Opinions on Space Exploration
Grade 5
English Language Arts Unit
Table of Contents
Text 1:
Space Exploration is Worth the Cost
by Institute for Learning
Text 2:
Not in Our Lifetime
by Institute for Learning
Text 3:
Into Orbit: A Brief History of Space Exploration
by Aerospace Corporation
Text 4:
Timeline of Space Exploration
by Institute for Learning
Text 5:
Our Future in Space
by Peter W. Ames Research Center, NASA
Text 6:
Benefits of Space Exploration
by Tega Jessa
Text 7:
SpaceX Boldly Looks to Blast “Millions of People to
Mars”
by Miles O’Brien
Text 8:
A One-Way Ticket to Mars
by Lawrence M. Kraus
© 2013 UNIVERSITY OF PITTSBURGH
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Space Exploration is Worth the Cost
Institute for Learning
Institute for Learning. (2012). Space exploration is worth the cost.
This document may be photocopied and distributed without permission
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Space Exploration Is Worth the Cost
Institute for Learning
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Space exploration allows us to examine planets beyond earth with the possibility of finding new
life and possible new places to live. For example, the unmanned exploration of Mars by
NASA’s Curiosity Rover allows scientists to begin to explore our future in space. To further
investigate the possibility of living in space, I propose that the government increase our budget
for space exploration and that NASA begins to send humans on missions to Mars.
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The world’s population is increasing rapidly. According to Ann Hoevel, a journalist for CNN, “In
the relatively short time between 2007 and 2050, there could be roughly 2.4 billion more people
on Earth needing clean water, space and other natural resources from their environment in
order to survive” (www.cnn.com, 08/29/12). The addition of 2.4 billion people would bring the
earth’s population to 8.4 billion! With only three percent of the Earth’s water judged
consumable, meaning that it can be used for drinking, we need to find additional resources to
support our world’s population growth. Space has the potential to provide the additional
resources that may not be available on earth.
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People believe that it may be too expensive to continue to explore space. A manned space
mission to Mars would cost an estimated $50 billion. According to G. Scott Hubbard, a
professor at Stanford University, for every dollar spent on the space program, the United States
receives eight dollars of economic benefit (www.freakonomics.com, 08/29/12). So, while space
exploration may seem costly, an important factor to keep in mind is that spending money on
space actually helps the economy.
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The Mars Curiosity Rover has helped to bring back the enthusiasm for space travel. The
images sent back to NASA show that Mars has many resources that may be valuable to all of
us on Earth. Unlike a robot, an observant scientist would be able to assess the resources on
Mars. A case in point might be a geologist, a scientist that studies rocks, examining structures
on Mars in person instead of through pictures. When Neil Armstrong made his “giant leap for
mankind” on the moon, he didn’t intend for human-led space exploration to end there. Humans
must be part of future space expeditions to better assess the resources available, something
that robots are unable to do.
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Robots, such as the Curiosity Rover, provide certain benefits to space travel. They are less
expensive to send to space and they are more powerful than humans, especially when working
in microgravity, which is the weightlessness experienced in the orbit of a planet. However,
robots do not move with the speed or precision of a human, often slowed by the relay time it
takes a command to reach its operating system. Leaving space exploration solely to robots
would lead to missed opportunities for finding valuable resources.
With the increasing population and the increasing need for resources, spending more money
on space and using humans for exploration are necessary. There may come a day when
humans need to leave Earth and live in space. Without the careful exploration of the resources
available to us outside of the Earth’s atmosphere, humans may not know where to go to
continue to thrive in much the way we do on earth.
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Not in Our Lifetime
Institute for Learning
Institute for Learning. (2012). Not in Our Lifetime.
This document may be photocopied and distributed without permission
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Not in Our Lifetime
Institute for Learning
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In 2004, President George W. Bush stated, "We do not know where this journey will end,
yet we know this: human beings are headed into the cosmos"
(http://www.oecdobserver.org/, 08/30/12). With the introduction of space tourism, the costs
of space travel have reached a new high. Space tourism poses safety risks to all those
involved and will affect scientific exploration conducted by NASA.
In 2012, approximately $18.7 billion was budgeted by the government for NASA, with $4.3
billion going to the space shuttle program. This amount has decreased every year for the
last 4 years. While $4.3 billion seems like enough money to fund additional missions to
space, it is estimated that $30 billion would be needed to send humans to explore planets
such as Mars (http://www.marssociety.org, 08/30/12). Space tourism will pull even more
money away from NASA.
