to obstacles.
Students will successfully build a design and will
theorize about modifications to improve this
design.
Students will consider the obstacles faced by the
Mars Rover and consider similarities and
differences between the terrain of Earth and Mars.
Washington State EALRs Addressed in this Activity
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
6-8 APPF Solutions must be tested to determine whether or
not they will solve the problem. Results are used to modify
the design, and the best solution must be communicated
persuasively.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
Page 47 of 104
Reviewing Prior
Knowledge
In prior grades
students:
 Learned to work
individually and
collaboratively to
produce a product
of their own
design.
 Learned to plan
investigations to
match a given
research question.
Vocabulary
 Terrain
 Echolocation
 Sonar
Materials
 LEGO® kits (1 per
group of 2-4
students)
 Worksheets
(included in this
guide)
 Overhead device
(for projecting NXT
program or online
videos)
Before the Activity:
Teacher Preparations:
Kits and computers should be prepared before class begins. This includes loading the
NXT program on laptops prior to class beginning, charging batteries for NXT bricks,
and making sure each kit has parts necessary for the day’s activity.
Resources for Educators:
Article: “The Rover’s ‘Neck and Head’”
Link: http://1.usa.gov/YWwVRZ
This article builds on the article posted in last lesson’s resource area, which was
focused on the rover’s wheels and how they helped with navigation.
Interactive Website: “Laboratory Rover in the JPL Mars Yard”
Link: http://bit.ly/aeYkta
This interactive website can be used as an engagement activity so students can get a
better sense what the parts of the Mars Rover are, and how they work to help us
learn about Mars. It features actual photos of the Rover and allows students to zoom
in and rotate the models.
Fun Resources for Students:
Interactive Website: “Drive a Rover”
Link: http://bit.ly/aBu3Iy
Interactive Website: “Where Would You Land a Rover to Look for Life?”
Link: http://bit.ly/cwscXq
Page 48 of 104
Tips and Tricks:
Engagement Activities
Consider creating a
code for a simple
robot that makes a
higher or lower
pitched noise based
on how far away an
object it. Student can
then put blindfolds on
to navigate around
the room based on
the tone emitted
from the robot.
Instructions for this
code can be found in
Technically Learning’s
Robotic Animals
curriculum.
Lesson Plan for Activity: “Bats and Echolocation”
Link: http://to.pbs.org/cr20T9
These exercises can be a useful way to draw connections between organic beings’
ability to navigate and the Mars Rovers’ ability to navigate without human “eyes.” It
will help you link senses, perceptions and responses in animals and humans to the
rover’s sensors. Because the sensor here uses echolocation, this activity will help
draw important connections.
Remember: the
orange button on the
brick selects options
while the grey
rectangular button
goes back.
Echolocation Activity (Using Robotics Kits):
1. Have the students split into as many groups as there are kits for the classroom.
2. Using the instructions below, make the NXT display how far an object is away
from the ultrasonic distance sensor on the screen.
 Attach the ultrasonic distance sensor to the NXT brick using a wire cable.
Make sure it is attached to one of the numbered ports.
 Press the orange square on the brick to turn it on.
 Press the right arrow until you get to the “View” option. Press the orange
button to select “View.”
 Press the right arrow until you reach “Ultrasonic inch” (or “Ultrasonic cm”
depending on what you prefer) and press the orange button to select.
 Select the port your sensor is plugged into.
 You should now see the value that the ultrasonic distance sensor is reading.
3. Have each student in the group take turns exploring the room while only
looking at the display screen.
a. Was this a reliable way of navigating the room?
b. What are the limitations of the ultrasonic distance sensor?
c. What kinds of animals use echolocation?
Page 49 of 104
Activity Preparation
Tips:
Copy the worksheet
for this activity and
distribute it after the
demonstration of the
activity. While the
worksheet can be
done in class, it can
also be sent home
with students for
homework and to test
retention of material.
Classroom Instructional Strategies
Building and Programming the Rovers
[NOTE: While these instructions are numbered, students can write their program
and build their rovers in any order.]
1. Have students build a basic rover in their groups. Refer to rover instructions
from Activity #3 for guidance on basic structure of the rover. Students will be
adding a distance sensor using the numbered ports to the front of their rovers.
Make sure the distance sensor is pointed forward. A sample rover with a
distance sensor is pictured below:
If there are a limited
number of laptops for
groups to share,
assign groups to
either be builders or
programmers first.
Have groups start at
their assigned
stations and switch
once they are
completed. This will
help you avoid long
delays as students
work at computers.
2. Have students write the code that would tell the rover to drive forward and
stop when it perceived an object less than 10 inches away.
Sample Code:
This program tells the rover to:


Turn on motors C and B in the forward direction for an unlimited duration.
They will stay on until another command tells them to turn off.
Wait until the distance sensor detects an object less than 10 inches away
(use the slider on the properties panel to change the default 50 inches to
10 inches)
Page 50 of 104

Then
stop
both C
and B
motors
Troubleshooting
Tips:
Problem: Rover
continually drives
forward, without ever
sensing an object.
Solution: There are
several possibilities.
First, verify that the
sensor is connected to
the proper port. Also,
make sure the sensor
is facing forward, and
that the program block
is set to wait until an
object is less than the
specified distance. You
can verify that the
sensor is programmed
properly by placing
your hand directly in
front of the sensor and
seeing if the wheels
stop.
Testing the Rovers
1. Groups should find a space where they won’t run into each other, and should run
their programs. They should make sure there will be some objects in their path
that will trigger the “turn off” portion of the program. Work with groups to
troubleshoot as necessary.
2. Challenge students to test if their rover can detect and stop for objects of
different sizes, textures and appearances. Below, we ask about pencils and glass,
but you could also select objects around the classroom that might present more
of a challenge. The distance sensor looks like eyes (or robot eyes, at any rate)
and uses echolocation to sense distance which is different that the light that our
eyes use for sensing. To reinforce this fact, turn off/dim the lights and have
students see if the robots will still perceive objects in its path.
3. If you have time, give students time to modify their design or their program to
make it more effective at perceiving distance. This may include adjusting the
sensor’s position or refining the program. (Advanced groups can do the
advanced optional activity variation.)
Discussion and Observations
 Are there any objects that your rover couldn’t detect?
o Could it detect glass? Yes, the sound pulses would reflect from the glass.
o Could it detect a pencil lying on the ground? No, the pencil is too small to be
detected by this sensor.
 Would this rover be able to drive around Mars? This rover wouldn’t be able to
detect small rocks and obstacles, and would probably have a hard time
navigating the landscape. The real Mars Rover uses multiple techniques to detect
objects, including cameras, lasers, and probes.
 Thinking about the terrain and atmosphere (including dust storms!) on Mars,
what are some challenges that might interrupt the distance sensor’s abilities
on that planet?
Page 51 of 104
Optional Activity Variations
Testing accuracy
An important part of being a scientist is performing experiments and testing the validity of those experiments. Set
your robot to stop in front of a wall, and measure with a ruler how far the distance sensor is away from the wall. Do
this at least five times to verify your findings. Did the robot stop the proper amount away from the wall every time?
Why is it important to check this? Why is it important to do this test many times over again? Do you think the actual
Mars Rover is more accurate than your rover? Do experiments always work out perfect the first time?
For Further Discussion
 How do distance sensors work? Sensors allow the rover to gain information about its surroundings. The
program can then make decisions based on this information. The ultrasonic distance sensor uses sound pulses to
determine the distance to an object in front of the rover. The sensor measures the amount of time between
when it sends out the pulse of sound and when it detects the reflected sound pulse. This sensor works by making
a little noise, then listening for the echo. If the echo comes back really quickly it knows something is close by, if it
takes a while it knows the object is further away. This is the same technique that is used by bats to navigate in
the dark. The Mars Rover uses similar techniques with light pulses to determine the distance to objects on the
surface of Mars.
 How do scientists determine how to program the sensors on the Mars Rover? This video, titled “Rover First
Steps” (http://marsrovers.jpl.nasa.gov/gallery/video/hardware.html, located near the bottom of the page),
explains how: NASA engineers had to figure out what size rock is too big to roll over. They did this through
extensive testing on Earth. The real rovers are able to drive over very difficult terrain. This would be an excellent
moment to compare terrain on Mars and Earth.
Page 52 of 104
Name: _______________________
Avoid Martian Rocks
Today we will be learning about ultrasonic distance sensors. Additionally, we will be designing and
building a rover that will drive forward until it senses an object.
Before you begin the activity answer the questions below:
1.
If you could invent any sensor you wanted to for your rover, what would it sense?
2.
How does an ultrasonic sensor work?
