Proposal
GanymedeOrbiterandLanderMission
Fall2012
COASTER-G
Coasting by, setting our lasers to stun!
Sparkman High School Team 1
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Proposal
GanymedeOrbiterandLanderMission
Fall2012
We are a team from Sparkman High School participating in the INSPIRESS Program with UAH.
Our team name is COASTER-G; it stands for CruisingOrbiter Analyzing Surface Tidal Elasticity of the
Regolith ofGanymede. We are designing a payload to retrieve information for NASA about Ganymede.
We decided to measure the tidal flexing of Ganymede, which is the contracting and expanding of the
regolith (surface material). We want to know more about its surface and the effects of Jupiter’s gravity it
has on it. Our science objective is to measure the changes in height of the surface of Ganymede. We will
orbit this Jovian satellite for one week, creating a 3-D map of the surface. It will be orbiting Ganymede at
40,000 meters. Table 1. Science Traceability Matrix
Science Objective
Measurement
Objective
Measurement
Requirement
Instrument selected
Tidal Flexing
Measure ΔAltitude
week
3D Mapping
3D model of
Ganymede
Determine the volume
of material displaced
by tidal flexing
week
Laser Altimeter
Accelerometer
Laser Altimeter
week
Laser Altimeter
Internal Structure
Our group is going to implement the use of a Laser Altimeter. We will be using two Newcon
Optik altimeters to gather our information from the planet. This instrument can work at 40,000meters in
vacuum and it produces a single laser beam reflected at the surface back into receivers on the payload.
Each of these altimeters sends beam pulses at 1000 Hz. We will be using three lithium batteries to power
our payload primarily our laser altimeter system, which will be running continuously over the time period
of one week. After all of our calculations, our batteries will have enough power allotted for our
instruments over the week.
Table 2. Science Traceability Matrix
Instrument
Mass
Power(W)
Lifetime
Frequency
Duration
Laser
Altimeter
1.7kg
15W
1week
10 Hz
Continuous
Accelerometer
A/38
0.9g
(0.0009 kg)
1W
1 week
32/36kHz
Continuous
UHF Antenna
Ying-Hao RF
Antenna Series
1e
Lithium
Battery (3)
<10g
(0.01 kg)
1-10 W
1week
0-2400MHz
N/A
3 kg total
1200 W/Hr
total
1 week
N/A
N/A
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Proposal
GanymedeOrbiterandLanderMission
Fall2012
Our team has come up with two alternatives to our design, Jack in the Box and Deer Slug. Deer
Slug is our first alternative that uses pressure from the spacecraft to launch itself into orbit. Michael
Dynes, our chief engineer, came up with this idea. The payload is surrounded by a shell to protect it from
outside materials that could potentially collide with it while orbiting Ganymede. The Deer slug has a “no
fail” launch and a protection around it; however, it weighs more, it could have a limp antenna, it has a
slower acceleration rate, and the shell must be removed. This alternative will be launched by a Helium
Gun. It will have a laser transmitter and a receiver protected by a shell. This exterior shell will cover these
component parts protecting it from any matter that could cause damage to these instruments. It will have
a rigid antenna that will prevent from it hitting the probe. This provides more safety for the probe.
Top
Shell
Front
Receiver
Transmitter
Back
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Side
Proposal
GanymedeOrbiterandLanderMission
Fall2012
The Jack in the Box is the alternate concept that we designed that uses a spring launching system
to orbit around the satellite. Scott Windsor, one of our engineers, came up with this idea. This alternative
is designed to stay farther away from the ground so we would not have to worry about it crashing into the
ground. The Jack in the Box has a faster acceleration and a better power storage capacity; however, this
alternative goes slower in terms or orbiting, it has more mass, and it requires more pressure to be
launched from the UAH space craft. Its telescoping antenna is used as a gravity gradient on this
alternative.
Pros:
Cons:
Deer Slug
Jack in the Box
Deer Slug
Jack in the Box
Shell protects components
from environment
Telescoping antenna
(doubles as gravity
gradient)
Unreliable antenna
Less mass than Deer
Slug
Inefficient use of space
in shell
Mass exceeds constraints
Less speed than
Deer Slug(higher
orbiting altitude)
Reliable launch
Greater speed (lower
orbit altitude) than
Jack in the Box
Batterypack
Launch stabilizer
LaunchBarrel
Instrument
Housing
Unreliable launch
SideView
JackintheBoxdesigns
FrontView
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Proposal
GanymedeOrbiterandLanderMission
Fall2012
Table 4. Mass and Power Budget
Component
Number
Lithium
Battery
Laser
Altimeter
UHF Antenna
Accelerometer
3
1 kg
400W
1
1.7 kg
15 W
1.7 kg
15 W
1-10 W
<1W
<0.01 kg
0.0009
kg
1-10 W
<1W
1
1
Mass (kg)
Power (W)
<0.01 kg
0.0009 kg
Total Mass
(kg)
3 kg
Total Power
(W)
1200 W
Decision Analysis
FOM
Weight
FinalVelocity(LaserAccuracy)
PsiUsed
Mass
SureLaunch
Total
9
1
3
9
Deer
Slug
9 x9=81
1x1=1
3x3=9
9x9=81
172
Jack‐in‐the‐box
FinalDesign
3x9=27
9x1=9
9x3=27
3x9=27
90
9x9=81
3x1=3
9x3=27
9x9=81
247
The final design is a combination of both alternative designs, utilizing the best concepts from
each design. The final design uses the pressure launching system of the Deer Slug as opposed to the
spring launching system of the Jack in the Box. The final design will have a telescoping UHF antenna that
also serves as a gravity gradient. The final design will be squared off to maximize rear surface area and
therefore maximize available force from the pressurized helium. Our mission will provide data and
findings for NASA to use on future explorations. The 3D model we will obtain could be used for future
endeavors to Ganymede. With this mission we may possibly find signs of extraterrestrial life, propelling
us into a new age of man.
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