For instance, companies such as Virgin Galactic, a privately owned space tourism
company, charge passengers $200,000 to $1 million for the opportunity to travel to space.
Consequently, money could be drawn away from NASA to support private explorations of
space. The federal government could see this private money as a factor in reducing public
funding for the space program. Because of space tourism, NASA could be asked to use
private companies to travel to space by lowering opportunities for exploration and research.
Many credit space tourism with creating additional jobs. For example, many more space
shuttles will be needed to carry people into space and as many as 12,500 jobs have
already been created by private space travel companies as they prepare shuttles to venture
into space (www.virgingalactic.com, 08/29/12). Unfortunately, many of the individuals
working for private space travel companies do not have the needed experience to make
sure that shuttles meet the necessary safety standards and, furthermore, that launches are
conducted properly. Many employees are coming from the airline industry, which has
different standards than those set by NASA.
Risks, such as those experienced by Mike Melvill on his SpaceShipOne flight, and the
previous tragedies experienced with space shuttles such as Columbia and Challenger, will
be experienced by a larger number of people if space tourism continues to grow. For
example, roughly 400 people have already registered for a flight to space and it is
estimated that an additional 30,000 people will register in the next 10 years
(www.virgingalactic.com, 08/29/12). Should so many people be put in harm’s way just to
save a few dollars? In addition, the President has even suggested asking NASA’s scientists
to buy seats on private space flights to save money (New York Times, 09/15/10)! Should
we be putting our scientists’ lives in the hands of companies with very little space
experience?
I think we can all agree that space tourism, while appealing to people’s sense of adventure,
is a dangerous and costly idea. Although it may appear to save money, the cost in the risks
to human life and the limits it may put on scientific exploration outweigh any savings. While
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space exploration is “one giant leap for mankind”, space tourism would be a giant step
backward.
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Into Orbit: A Brief History of Space Exploration
Reprinted with permission of The Aerospace Corporation.
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Into Orbit
A Brief History of Space Exploration
The Aerospace Corporation
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Humans have dreamed about spaceflight since antiquity. The Chinese used rockets for
ceremonial and military purposes centuries ago, but only in the latter half of the 20th century
were rockets developed that were powerful enough to overcome the force of gravity to reach
orbital velocities that could open space to human exploration.
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As often happens in science, the earliest practical work on rocket engines designed for
spaceflight occurred simultaneously during the early 20th century in three countries by three
key scientists: in Russia, by Konstantin Tsiolkovski; in the United States, by Robert Goddard;
and in Germany, by Hermann Oberth.
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In the 1930s and 1940s Nazi Germany saw the possibilities of using long-distance rockets as
weapons. Late in World War II, London was attacked by 200-mile-range V-2 missiles, which
arched 60 miles high over the English Channel at more than 3,500 miles per hour.
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After World War II, the United States and the Soviet Union created their own missile programs.
On October 4, 1957, the Soviets launched the first artificial satellite, Sputnik 1, into space.
Four years later on April 12, 1961, Russian Lt. Yuri Gagarin became the first human to orbit
Earth in Vostok 1. His flight lasted 108 minutes, and Gagarin reached an altitude of 327
kilometers (about 202 miles).
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The first U.S. satellite, Explorer 1, went into orbit on January 31, 1958. In 1961 Alan Shepard
became the first American to fly into space. On February 20, 1962, John Glenn’s historic flight
made him the first American to orbit Earth.
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“Landing a man on the moon and returning him safely to Earth within a decade” was a national
goal set by President John F. Kennedy in 1961. On July 20, 1969, Astronaut Neil Armstrong
took “a giant step for mankind” as he stepped onto the moon. Six Apollo missions were made
to explore the moon between 1969 and 1972.
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During the 1960s unmanned spacecraft photographed and probed the moon before astronauts
ever landed. By the early 1970s orbiting communications and navigation satellites were in
everyday use, and the Mariner spacecraft was orbiting and mapping the surface of Mars. By
the end of the decade, the Voyager spacecraft had sent back detailed images of Jupiter and
Saturn, their rings, and their moons.
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Skylab, America’s first space station, was a human-spaceflight highlight of the 1970s, as was
the Apollo Soyuz Test Project, the world’s first internationally crewed (American and Russian)
space mission.
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In the 1980s satellite communications expanded to carry television programs, and people
were able to pick up the satellite signals on their home dish antennas. Satellites discovered an
ozone hole over Antarctica, pinpointed forest fires, and gave us photographs of the nuclear
power-plant disaster at Chernobyl in 1986.