Build and program a rover that drives forward until it senses an object. After you have built and
tested your rover answer the questions below.
3. Were there any objects that the rover could not detect? Why?
4. Describe something you have seen in your life that has similar behavior to your rover (e.g., stops
moving when something is in the way).
Page 53 of 104
Activity #6:
Exploring Mars
In this lesson, students will engineer a rover that will avoid objects in its path by switching directions and continuing
along a new trajectory. Students will draw connections between the rover model and the actual Mars Rovers,
which have to avoid objects using sensor technology similar to bats’ echolocation. In this activity, students will use
an ultrasonic distance sensor and NXT programming to help their rovers detect objects in their paths and will use a
more advanced version of the program from the previous lesson to create a vehicle closer to the Mars Rover’s
actual functions.
This activity will build on the previous activity in which students added basic programming for a sensor so their NXTprogrammed rovers could respond to external stimuli. This activity will include a programming loop, and
potentially could run indefinitely.
In addition to programming and engineering experience, students will gain a better understanding of how the Mars
Rover functions autonomously on the terrain of Mars. This will link activities from Unit One so that students can see
how scientists iteratively build on their designs to make the most effective models.
Learning Goals
Students will understand the basics of NXT
programming, which allows the technological
instrument (the “brick”) to respond to external
stimuli and complete students’ designs.
Students will design and build their own rover as
before, and will learn how to incorporate and
adjust a distance sensor sensitive to obstacles.
Students will successfully build a design and will
theorize about modifications to improve this
design.
Students will consider the obstacles faced by the
Mars Rover and consider similarities and
differences between the terrain of Earth and Mars.
Washington State EALRs Addressed in this Activity
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
6-8 APPF Solutions must be tested to determine whether or
not they will solve the problem. Results are used to modify
the design, and the best solution must be communicated
persuasively.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
Page 54 of 104
Reviewing Prior
Knowledge
In prior grades
students:
 Learned to work
individually and
collaboratively to
produce a product
of their own
design.
 Learned to plan
investigations to
match a given
research question.
Vocabulary
 Iterations
 Looping
 Navigation
Before the Activity:
Teacher Preparations:
Kits and computers should be prepared before class begins. This includes loading the
NXT program on laptops prior to class beginning, charging batteries for NXT bricks,
and making sure each kit has parts necessary for the day’s activity.
Resources for Educators:
News Article: “Rover Navigation During Surface Operations”
Link: http://1.usa.gov/10jX2TU
This article explains how the rover’s judge distance and determine where and how to
get to different points on Mars.
News Article: “The rover’s body”
Link: http://1.usa.gov/XgXO9d
This article continues to explore the parts of the rover, building on the articles posted
in the last two lessons.
Materials
 LEGO® kits (1 per
group of 2-4
students)
 Worksheets
(included in this
guide)
 Overhead device
(for projecting NXT
program for class
observation)
Fun Resource for Students:
Book: Mars by Stuart Murray
Link: http://amzn.to/bJxK9S
Interactive Website: “Sights and Sounds from a Mars Never Dreamed Of”
Link: http://bit.ly/dd20Sa
Interactive Website: “Earth or Mars?”
Link: http://bit.ly/dBVmZa
Page 55 of 104
Tips and Tricks:
This engagement
activity involves a lot
of brainstorm work.
Consider having
students pair up or
work in their robotics’
groups to come up
with ideas for these
questions. Once
groups have
generated enough
ideas, they can be
shared with the
whole class to
stimulate more
discussion.
Engagement Activities
1. Students may have anticipated the introduction of the loop as the natural next
step to the model they built last class. Have students brainstorm how they
would add on or complete their program to make the rover fully autonomous
(even when it runs into objects).
 Students might think about cars. What do they do when they run into a
dead-end street?
 What about a Roomba® (autonomous floor vacuum) – how does it work?
2. Often we need to tell a computer to do something more than once. Sometimes
we want the loop to continue forever, but other times we want it to stop after a
certain amount of time.
 Can you think of a machine or program that we program to continue to run on
a loop? What types of activities do these programs/machines run, and how is
the loop useful for its function? Answers may include things like digital alarm
clocks, because we need them to regularly wake us up in the morning.
 Can you think of programs that work for a limited period of time?
Page 56 of 104
Activity Preparation
Tips:
Copy the worksheet
for this activity and
distribute it after the
demonstration of the
activity. While the
worksheet can be
done in class, it can
also be sent home with
students for
homework and to test
retention of material.
Classroom Instructional Strategies
Building and Programming the Rover
[NOTE: While these instructions are numbered, students can write their program and
build their rovers in any order.]
1. Have students build a basic rover in their groups. Refer to rover instructions from
Activity #3 for guidance on the basic structure of the rover. Students will be
adding a distance sensor using the numbered ports to the front of their rovers.
Make sure the distance sensor is pointed forward. A sample rover with a
distance sensor is pictured below:
If there are a limited
number of laptops for
groups to share, assign
groups to either be
builders or
programmers first.
Have groups start at
their assigned stations
and switch once they
are completed. This
will help you avoid
long delays as students
work at computers.
Programming
Theory:
Loops are used in
programming to create
behaviors that repeat
infinitely or for a
specified number of
times.
2. Have students write the code that would tell the rover to drive forward and stop
when it perceived an object, change direction, and then proceed like this
indefinitely.
Sample Code:
This program tells the rover to:
 Turn on motors C and B in the forward direction for an unlimited duration.
They will stay on until another command tells them to turn off.
Page 57 of 104
Troubleshooting
Tips:
Problem: When the
rover senses an object,
backs up and drives
forward again, the
rover hits the same
object.
Solution: The rover
needs either to take
more time backing up
or a more pronounced
turn while backing up
to gain enough
clearance to drive past
the object.
Problem: When the
rover senses an object
and backs up, it backs
into the object it was
trying to avoid.
Solution: The rover
should back up for less
time or fewer
rotations. The rover
might also need to
take a less intense
curve while backing
up.
Remember: the grey
rectangular button on
the NXT brick will stop
a program that is
currently running.
 Wait until the distance sensor detects an object less than 10 inches away
(use the slider on the properties panel to change the default 50 inches to 10
inches).
 Then change the motors in the following ways:
o Go in the backwards direction.
o Use the steering slider to make it turn while going backwards.
o For a short duration (e.g. 5 rotations or 2 seconds).
 Loops back to the beginning of the program, to repeat these commands
infinitely.
Testing the Rovers
1. Groups should find a space where they won’t run into each other and should run
their programs. They should make sure there will be some objects in their path
that will trigger the “back up” portion of the code. Work with groups to
troubleshoot, as necessary.
2. If you have time, give students time to modify their design or their program to
make it more effective at perceiving distance or backing up. This may include
adjusting the sensor’s position or refining the program.
Discussion and Observations
 How long will this rover keep roaming?
This program will keep looping infinitely. The rover will roam until it runs out of
batteries, you stop it, or it breaks apart from hitting obstacles that the sensor
misses.
 Did your rover eventually fall apart? What can you do to make it stronger?
Reinforce all of the pieces connected to the NXT.
 Did your robot continue to have problems even after it changed directions?
How did you make adjustments so it ran more smoothly?
 How would this model fare on Mars, compared to the last one you built? What
are some dangers a rover might run into if it continued to roam around Mars?
Responses to the latter question might include falling into a crater if it travelled
aimlessly around the terrain, since the distance sensor would not sense holes
beneath the rover. This will be something addressed in later lessons, but students
will benefit from contemplating it now.
Page 58 of 104
Optional Activity Variations
Experimenting with loops
Now that students have successfully created a robot that uses a loop, let them experiment with loops in their code.
What happens if you put another icon before your loop? What happens if you put an icon after your loop? Have
your students predict what will happen in each case.
The icon that is placed before the loop will happen once and then the robot will continue repeating the actions in
the loop. An icon placed after a loop will not be executed unless you specifically tell your loop to repeat a certain
number of times. If the loop if set indefinitely (which is the default setting), the robot will never get to an icon that
is after it.
For Further Discussion
Scientists and engineers work very hard to create a rover that will be able to navigate around Mars. As part of the
design process, scientists test the rover here on Earth first before they send it into space. Mars Rover prototypes
are usually tested in desert locations, as that is the closest we have on Earth to a Martian landscape. You can check
out more about the field tests done with a test rover named FIDO here: http://marsprogram.jpl.nasa.gov/mer/fido/
There were even high school students who worked as interns along NASA scientists during the field tests. Would
you like to be a part of a Mars rover team?
Page 59 of 104
Name: ______________________
Explore Mars
Last session, you developed a rover that drove forward until it sensed an object. Today you will be
working with that same rover but making the program more functional.
Answer the questions below in complete sentences.
1. How could you redesign the program for your rover from last session so that it would be even
better for exploring the terrain on Mars?
2. What is an infinite loop? Does it ever stop?
Re-write the program for the rover as it was specified in class. After you have programmed and
tested the rover, answer the questions below.
3. How long will the rover keep moving after you start the program? Explain.
4. Name three things that could stop the rover from moving.
5. If your rover was selected to go to Mars, do you think it would be able to drive around
successfully? Why or why not?
Page 60 of 104
Activity #7:
Power Down At Night
In this lesson, students will engineer a rover that moves when light sources are present and stop when light sources
are absent. Students will draw connections between the rover model and the actual Mars Rovers, which are
powered by solar energy. In this activity, students will use a light sensor and NXT programming to help their rovers
determine availability of light as an “energy” source (although the rover will be powered by a battery).
This activity will build on the previous activity in which students added basic programming for a sensor so their NXTprogrammed rovers could respond to external stimuli. This activity will include a programming loop and potentially
could run indefinitely.
In addition to programming and engineering experience, students will gain a better understanding of how the Mars
Rover functions autonomously on the terrain of Mars. This will link activities from Unit One so that students can see
how scientists iteratively build on their designs to make the most effective models.
Learning Goals
Students will understand the basics of NXT
programming, which allows the technological
instrument (the “brick”) to respond to external
stimuli and complete students’ designs.
Students will design and build their own rover as
before, and will learn how to incorporate and
adjust a light sensor that can perceive changes in
ambient light.
Students will observe how the rover model
perceives differences in light, and will draw
connections between this model and the Mars
Rover, which uses solar energy to function.
Students will consider the obstacles faced by the
Mars Rover and consider similarities and
differences between the terrain of Earth and Mars.
They will also consider the challenges of powering a
rover without batteries or fuel.
Washington State EALRs Addressed in this Activity
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
6-8 PS3A Energy exists in many forms: heat, light, chemical,
electrical, motion of objects, and sound. Energy can be
transformed from one form to another and transferred
from one place to another.
6-8 PS3E Energy from a variety of sources can be
transformed into electrical energy, and then to almost any
other form of energy. Electricity can also be distributed
quickly to distant locations.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
Page 61 of 104
Reviewing Prior
Knowledge
In prior grades
students:
 Learned to work
individually and
collaboratively to
produce a product
of their own
design.
 Learned to plan
investigations to
match a given
research question.
Vocabulary
 Solar Energy
 Power
 Conservation
Materials
 LEGO® kits (1 per
group of 2-4
students)
 Worksheets
(included in this
guide)
 Overhead device
(for projecting NXT
program for class
observation)
Before the Activity:
Teacher Preparations:
Kits and computers should be prepared before class begins. This includes loading the
NXT program on laptops prior to class beginning, charging batteries for NXT bricks,
and making sure each kit has parts necessary for the day’s activity.
You might find it helpful to test this activity in your classroom before students
perform the activity. The light sensor must be set to a certain light value, which is
explained in this guide. It involves some trial and error because it is dependent on
the conditions of your classroom. While students can figure this out on their own,
you might want to know an estimate of what this value will be to be able to answer
student questions.
Resources for Educators:
Video: “Spirit's Last Moves Before Winter”
Link: http://bit.ly/a4U4tL
This video is quick feed from the Rover that shows how scientists are trying to
position the vehicle as Mars winter starts to best take advantage of the sun for
energy.
News Article: “Dust Storm Passing Over Spirit”
Link: http://bit.ly/bV4Mjo
This article explains the relationship between dust storms, solar energy panels and
the functionality of the Mars Rover.
News Article: “The Rover’s Energy”
Link: http://1.usa.gov/11Vx0Nf
This article builds on the articles previously explored in earlier lessons relating to the
rover’s structure and ability to function.
Video: “Opportunity: Waiting for the Dust to Settle”
Link: http://bit.ly/cT6mtY
This video shows dust storms can interfere with the performance and information
collected by the Mars Rover, and shows how the rovers respond to dust storms.
Fun Resources for Students:
Article: “The Devils of Mars”
Link: http://bit.ly/acdxin
Article: “Solar Basics: Energy from the Sun”
Link: http://bit.ly/dBRbr8
Page 62 of 104
Astronomy Theory:
The only power the
Mars rovers have
comes from their
solar panels.
Therefore, they are
only collecting power
during the day. Some
systems, such as
heaters to keep the
motors and
electronics from
freezing, must remain
on all the time. If the
rovers use energy by
moving around at
night, they risk
running out of battery
power. If this
happens, the systems
that are supposed to
remain on all the time
will shut off, risking
major damage to the
rover. It is therefore
necessary to stop
motion during the
Martian night. Also,
NASA engineers let
the rovers ‘hibernate’
during Martian
winters; due to the
low amount of
sunlight, the rovers
wouldn’t be able to
move. Interestingly,
dust devils
occasionally hit the
rovers, clearing off
the dust and
increasing the
efficiency of the solar
panels.
Engagement Activities
1. Energy Conservation via “Red Light, Green Light”
a. This modification of red-light green-light uses the room’s light switch
instead of calling out red-light or green-light.
b. Have all the students line up on one side of the room.
c. Turn off the light.
d. When the light is on, the students may walk (not run) to the other side of
the room.
e. When the light is off the students must freeze where they are.
f. If a student continues to walk or move after the lights are turned off they
must start again from the back wall.
g. Continue until one student makes it to the other side of the room.
 How does this relate to solar power? Have students explain what solar power is,
and how this might pose a challenge to the Rover.
Page 63 of 104
Activity Preparation
Tips:
Copy the worksheet
for this activity and
distribute it after the
demonstration of the
activity. While the
worksheet can be
done in class, it can
also be sent home with
students for
homework and to test
retention of material.
Classroom Instructional Strategies
Building and Programming the Rover
[NOTE: While these instructions are numbered, students can write their program and
build their rovers in any order.]
1. Have students build a basic rover in their groups. Refer to rover instructions from
Activity #3 for guidance on basic structure of the rover. Students will be adding a
light sensor using the numbered ports to the front of their rovers. Light sensors
should be pointing towards the ceiling to best perceive changes in light. A
sample rover with a light sensor is pictured below:
If there are a limited
number of laptops for
groups to share, assign
groups to either be
builders or
programmers first.
Have groups start at
their assigned stations
and switch once they
are completed. This
will help you avoid
long delays as students
work at computers.
2. Have students write the code that would tell the rover to drive forward and stop
when it perceives less light, then turn back on and drive for a short period after
ambient light increases again.
Sample Code:
Page 64 of 104
Sensor Tips:
You must select a light
value that separates
light from dark (i.e., a
value greater than a
room with the lights
off, but smaller than
the lights off). Deciding
on an appropriate
value may take some
trial and error.
Alternately, the
students can use the
built-in NXT functions
to display the light
sensor value to the
NXT screen and read
off the light and dark
values. Follow
instructions from the
engagement activity in
activity #5 to obtain a
sensor reading.
This program tells the rover to:
 Turn on motors C and B in the forward direction for an unlimited duration.
 Wait until the light sensor detects less ambient light in the room (classroom
lights are turned off). Change the sensor to wait until a darker light value (‘<’
symbol).
 Then stop both C and B motors.
 Wait until the light sensor detects more ambient light in the room (classroom
lights are turned back on). Change the sensor to wait until a brighter light
value (‘>’ symbol).
 Then turn on motors C and B in the forward direction.
Testing the Rovers
1. Groups should find a space where they won’t run into each other, and should run
their programs. Timing will be a little trickier with this activity because it is
dependent on the light in the classroom. All groups should get ready to run their
programs and then the lights should be adjusted while all rovers are running
their programs.
2. If you have time, give students time to modify their design or their program to
make it more effective at perceiving differences in light. This may include
adjusting the sensor’s position or refining the program by changing the values.
Troubleshooting
Tips:
If the room is really
sunny, you may need
to pull the shades
down to get this to
work.
Discussion and Observations
 Did it matter which direction your light sensor faced? Facing down at the
ground probably won’t work, as the light sensor is collecting ambient light in the
classroom, not the reflected light off the ground. Facing the light sensor up will
work best. The light sensor facing forward, left, or right may work intermittently.
 What are the advantages of solar power? What are the disadvantages?
 Can you think of anything in your daily life that is solar-powered?
 Do you think solar power would work well in Washington State? Do you think
we have enough sun? Seattle is 15% sunnier than Germany, which is the leading
producer of solar power.