Astronomical satellites found new stars and
gave us a new view of the center of our
galaxy.
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In April 1981 the launch of the space shuttle
Columbia ushered in a period of reliance on
the reusable shuttle for most civilian and
military space missions. Twenty-four
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successful shuttle launches fulfilled many scientific and military requirements until January
1986, when the shuttle Challenger exploded after launch, killing its crew of seven.
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Space Shuttle
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The Challenger tragedy led to a reevaluation of America’s space program. The new goal was
to make certain a suitable launch system was available when satellites were scheduled to fly.
Today this is accomplished by having more than one launch method and launch facility
available and by designing satellite systems to be compatible with more than one launch
system.
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The Gulf War proved the value of satellites in modern conflicts. During this war allied forces
were able to use their control of the “high ground” of space to achieve a decisive advantage.
Satellites were used to provide information on enemy troop formations and movements, early
warning of enemy missile attacks, and precise navigation in the featureless desert terrain. The
advantages of satellites allowed the coalition forces to quickly bring the war to a conclusion,
saving many lives.
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Space systems will continue to become more and more integral to homeland defense, weather
surveillance, communication, navigation, imaging, and remote sensing for chemicals, fires and
other disasters.
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International Space Station
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The International Space Station is a research laboratory in low Earth orbit. With many different
partners contributing to its design and construction, this high-flying laboratory has become a
symbol of cooperation in space exploration, with former competitors now working together.
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And while the space shuttle will likely continue to carry out important space missions,
particularly supporting the International Space Station, the Columbia disaster in 2003 signaled
the need to step up the development of its replacement. Future space launch systems will be
designed to reduce costs and improve dependability, safety, and reliability. In the meantime
most U.S. military and scientific satellites will be launched into orbit by a family of expendable
launch vehicles designed for a variety of missions. Other nations have their own launch
systems, and there is strong competition in the commercial launch market to develop the next
generation of launch systems.
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Timeline of Space Exploration and Events
Institute for Learning
Institute for Learning. (2012). Timeline of space exploration and events.
Copyright laws may prohibit photocopying this document without express permission.
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Timeline of Space Exploration Events
1783 – First unmanned hot air balloon launched. (France)
1903 – The Wright brothers pilot first airplane flight. (USA)
1942 – First rocket reaches space. (Germany)
1948 – First monkey in space. (USA)
1957 – (October) First satellite (Sputnik) launched. (Russia)
1957 – (November) First animal orbits earth. (Russia)
1959 – First unmanned spacecraft lands on moon. (Russia)
1961 – First man in space. (Russia)
1963 – John F. Kennedy promises to land men on moon. (USA)
1963 – First woman in space. (Russia)
1966 – Robot spacecrafts land on moon. (Russia & USA)
1969 – First men land on moon. (USA)
1970 – Apollo 13 explosion (USA)
1971 – Lunar Rover is used to explore moon. (USA)
1973 – Probe sent to Mars. (Russia)
1981 – Space Shuttle program begins. (USA)
1983 – First American woman in space. (USA)
1986 – Space Shuttle Challenger explodes. (USA)
1991 – First Briton–a woman–in space. (Great Britain)
2000 – First crew on International Space Station.
2004 – Privately funded spaceship launched. (USA)
2011 – Space Shuttle program ends. (USA)
2012 – Space capsule with male and female astronauts launched. (China)
2012 - First private company sends spacecraft to International Space Station. (USA)
2012 - Politicians, scientists, entrepreneurs, and everyday people debate both funding
for space exploration and the best methods for space exploration. (USA)
© 2013 UNIVERSITY OF PITTSBURGH
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Our Future in Space: Space Exploration and Travel
Peter W. Waller
Peter W. Waller Ames Research Center, NASA/ © 2003 Grolier
Incorporated. All Rights Reserved.
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Our Future in Space: Space Exploration and Travel
by Peter W. Waller
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Space Exploration and Travel
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For centuries, people have dreamed of leaving the Earth and traveling through space to
visit the moon and explore other planets and stars. During the past thirty years, some of
these dreams have become realities. Spacecraft have orbited the Earth and sent back data
to ground-based scientists. They have traveled to other planets and transmitted images and
information that have helped to expand our knowledge of the solar system. People have
gone into space to orbit the Earth and even to visit the moon.