Page 65 of 104
Optional Activity Variations
Day and Night
Add a loop to your program so the rover drives forward whenever lights are on (day on Mars) and the rover turns
off whenever lights go out (night on Mars). This can be achieved with a similar code that was used in this activity.
Remove the last Move icon, and place a loop around the remaining four icons.
For Further Discussion
Our eyes are a type of light sensor. Humans evolved to have very complex light sensors, but other animals don’t
have this level of development. Some animals have simple eyes called ocelli that are patches of light sensitive cells
on their skin that they use to sense how bright or dark their surroundings are. Something as simple as this can help
the animal know when to look for food or when to rest.
 Can you guess what animals have ocelli? Jellyfish, sea stars and most snails have these simple eyes called ocelli.
 How are these types of animals similar to the robot you just created? The robot you created is not able to see
someone turning on or off the lights in the classroom, but it is able to sense when the level of light in front of the
light sensor increases or decreases. Animals with ocelli are programmed in a similar way. They cannot see the
sun rise or set, but their eyes can detect when there is more or less light.
Page 66 of 104
Name: ________________________
Power Down at Night
Today the goal is to build a rover that will power off when it senses that the lights are off.
Answer the question below before working on the rover.
1. Why do the rovers on Mars need to power down at night? Explain in detail.
Build and program a rover that will drive around until the lights go off. When the lights come back
on the rover should start moving around again.
After you have designed, programmed and tested the rover, answer the questions below in
complete sentences.
2. Would the rover work if the light sensor were facing in another direction? Why or why not?
3. Describe something you have seen in your life that has similar behavior to your rover (e.g.,
powers off when not in use or the lights are off, etc.)
4. What was the hardest part about programming the rover for this activity?
Page 67 of 104
Activity #8:
Don’t Fall in the Crater
In this lesson, students will engineer a rover that drives around a plateau, detecting when it nears the edge of a
crater or cliff to avoid falling off. Students will draw connections between the rover model and the actual Mars
Rovers, which must carefully navigate Mars’s terrain to avoid “potholes” that could damage or trap the Rover,
causing expensive and difficult repairs or loss of data. In this activity, students will use a light sensor and NXT
programming to help their rovers determine the edges of “craters” (tables) and keep from falling into an abyss.
This activity will build on the previous activity in which students added basic programming for a sensor so their NXTprogrammed rovers could respond to external stimuli. This activity will include a programming loop, and
potentially could run indefinitely.
In addition to programming and engineering experience, students will gain a better understanding of how the Mars
Rover functions autonomously on Mars’s terrain. Students will experience how scientists iteratively build on their
designs to make the most effective models.
Learning Goals
Washington State EALRs Addressed in this Activity
Students will understand the basics of NXT
programming, which allows the technological
instrument (the “brick”) to respond to external
stimuli and complete students’ designs.
Students will design and build their own rover as
before, and will learn how to incorporate a light
sensor that will determine the edges of the
table/”crater.”
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
Students will draw connections between the
asteroids that struck and cratered Mars and those
that shaped Earth’s terrain.
6-8 ES3D Earth has been shaped by many natural
catastrophes, including earthquakes, volcanic eruptions,
glaciers, floods, storms, tsunami, and the impacts of
asteroids.
Students will consider the obstacles faced by the
Mars Rover and consider similarities and
differences between the terrain of Earth and Mars.
They will specifically consider the danger of uneven
terrain for an autonomous robot on this planet.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
Page 68 of 104
Reviewing Prior
Knowledge
In prior grades
students:
 Learned to work
individually and
collaboratively to
produce a product
of their own
design.
 Learned to plan
investigations to
match a given
research question.
Vocabulary
 NXT
 “Brick”
 Sensors
Materials
 LEGO® kits (1 per
group of 2-4
students)
 Worksheets
(included in this
guide)
 Overhead device
(for projecting NXT
program for class
observation)
Before the Activity:
Teacher Preparations:
Kits and computers should be prepared before class begins. This includes loading the
NXT program on laptops prior to class beginning, charging batteries for NXT bricks,
and making sure each kit has parts necessary for the day’s activity.
Resources for Educators:
Article: “Layers Piled in a Mars Crater Record a History of Changes”
Link: http://bit.ly/d8kt5h
This article explains how craters and geological layers can give scientists insight to
previous eras on Mars. This would be an appropriate source of information to
connect the geological history of Earth to that of Mars.
Audio: “Mars Up Close”
Link: http://to.pbs.org/9GXrrJ
In this audio clip, scientists explain the unexpected and previously unseen formations
found on Mars. This would be a good engagement activity to help students
understand the unusual nature of Mars in comparison to Earth.
3-D Photo Images of Spirit and Opportunity (requires 3-D glasses):
Link: http://1.usa.gov/10jZzh0
If you have or can get your hands on 3-D glasses, these are some great images to get
students more interested in Mars terrain and craters.
Video: “Entering Endurance Crater”
Link: http://1.usa.gov/X1BDS1
This video, located near the bottom of the page, shows NASA engineer explaining
how the rover navigates craters. (3.5 min.)
Fun Resources for Students:
Interactive Website: “How Craters/Canyons Form”
Link: http://bit.ly/cAuSiq
Page 69 of 104
Robotics Theory:
Engagement Activities
A light sensor pointed
down at the ground
will monitor that the
ground exists below
your rover and let the
rover know when the
edge of the table has
been reached. The
light sensor contains a
red light that reflects
off near surfaces (the
nearby table). The
clear bulb in the light
sensor picks up this
reflected red light and
reads a bright (high)
light value. When out
over the edge of the
table, the light sensor
will read a darker value
because no light is
reflected.
Feeling The Edges:
1. Have each student cut out three basic shapes out of black construction paper
(square, triangle, circle, star, etc.)
2. Each student should tape their 3 shapes onto a whole piece of white
construction paper so they can feel the edges with their fingers (don’t cover the
edges with tape).
3. Collect all the papers and shuffle them.
4. Randomly place a paper on each desk upside down.
5. Have students put on their blindfolds or close their eyes.
6. Have students flip over their pieces of paper.
7. Using only their sense of touch, have them follow the ridge of the construction
paper around and try to discover the shape that is taped to the paper.
 Was it easier or harder to determine the shape when your fingers moved
quickly? Slowly? If a robot were trying to gather data about the edges of an
object (e.g. a crater), would it be better for the robot to move slowly or
quickly? Just like you experienced in this activity, it is also helpful for the rover to
go slowly to collect lots of information for scientists studying the Red Planet.
Page 70 of 104
Activity Preparation
Tips:
Copy the worksheet
for this activity and
distribute it after the
demonstration of the
activity. While the
worksheet can be
done in class, it can
also be sent home
with students for
homework and to test
retention of material.
Classroom Instructional Strategies
Building and Programming the Rover
[NOTE: While these instructions are numbered, students can write their program
and build their rovers in any order.]
1. Have students build a basic rover in their groups. Refer to rover instructions
from Activity #3 for guidance on basic structure of the rover. Students will be
adding a light sensor using the numbered ports to the front of their rovers.
Light sensors should be pointing towards the floor to best perceive light
differential. A sample rover with a light sensor is pictured below:
If there are a limited
number of laptops for
groups to share,
assign groups to
either be builders or
programmers first.
Have groups start at
their assigned
stations and switch
once they are
completed. This will
help you avoid long
delays as students
work at computers.
2. Have students write the code that would tell the rover to drive forward and stop
when it perceives less light, then steer the rover to back up. Put these actions
in a loop to have the rover continue exploring without “falling in the craters.”
Sample Code:
Page 71 of 104
Troubleshooting
Tips:
Problem: Rover falls
off the table.
Solution: There are
many reasons a Rover
may fall off the table.
The closer the sensor
is to the body of the
Rover, the less time
there is between when
a Rover detects the
edge and when it
stops. This can be
addressed by making
the Rover go slower, or
by moving the sensor
further away from the
Rover. The Rover may
also fall off the table
while turning, or if it
approaches the edge
at a shallow angle.
Keeping the sensor
closer to the Rover
body lessens the
chances of this
happening.
If the light sensor value
that distinguishes
between the
brightness of the table
versus the floor is not
set properly, the “wait
until” block will not be
triggered. As in the
previous activity, this
can be set by trial and
error, or by reading
the sensor values from
the NXT screen to
determine an
appropriate value.
This program tells the rover to:
 Turn on motors C and B in the forward direction for an unlimited duration.
 Wait until the light sensor detects less light reflecting back from the table
(i.e. when it is hanging over the edge of the table). Change the sensor to wait
until a darker light value (‘<’ symbol).
 Then change the C and B motors in the following ways:
o Go in the backwards direction.
o Use the steering slider to make it turn while going backwards.
 For a short duration (e.g. 5 rotations or 2 seconds).
 Loop back to the beginning of the program.
Testing the Rovers
1. Groups should set their rovers on tables or desks, where the rover will have
space to move. Students should turn their run their programs and make
observations on their worksheets. Work with groups to troubleshoot as
necessary.
2. If you have time, give students time to modify their design or their program to
make it more effective at staying out of the “crater.” This may include adjusting
the sensor’s position or refining the program by changing the values.
Discussion and Observations
 What determines how far out in front the light sensor needs to be from the
rover? In the time it takes for the light sensor to react, faster rovers will travel a
greater distance. So, the light sensor needs to be further out on faster rovers.
 Could you accomplish this same goal using a distance sensor? Yes, build the
rover so that the distance sensor is pointed down. The distance sensor measures
a greater distance to the next object when it is over the edge of the table.
 Did your rover ever fall off the table? Why? Falls off edge while turning; Bad
light sensor reading, so the rover kept driving off the edge; Rover is too fast or
the light sensor is too close to the rover.
 How could you increase the chance that the rover will stay on the table? Slow it
down; add a second light sensor (one on each of the front corners of the rover).
 How long will this rover keep roaming? This program will keep looping infinitely.
So, the rover will roam until it runs out of battery or until it falls off the table.
Page 72 of 104
Optional Activity Variations
Challenge students to build a rover that uses an ultrasonic distance sensor instead of a light sensor to stay on the
table. First, groups must replace the light sensor with the ultrasonic distance sensor on their rovers. The distance
sensor should be facing down towards the table. Students can use a similar code to the one used in this activity.
Groups should change the middle icon from “wait for less light” to “wait for more distance.” This will allow the
rover to move on the table until it comes to the edge of the table, where the distance sensor will read a larger
distance towards the floor, trigger the rover to back up and loop the program.
For Further Discussion
 Why does Mars have more craters than Earth? Meteors, asteroids, or comets hitting the surface of a planet
form impact craters. As a meteor travels through a planet’s atmosphere, the meteor heats up due to friction.
Earth has more gravitational pull than Mars, which causes meteors to speed up more and heat up more while
traveling through the Earth’s atmosphere. Many meteors speed up so much while traveling through the Earth’s
atmosphere that they burn up before they hit the surface (which is what we call a shooting star). Also, erosion
and plate tectonics change the surface of the Earth and have left few craters on the Earth’s surface.
Carnegie Magazine provides information about Mars and how craters form in a way that is easy for students to
understand. They also have fun activities, such as making your own Martian soil or your own craters.
Link: http://bit.ly/kzfist
Page 73 of 104
Name: _____________________
Don't Fall in the Crater
Today we will be building and programming a rover that drives around near the edge of a crater
without ever falling in.
Answer the questions below before starting on the activity.
1. On Mars, why would it be important for the rovers to avoid falling into craters?
2. What type of sensor could you use to help a rover from falling into a crater?
Design, build, and program a rover that will drive around on the top of a table and never fall off.
After the rover has been thoroughly tested answer the questions below.
3. Did the rover ever fall off the table? Why or why not?
4. How could you increase the chance that the rover will stay on the table?
Page 74 of 104
Activity #9:
Crater Rim Exploration
In this lesson, students will engineer a rover that drives along, following the edge of a crater (a guideline made out
of black electrical tape). Students will draw connections between the rover model and the actual Mars Rovers,
which must carefully navigate the terrain of Mars to collect data about the Red Planet. In this activity, students will
use a light sensor and NXT programming to help their rovers determine the edges of “craters” and demonstrate
precision in navigation.
This activity will build on the previous activity in which students added basic programming for a sensor so their NXTprogrammed rovers could respond to external stimuli. This activity will include a programming loop and potentially
could run indefinitely.
In addition to programming and engineering experience, students will gain a better understanding of how the Mars
Rover functions autonomously on the terrain of Mars. Students will experience how scientists iteratively build on
their designs to make the most effective models.
Learning Goals
Washington State EALRs Addressed in this Activity
Students will understand the basics of NXT
programming, which allows the technological
instrument (the “brick”) to respond to external
stimuli and complete students’ designs.
Students will design and build their own rover as
before and will learn how to incorporate a light
sensor that will determine the edges of the
line/”crater.”
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
Students will draw connections between the
asteroids that struck and cratered Mars and those
that shaped Earth’s terrain.
6-8 ES3D Earth has been shaped by many natural
catastrophes, including earthquakes, volcanic eruptions,
glaciers, floods, storms, tsunami, and the impacts of
asteroids.
Students will consider the obstacles faced by the
Mars Rover and consider similarities and
differences between the terrain of Earth and Mars.
They will specifically consider the danger of uneven
terrain for an autonomous robot on this planet.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
Page 75 of 104
Reviewing Prior
Knowledge
In prior grades
students:
 Learned to work
individually and
collaboratively to
produce a product
of their own
design.
 Learned to plan
investigations to
match a given
research question.
Vocabulary
 NXT
 “Brick”
 Sensors
Materials
 LEGO® kits (1 per
group of 2-4
students)
 Worksheets
(included in this
guide)
 Overhead device
(for projecting NXT
program for class
observation)
 Electrical tape or
construction paper
Before the Activity:
Teacher Preparations:
Kits and computers should be prepared before class begins. This includes loading the
NXT program on laptops prior to class beginning, charging batteries for NXT bricks,
and making sure each kit has parts necessary for the day’s activity.
For each group, create a round crater shape with gentle curves on a table or the floor
with black electrical tape. You can also use paper if you don’t have tape. It is best to
use tape or paper that has a high contrast to your floor or table, such as black
electrical tape on a light colored floor or white paper on a dark floor.
Resources for Educators:
Video: “Exploring Erebus Rim”
Link: http://1.usa.gov/X1BDS1
This video, located between the middle and the bottom of the page, shows an
exploration of the rims of one of the craters on Mars.
Photo Gallery: “New Views of Endeavor Crater”
Link: http://bit.ly/c0QUSG
The photo gallery here will familiarize your class with the craters of Mars and the
sharp edges of craters the rovers have to navigate and avoid.
News Article: “Mars Rover Examines Odd Material at Small, Young Crater”
Link: http://bit.ly/cLDv73
This article shows pictures taken by the rover of the terrain at the rim of craters and
explains how the rover collects and helps scientists examine these finds.
Article: “Keeping the rover right side up and balanced”
Link: http://bit.ly/asd28L
Article: “Understanding which direction the rover is facing”
Link: http://bit.ly/algQ19
These two articles will be helpful if students ask how the rover knows to keep
balanced and facing the right direction, as this is essentially what students will be
doing with this activity.
Fun Resources for Students:
Video: “Retracing a Rovers Steps Out of Victoria Crater”
Link: http://bit.ly/cIQF1u
Game: “Be a Martian”
Link: http://bit.ly/d2RAUf
Page 76 of 104
Robotics Theory:
Engagement Activities
The rover starts with
its light sensor on one
side of the tape and
drives towards the
tape until it has
crossed the near edge.
The rover detects that
it has crossed onto the
tape when the light
sensor picks up a
darker value. When it
detects that it has
driven across the edge
of the tape, it changes
directions until it picks
up the different light
value of the table. The
rover drives in this
zigzag pattern along
the edge of the tape.
Discussion: Although the crater may be too steep to go into, it may be interesting to
drive around the crater to take samples of the edge. Scientists want to gather all the
information they can about Mars and its craters to find out more about the geology
of the planet. Even though scientists have never actually seen a crater being formed
on Mars, how do scientists hypothesize that asteroids and comets form these
craters? Because scientists have seen very small asteroids make impacts on Earth and
have observed parts of a comet strike Jupiter. They make educated hypotheses that
these kinds of impacts made the craters on Mars.
Navigation Exploration:
1. Have students pair up, and lead them to a hallway or other location with open
wall space. A few corners or turns will be useful as obstacles for students.
2. Blindfold one student from each pair.
3. Have the blindfolded students navigate around the space, only by feeling the
walls. The other student from each pair should make sure his or her partner stays
safe while blindfolded.
4. After a few minutes, have students switch blindfolds with their partners. Let the
newly blindfolded students navigate around the space.
 Was it easy to identify the objects you came across while blindfolded? Doors,
lockers, corners?
 Was it easier to navigate while walking slower or faster?
In this activity, we will build on the theory from the last activity, which used the light
sensor to perceive the “edge of the crater” (the black electrical tape).