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In 1992, a United States satellite, the Cosmic Background Explorer (COBE), detected slight
variations or ripples in the background microwave radiation coming from far out in space.
This information may be helpful in determining how the universe evolved.
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Despite such achievements, space exploration is still in its infancy considering the vast
scope of the universe and the many unanswered questions about it. For example, scientists
estimate that there are 10 billion stars like our sun in the Milky Way galaxy, perhaps a
million of which may have planets orbiting around them. Scientists want to know if these
planets exist, and if they do, are any of them like those in our solar system, or do any
harbor intelligent beings or other forms of life.
Someday, as a result of space exploration and travel, scientists may be able to solve the
mysteries of the universe. Their discoveries may also change our view of life on Earth and
of our planet's role in the universe.
Leaving the Earth
Before reaching space, scientists had to solve the problem of escaping from the Earth's
gravity--the force that pulls objects toward Earth and prevents them from floating off into
space. A spacecraft leaving Earth must travel fast enough to overcome this strong
gravitational pull. The speed needed to overcome the Earth's gravity, called escape
velocity, is about 7 miles (11 kilometers) per second, or 25,000 miles (40,000 kilometers)
per hour. Reaching escape velocity does not mean that a spacecraft has freed itself
completely from the Earth's gravitational pull, which extends far out into space. But it does
mean that the spacecraft will not fall back to Earth even if no additional power is used. As
the spacecraft continues to move away from the Earth, the gravitational force weakens until
it no longer has a significant effect on the spacecraft.
For a spacecraft to enter orbit around the Earth, it must reach a speed called orbital
velocity. The orbital velocity will depend upon how far above the Earth the craft is
supposed to orbit. For example, a spacecraft must attain an orbital velocity of about 17,500
miles (28,000 kilometers) per hour to orbit the Earth at a distance of 100 miles (160
kilometers). A slower orbital velocity is needed to keep a spacecraft in orbit farther from
Earth.
A spacecraft is sometimes put into a temporary, or parking, orbit before it is sent farther out
into space. There are two reasons for doing this. A spacecraft launched directly into space
would need more powerful, more expensive rockets. Scientists have also found that it is
easier to aim a spacecraft toward its destination if it is put into a parking orbit first.
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Navigation, Tracking, and Monitoring
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In space there are no fixed landmarks to indicate position. Yet a spacecraft is expected to
travel immense distances to its destination and perhaps land within a few hundred yards of
a specific target. Navigating a spacecraft to achieve this goal requires the help of many
engineers and technicians and the use of complex equipment and systems.
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Monitoring Systems and Crew
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Even during the quietest moments of a spaceflight, many things are happening on board
the spacecraft. Doctors working with flight controllers must know such things as the
breathing rate, pulse rate, blood pressure, and body temperature of each crew member.
Ground-based engineers need information about temperatures and pressures within the
spacecraft, the condition of its machinery and instruments, and whether any dangerous
situations may be arising. Scientists need information about the characteristics of planets
and their satellites (such as data on their gravitational and magnetic fields) and information
on atoms and molecules in space.
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Survival in Space
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On Earth, people move about comfortably under the influence of Earth's gravity, and they
take in oxygen from the air to breathe. The Earth's atmosphere protects them from deadly
radiation and falling meteorites. Earth also has abundant supplies of water, which is
necessary for survival. When people venture into space, however, they leave the only
known place where they can live naturally.
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G-Forces and the Human Body
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During the first few minutes after a spacecraft is launched, an enormous force pushes
astronauts down in their seats. You may have felt this force, although much more gently, in
a rising elevator. As the elevator accelerates, you can feel the pressure of the floor against
your feet. The force that holds you to the Earth and pulls you down is gravity.
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The normal gravitational force that holds you to the Earth has a strength of 1 g. (The g
stands for "gravity.") The pull of 1 g on your body is what is commonly called your weight.
Suppose you stood on a scale inside an elevator as it accelerated upward. You would find
that you had suddenly gained a few pounds. This is because gravity pulls you down and
causes your body to resist being moved upward. This resistance has the effect of making
you slightly heavier. The g-force on your body would be a little greater than the normal 1 g.
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Aboard the U.S. , the g-forces are never greater than 3 g. Since this is well within the
physical limitations of most people, it allows individuals who have not had special training to
go into space. It also allows the space shuttle to carry equipment that would be damaged
by high g-forces.