 To program a robot to explore the edge of crater, just like you explored the
edges of the hallway, would you want your robot to drive slowly or fast? What
might happen if a rover drove too fast while exploring the edge of a crater? We
will want our rover to drive slowly around the crater. We will drive forward until
we see the “edge of the crater,” then turn away from the edge. Once we see “real
dirt” again, we’ll drive forward again and repeat. Since the rover only knows if
the light sensor is on or off of the edge, we have to be careful not to move too
quickly or it may not be able to stop before it falls into the crater.
Page 77 of 104
Activity Preparation
Tips:
Copy the worksheet
for this activity and
distribute it after the
demonstration of the
activity. While the
worksheet can be
done in class, it can
also be sent home with
students for
homework and to test
retention of material.
Classroom Instructional Strategies
Building and Programming the Rover
[NOTE: While these instructions are numbered, students can write their program and
build their rovers in any order.]
1. Have students build a basic rover in their groups. Refer to rover instructions from
Activity #3 for guidance on basic structure of the rover. Students will be adding a
light sensor using the numbered ports to the front of their rovers. Light sensors
should be pointing towards the floor to best perceive light differential between
the floor and electrical tape. A sample rover with a light sensor is pictured below:
If there are a limited
number of laptops for
groups to share, assign
groups to either be
builders or
programmers first.
Have groups start at
their assigned stations
and switch once they
are completed. This
will help you avoid
long delays as students
work at computers.
Programming Tip:
The rover starts with
the light sensor over
the table or floor with
the darker tape to the
left of it. Other
configurations will
work, but the students
will need to know
what it is before
programming.
2. Have students write the code that would tell the rover to turn and stop when it
senses less light (the tape or “the edge of the crater”). Then, tell the rover to
turn the other way and stop when it senses more light (the table or “regular
terrain”). Loop these actions to continue exploring the edge of the crater.
Sample Code:
This program tells the rover to:
 Turn on motor B in the forward direction for an unlimited duration.
o This turns the rover to the left, causing the light sensor to swing towards
the dark tape.
Page 78 of 104
Troubleshooting
Tips:
As in previous
exercises, determining
the sensor value that
separates the black
tape from the light
colored floor takes
some experimentation.
A higher contrast
between the color of
the floor and the tape
makes this easier. A
slower Rover is less
likely to miss the tape.
The sharper the angle
in the rim of the
crater, the easier it is
for the Rover to lose
track of the tape.
Making a short Rover
or avoiding sharp
edges in the crater rim
can alleviate this.






o Don’t go too fast – use the power slider to slow the rover down a little.
This will make for more consistent edge following.
Wait until the light sensor detects less light reflecting back (i.e. when it is
over the dark tape). Change the sensor to wait until a darker light value (‘<’
symbol).
Stop motor B.
Turn on motor C in the forward direction for an unlimited duration.
o This turns the rover to the right, causing the light sensor to swing away
from the tape, towards the lighter table/floor.
Wait until the light sensor detects more light reflecting back (i.e. when it is
over the lighter table/floor). Change the sensor to wait until a brighter light
value (‘>’ symbol).
Stop motor C.
Loop back to the beginning of the program.
Testing the Rovers
1. Groups should set their rovers next to the “crater’s edge.” Students should run
their programs and make observations on their worksheets. Work with groups to
troubleshoot as necessary.
2. If you have time, give students time to modify their design or their program to
make it more effective at staying out of the “crater.” This may include adjusting
the sensor’s position or refining the program by changing the light sensor’s
values.
Discussion and Observations
 Did your rover ever lose track of the edge of the tape? Why or why not? There
are many reasons for inaccurate sensor readings, such as dust, greasy floor,
reflection of lights, etc. Tight corners are hard to go around and could cause the
rover to lose the edge of the crater.
 How could you build a rover that is more accurate and less likely to get
knocked off course? Use two light sensors, one on each front corner of the rover.
Slow the rover down so that it has more time to detect changes in the light values
(the edge of the tape).
 Now that you can build a rover that explores the rim of a crater, what kind of
functions/tests would you want it to perform along the way? Answers may
include: take photos, identify materials in rocks or soil, or check for water (which
we’ll talk about in the next activity).
Page 79 of 104
Optional Activity Variations
Put down an electrical tape boundary in the shape of a square (4 feet by 4 feet). Have students program a rover
with a light sensor that stays within the square and doesn’t cross the tape.
The code is similar to Activity #8; the difference is that the robot here is placed inside the “crater,” or boundaries,
rather than avoiding the craters like the previous activity. This would be a good review for the concepts of that
lesson and to demonstrate to students that the same code can be used for more than one purpose.
For Further Discussion
As scientists explore more of Mars, they have begun to name the craters on Mars. Some are named after famous
scientists or science-fiction writers, and some are even named after towns on Earth. There are two craters on Mars
that have names for towns in Washington State: Yakima and Wallula. Is it important to name craters on Mars?
What would you name a crater if you had the chance?
Page 80 of 104
Name: ______________________
Crater Rim Exploration
Today we will be building and programming a rover that drives along following a piece of black
electrical tape. A successful rover will always stay very close to the tape.
Answer the question below in complete sentences.
1. What method do you plan to use to program your rover to stay near the black electrical tape?
Explain in detail.
Design, build, and program a rover that will drive along a piece of black electrical tape. After the
rover has been thoroughly tested, answer the questions below.
3. Did your rover ever lose track of the tape? Why or why not?
4. How could you build a rover that is more likely to stay on course?
5. Why would it be important for rovers on Mars to be able to follow a marked path?
Page 81 of 104
Activity #10:
Find Water on Mars
In this lesson, students will use engineer a rover capable of measuring how many deposits of water there are on an
unknown Martian landscape. Students will draw connections between the rover model and the actual Mars Rovers,
which must carefully navigate the terrain on Mars to collect data about water deposits and the possibility of
sustaining life on the planet. In this activity, students will use a light sensor and NXT programming to help their
rovers determine the location of “water deposits.”
This activity will build on the previous activity in which students added basic programming for a sensor so their NXTprogrammed rovers could respond to external stimuli. This activity will include a programming loop, and
potentially could run indefinitely.
Learning Goals
Washington State EALRs Addressed in this Activity
Students will understand the basics of NXT
programming, which allows the technological
instrument (the “brick”) to respond to external
stimuli and complete students’ designs.
Students will design and build their own rover as
before, and will learn how to incorporate a light
sensor that will determine how to isolate
specifically sought objects.
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
6-8 APPC Science and technology are interdependent.
Science drives technology by demanding better instruments
and suggesting ideas for new designs. Technology drives
science by providing instruments and research methods.
Students will consider the obstacles faced by the
Mars Rover and consider similarities and
differences between the terrain on Earth and Mars.
They will specifically consider the possible
similarities between the two that would sustain life
on another planet.
6-8 ES1B Earth is the third planet from the sun in a system
that includes the Moon, the Sun, seven other major planets
and their moons, and smaller objects such as asteroids,
plutoids, and comets. These bodies differ in many
characteristics (e.g., size, composition, relative position).
Page 82 of 104
Reviewing Prior
Knowledge
In prior grades
students:
 Learned to work
individually and
collaboratively to
produce a product
of their own
design.
 Learned to plan
investigations to
match a given
research question.
Vocabulary
 Water deposits
 Hematite
 Test run
Materials
 LEGO® kits (1 per
group of 2-4
students)
 Worksheets
(included in this
guide)
 Overhead device
(for projecting NXT
program for class
observation)
 Tape
Before the Activity:
Teacher Preparations:
Kits and computers should be prepared before class begins. This includes loading
the NXT program on laptops prior to class beginning, charging batteries for NXT
bricks, and making sure each kit has parts necessary for the day’s activity.
Put 4-8 strips of electrical tape on the floor, spaced at least a few inches apart. For
extra fun, put the strips of tape under a table and hang cloth around the edges of
the table. The students won’t be able see how many water deposits there are, and
will have to wait for communication from the rover to find out. Make sure there is a
high contrast between the tape and the floor.
Resources for Educators:
Video: “PBS NOVA: Is There Life on Mars”
Link: http://to.pbs.org/9zG7Yz
This 50-minute video can be divided over a series of classes; the website has the
video divided into six parts that can either be introductions to a series of classes or
can be used individually for different topics. Chapter 2 discusses water on Mars.
Article: “NASA Images Suggest Water Still Flows in Brief Spurts on Mars”
Link: http://bit.ly/acdsE2
This article offers more information on water on Mars then and now.
Fun Resources for Students:
Interactive Website: “Where Do You Find Water on Mars”
Link: http://bit.ly/9lPSPr
Page 83 of 104
Astronomy Theory:
Although there are
currently no liquid
bodies of water on the
surface of Mars, one of
the main objectives of
sending rovers to Mars
was to see if there was
evidence of liquid
water on its surface in
the past. The rovers
have discovered many
pieces of evidence
(and they have even
found ice made of
water). Certain types
of minerals, such as
hematite, only form in
the presence of water.
Engagement Activities
1. Activity: http://bit.ly/bIxjbf This activity prompts students to examine sand from
a variety of locations (which can be brought from home or collected at school) to
help students formulate a reasonable history of that terrain. Engagement
questions for this activity are included on the website. Note: this activity may
take longer than one class.
2. Activity: http://bit.ly/a5uHGx This activity helps students understand how
flowing water can shape terrain, and will begin discussions about how both Earth
and Mars’s surfaces were affected by water. Note: suggested class time for this
activity is 2-3 classes.
3. Discussion: Why would scientists want to look for water on Mars? Scientists
believe that life needs water to survive. Finding water might mean that Mars
could support life, so this would be a very exciting discovery, indeed!
Additionally, NASA
scientists have found
high concentrations of
salts, which are
thought to have
formed when the
water they were
dissolved in nowevaporated water. The
real rovers use
sophisticated sensors
to determine what
materials are present
in the rocks on Mars.
In this exercise, finding
the black tape with the
light sensor is like
finding hematite or
high concentrations of
salts. The existence of
past water on the
surface of Mars means
that life may have
once been possible on
Mars. It also suggests
that many exo-planets,
planets outside our
solar system, may also
be capable of hosting
life.
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Activity Preparation
Tips:
Copy the worksheet
for this activity and
distribute it after the
demonstration of the
activity. While the
worksheet can be
done in class, it can
also be sent home with
students for
homework and to test
retention of material.
Classroom Instructional Strategies
Building and Programming the Rover
[NOTE: While these instructions are numbered, students can write their program and
build their rovers in any order.]
1. Have students build a basic rover in their groups. Refer to rover instructions from
Activity #3 for guidance on basic structure of the rover. Students will be adding a
light sensor using the numbered ports to the front of their rovers. Light sensors
should be pointing towards the floor to best perceive light differential. A sample
rover with a light sensor is pictured with an example of the “water deposits” on
Mars’ terrain:
If there are a limited
number of laptops for
groups to share, assign
groups to either be
builders or
programmers first.
Have groups start at
their assigned stations
and switch once they
are completed. This
will help you avoid
long delays as students
work at computers.
2. Have students write the code that would tell the rover to drive forward,
perceive “water” (in the form of a dark line here) and signal its presence with a
beep before continuing to search.
Sample Code:
This program tells the rover to:
 Turn on motors C and B in the forward direction for an unlimited duration.
o Don’t go too fast—use the power slider to slow the rover down a little.
This will make for more consistent light readings.
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Troubleshooting
Tips:
The rover must be able
to complete its sound
before it reaches the
next strip of tape. The
rover should travel
slowly and play a short
sound.
As with previous
activities, determining
the sensor value that
distinguishes between
the tape and the floor
requires
experimentation or
reading the values
from the NXT screen.
 Wait until the light sensor detects less light reflecting back from the surface
(i.e. when it is over the dark tape). Change the sensor to wait until a darker
light value (‘<’ symbol).
 Play a sound. You can select a sound file or a tone, but the sound should be
short so that the rover doesn’t miss the next line of tape.
 Loop back to waiting for the dark tape.
Testing the Rovers
1. Groups should set their rovers near the strips (or in front of the curtain, if the
strips are hidden). Students should run their programs and make observations
about performance and collected data (in the form of beeps) on their
worksheets. Work with groups to troubleshoot as necessary.
2. If you have time, give students time to modify their design or their program to
make it more effective at finding water. This may include adjusting the sensor’s
position or refining the program by shortening the beeps or changing the values.
Discussion and Observations
 How would you check to see if your rover is measuring the correct number of
water deposits (since you can’t go to Mars and see yourself)? Set up a test run,
where you put a known number of strips on the floor and run your rover over
them, watching to make sure the rover beeps for every strip. Researchers test
their robots using trial runs before sending them to Mars. Common Mars Rover
testing grounds include Antarctica and deserts in Chile and the southwest US.
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Optional Activity Variations
Setting Alerts
We can have the rover alert us if something interesting happens. In this case, if we find a strip of tape (water), we
will sound the alarm notifying us that the rover has done its job. This way we don’t have to closely watch all the
sensor reading, which would be boring, we can just have the robot alert us when it thinks it has found something
interesting. Challenge student to program their rover to make a certain noise when it is driving along (to simulate
non-interesting sensor info) and make a distinct noise when it find “a water deposit.”
For Further Discussion
 Can Mars sustain life? All forms of life on Earth need water to sustain them. Even if Mars had or has water, it
also lacks an atmosphere like Earth’s. Check out information on this mission to Mars that will explore the upper
atmosphere of Mars: http://www.nasa.gov/mission_pages/maven/main/index.html. It is scheduled to launch in
late 2013 and would give us a better understanding of the atmosphere of Mars and if it ever was able to sustain
life like Earth.
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Name: _______________________
Find Water on Mars
Today we will be learning more about Mars and one of the important reasons we have sent rovers
there. We will be building and programming a rover that searches for water sources (represented by
black electrical tape).
Please answer the questions below before working on your rover.
1. What evidence have the rovers on Mars found that prove there was once water on Mars? Explain
in detail.
Design, build and program a rover that will be able to detect and accurately count the number of
water sources (black electrical tape) present.
Record the results of 5 passes under the table below.
Pass #
1
2
3
4
5
Water Sources Found
Answer the questions below in complete sentences.
2. Was the number of water sources found the same for reach run? Why or why not?
3. Before sending a rover to Mars, how could you be sure that it would count the correct number of
water resources each time?
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Mars Rover Unit Three Overview:
For this final multi-day activity, students will synthesize the knowledge they gained from earlier activities. Students
will study a racecourse that has been pre-designed by the teacher. Then students will have to design, engineer and
program a vehicle that drives through this unknown landscape.
The lessons of this unit can be used in isolation, or as a group.
Grade level: 6-8
Group size: 2-4
LEGO® Materials needed: LEGO® MINDSTORMS® NXT 2.0 Set with corresponding MINDSTORMS® software
Contents:
Page 91
Activity #11: Mars Rover Race
Learning Objectives for All Lessons:
 Working in groups, students will design and build their own rover and will compare designs to determine which
model is fastest and travels most accurately through obstacles.
 Students will run several trials and collect data to accurately assess the validity of their design.
Educational Standards Addressed:
National Standards: Science
NS.5-8.1 SCIENCE AS INQUIRY
As a result of activities in grades 5-8, all students should develop:
 Abilities necessary to do scientific inquiry
 Understanding about scientific inquiry
NS.5-8.2 PHYSICAL SCIENCE STANDARDS
As a result of their activities in grades 5-8, all students should develop an understanding of:
 Motions and Forces
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NS.5-8.5 SCIENCE AND TECHNOLOGY STANDARDS
As a result of their activities in grades 5-8, all students should develop:
 Abilities of technological design
 Understanding of science and technology
Washington State Standards: Science
6-8 INQ SCIENCE AS INQUIRY
As a result of activities, students will learn that:
 6-8 INQC Collecting, analyzing, and displaying data are essential aspects of all investigations.
6-8 APP SCIENCE, TECHNOLOGY AND PROBLEM SOLVING
As a result of activities, students will learn that:
 6-8 APPD The process of technological design begins by defining a problem and identifying criteria for a
successful solution, followed by research to better understand the problem and brainstorming to arrive at
potential solutions.
 6-8 APPE Scientists and engineers often work together to generate creative solutions to problems and decide
which ones are most promising.
 6-8 APPF Solutions must be tested to determine whether or not they will solve the problem. Results are used to
modify the design, and the best solution must be communicated persuasively.
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Activity #11:
Mars Rover Race
In this multi-day activity, students will iteratively design and construct a Mars rover that can successfully navigate a
Martian racecourse the fastest. This multi-day activity is a competition to design the fastest rover for searching
Mars. Students will program a rover to navigate a simple racecourse, optimizing their route through the course (i.e.
driving algorithm) to be the fastest. Then they will design a second program to solve an entirely new racecourse
layout. The times needed to complete the two courses will be added to determine a winner.
Learning Goals
Working in groups, students will design and build
their own rover and will compare designs to
determine which model is fastest and travels most
accurately through obstacles.
Students will run several trials and collect data to
accurately assess the validity of their design.
Washington State EALRs Addressed in this Activity
6-8 APPD The process of technological design begins by
defining a problem and identifying criteria for a successful
solution, followed by research to better understand the
problem and brainstorming to arrive at potential solutions.
6-8 APPE Scientists and engineers often work together to
generate creative solutions to problems and decide which
ones are most promising.
6-8 APPF Solutions must be tested to determine whether or
not they will solve the problem. Results are used to modify
the design, and the best solution must be communicated
persuasively.
6-8 INQC —Investigate— Collecting, analyzing, and
displaying data are essential aspects of all investigations.
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Reviewing Prior
Knowledge
In prior grades
students:
 Learned to work
individually and
collaboratively to
produce a product
of their own
design.
 Learned to plan
investigations to
match a given
research question.
Vocabulary
 NXT
 “Brick”
 Sensors
Materials
 LEGO® kits (1 per
group of 2-4
students)
 Worksheets
(included in this
guide)
 Overhead device
(for projecting NXT
program for class
observation)
 Objects for 3 gates
in racecourse
 Stopwatch
 Tape
Before the Activity:
Teacher Preparations:
Three sets of gates will need to be collected. They can be anything from matching
soda cans to pairs of books, hats, shoes, etc. It’s helpful to keep the two objects
marking the gate the same, i.e. two soda cans for Gate 1, two bottles for Gate 2,
two matching shoes for Gate 3, etc. A stopwatch for timing the rovers will also be
needed. Tape can be used to mark the Start/Finish line.
It is important for teachers to keep the racecourse obstacles in the same places over
the course of this activity. Teacher can simply leave the gates in their positions if
they don’t disturb the classroom or gates can be removed with their placement
marked by tape on the floor.
Resources for Educators:
Article: “Mars Rover Sets Endurance Record”
Link: http://bit.ly/10njHjs
This article offers information on longevity and endurance of the original Mars
Rovers, Spirit and Opportunity.
Article: “Traverse Far and Well”
Link: http://bit.ly/9DbMHF
This article is the final in the series of articles throughout this guide referring to the
function and structure of the Mars Rover. This one specifically applies to this lesson,
as it deals with longevity and accuracy of travel.
Activities: “The Red Album”
Link: http://bit.ly/9y76Pi
These activities prompt students to continue their education about the space
program and Mars exploration in particular, and ask students to research or write to
politicians with their educated views on space exploration. This would be an
appropriate summative activity to tie together many of the threads introduced in
this guide.
Fun Resources for Students:
Interactive Website: “Meet the Rover Team”
Link: http://bit.ly/9Ylu1R
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Tips and Tricks:
Engagement Activities
Students can act out
this activity if your
school has a large
enough open space.
Divide the class into
two. Each team will
create a course that
another student must
walk through. Each
course will consist of a
starting line, a finish
line and four “gates,”
two students facing
each other with their
hands touching over
their heads. Groups
should try to create a
course that will take
the longest to walk
through. Gates can be
walked through in any
order and from either
side. Pick one student
to walk through both
the courses. Have
group members set-up
their gates and time
how long it takes the
student to walk
through each course. If
time permits, allow
other students to pass
through the course.
Make your own Maze:
1. Pass out graph paper to students.
2. Have students color with highlighters any four squares of the graph paper that
they would like.
3. Collect the papers, shuffle them, and pass them back randomly to students.
4. Tell students that they must use the graph paper as a maze while passing
through each of the four highlighted boxes. They can travel diagonally through
boxes as well as side to side. Have all students orient their papers lengthwise;
they should start at the left and finish at the right of the paper. Advise students
that they should find the shortest distance from start to finish while passing
through the colored boxes.
 Which mazes took the shortest distance to complete? Why?
 Which mazes took the longest distance to complete? Why?
 Was it more efficient to travel straight or diagonally across the graph paper?
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Activity Preparation
Tips:
Copy the worksheet
for this activity and
distribute it after the
demonstration of the
activity. While the
worksheet can be
done in class, it can
also be sent home
with students for
homework and to test
retention of material.
If there are a limited
number of laptops for
groups to share,
assign groups to
either be builders or
programmers first.
Have groups start at
their assigned
stations and switch
once they are
completed. This will
help you avoid long
delays as students
work at computers.
Classroom Instructional Strategies
Designing, Testing and Building Racers
According to the rules below, groups should construct racers capable of navigating a
course the fastest. Students may use sensors and may modify the basic rover
model.
Rules:
 The course is composed of three gates and a finish line.
o The gates should be about 2 feet apart and randomly placed on the
classroom floor.
o The placement of the gates needs to be determined before the students
start programming.
 The rover must pass through each set of gates and then cross the finish line.
 The students can design their own route and instruct the rover to pass through
the gates in any order.
o Part of the challenge is picking the fastest route through the gates (i.e.
driving algorithm). There will always be fast algorithms through the course
and slow ones, based on how the gates are distributed across the floor.
 A rover can pass completely through a gate, and then back out of the gate. It
does not have to continue forward.
 One rover at a time will navigate the course to accurately measure the time it
takes.
Suggested schedule:
Note: Hold fewer or more rounds of different racecourses depending on the
number of days available for the final activity.
 Day 1:
o Build a simple rover.
o Start designing and programming the driving algorithm (i.e. the route for
the rover).
 Encourage the students to test out their program on the course as
they’re designing it.
 Day 2:
o Finish the program, continuing to test the rover on the course.
o Run the racecourse a few times for each rover. Record the best time for
each rover.
o Have the students write a summary of the results for their rover and
algorithm (design of route through the gates, description of rover
construction, any other iterations tried and lessons learned, etc.).
 Day 3: With a new racecourse (gates randomly redistributed), design a new
algorithm for the course.
Page 94 of 104
Troubleshooting
Tips:
This is an activity of
precision in coding and
iterative design.
Groups will have to
create code unlike any
other activity in this
guide. Students may
get frustrated if their
code does not
immediately get their
rovers through the
gates. Remind
students that this will
take many trials and
adjustments to perfect
their code.
 Day 4: Tally up scores (add the best times from each race course for each
group). Analyze different groups’ algorithms and who had the fastest rover and
why.
Discussion and Observations
 What makes the fastest team’s rover win?
o Is it the distance it covers?
o Or the speed it travels?
o Or the path they chose through the gates?
o Did their rover travel in straight lines? Or curved lines?
o How did the winning rover turn corners? How many turns did they make?
Page 95 of 104
Optional Activity Variations
After all groups complete at least one racecourse with three gates, create a more difficult course for the rovers.
This new racecourse should have gates to pass through and other obstacles, such as playing a sound when it
approaches a certain obstacle, driving in a circle around an object, or passing through all the obstacles and
returning to the original starting line.
For Further Discussion
These are all factors the NASA scientists and engineers take into account when planning the design of the Mars
Rover (how fast it should go, how it should turn) and when planning the navigation route on Mars (what series of
geologic features to visit on the planet’s surface). Check out what the rover Curiosity looks like here:
http://www.nasa.gov/mission_pages/msl/multimedia/pia15181.html
Page 96 of 104
Mars Rover Robotics Curriculum Guide Post-Test
Name:
Please circle one:
Girl
Boy
1. Which statement best describes your feelings about science:
a) I like science class, but I like other subjects more
b) Science is difficult for me but I like science class
c) I go to science class because I have to
d) I love science class!
e) I like doing science, but I prefer it outside of class
2. What is your favorite part of science class?
3. Which statement best describes your feelings about careers in the science, technology, engineering,
or mathematics fields:
a) I like one or more of these fields, but I don’t know a lot about careers in those fields
b) I’m not interested in getting a career in those fields
c) I imagine myself pursuing a career in one or more of those fields
d) I like those fields, but I’m unsure if I want a career in them
4. Describe a robot you made during class. Explain in your own words how you created it.
5. If you could build a robot to help you or someone you know, what would it do and how would it
function?
Page 97 of 104
Technically Learning’s Glossary of terms
for LEGO® NXT Kits and Software
All appropriate names are listed next to each item.
NXT Brick
Rechargeable Battery
Motor
Page 98 of 104
Ports
Touch Sensor
Sound Sensor
Light Sensor
Page 99 of 104
Ultrasonic Sensor,
Ultrasonic Distance Sensor
Cables
Page 100 of 104
USB Cable
Lamp and
Connector Cable
Shortcut to
LEGO®MINDSTORMS® Programming Software
Page 101 of 104
MINDSTORMS® Software Canvas
"Move" Icon
"Record/Play" Icon
"Sound" Icon
Page 102 of 104
"Display" Icon
"Wait" Icon
"Loop" Icon
"Switch" Icon
Download Button
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Button for Complete Palette
Button for Common Palette
Pegs
H Connector
Axles
Gear
Page 104 of 104