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Weightlessness and Its Effects
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By the time a spacecraft reaches escape velocity or orbital velocity, there are no more high
g-forces. In fact, even Earth's 1 g-force is gone. As a result, people aboard the spacecraft
experience weightlessness, or zero gravity (0 g), a state in which they feel absolutely no
gravitational pull. In a state of weightlessness, people feel lighter than a feather and float
because they weigh nothing at all.
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Several things are usually done to help crew members deal with weightlessness. Lines are
strung in the spacecraft cabin so that crew members can pull themselves along in the
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directions they want to go. The soles of shoes and the floor of the cabin are covered with a
special burrlike fabric that will stick to another similar surface. It is very similar to the Velcro
that is used today as a fastener for clothes. This fabric enables crew members to walk
around inside the spacecraft cabin during weightlessness. Astronauts are also carefully
trained to live in weightless conditions. They learn how to move, eat, drink, and handle
tools. They also learn how to sleep in a floating position, held in place in a type of sleeping
bag attached to the walls of the spacecraft.
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During periods of weightlessness, it is very important for astronauts to do certain exercises
or there may be damage to their hearts, blood vessels, bones, and muscles, which are all
adapted to the gravity of Earth. Astronauts who spend a few months in weightless
conditions do not seem harmed, but doctors are concerned about the possible effects of
weightlessness during long voyages if muscles and other bodily systems are not utilized as
they are on Earth.
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Life-Support Systems
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On Earth, every time you take a breath, fresh air is pushed into your lungs. That could not
happen in space because there is no air and no air pressure to make air move. Instead,
space is an almost perfect vacuum--an empty area with no air or atmosphere. Because of
this vacuum, astronauts need special life-support systems to survive.
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One type of life-support system is the pressurized space suit. This suit maintains proper air
pressure and temperature and also supplies oxygen for breathing. It is made out of many
layers of strong synthetic materials that can protect an astronaut from the vacuum of space
and other dangers, such as radiation. A pressurized space suit is bulky, however, and it is
uncomfortable and tiring to be inside one for very long. Therefore, scientists have created
ways to provide a "shirtsleeve environment" for astronauts when they are inside the
spacecraft. In this environment, the cabin is pressurized and its air is conditioned to protect
astronauts from the extreme cold of space, the heat of the sun, and the heat of re-entry into
the Earth's atmosphere. The cabin's air conditioning system also purifies the air, removes
moisture and carbon dioxide from the air, and adds fresh oxygen to it. Within the cabin,
crew members wear light, comfortable space suits that allow great freedom of movement
and that can be pressurized quickly in an emergency.
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When astronauts leave the shirtsleeve environment of the cabin, they must wear
pressurized space suits and carry portable life-support systems. The Apollo astronauts who
walked on the moon, for example, wore backpacks with special equipment that could keep
them alive for up to four hours..
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Food, Water, and Wastes
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The food that astronauts eat on board a spacecraft must be nutritious, easy to eat, and
convenient to store. Most ordinary foods are too bulky and heavy to take on a spaceflight,
and many spoil if they are not refrigerated. Some foods used in space are dehydrated and
freeze-dried, which is a process that removes water, leaving only a dry powdery or
pastelike substance. Freeze-dried, dehydrated foods weigh as little as one tenth of their
original weight. They take up very little space and can be kept in plastic bags at room
temperature without spoiling. Before eating the freeze-dried food, an astronaut adds some
water to the dry food while it is in the plastic bag and mixes the contents until the food is
soft. The food can then be squeezed out of the bag or sometimes eaten with a spoon.
Astronauts sometimes warm up frozen and chilled foods as well.
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Astronauts must have water for drinking, washing themselves, and preparing freeze-dried
foods. On long trips, devices called fuel cells are used to produce pure, fresh water. They
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also produce electricity for the spacecraft. When oxygen and hydrogen are piped into the
fuel cells, the two gases combine, forming water. Electricity is produced during this reaction.
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A special problem during spaceflight is how to deal with bodily wastes, such as perspiration,
urine, and solid waste. Liquid wastes, such as perspiration and urine, are processed in a
special purifying system that separates the water from the other materials in the wastes and
purifies the water so it can be used again. Solid waste materials are stored in plastic bags
that are discarded after returning to Earth.
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Dangers of Spaceflight
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Astronauts in space face a number of dangers quite unlike the dangers on Earth. One of
the most obvious dangers is the lack of atmosphere in space and the vacuum that exists
there. Without life-support systems, astronauts would be quickly killed by the space
environment. Space holds other dangers as well, including the physical and emotional
stresses of spaceflight itself.
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Dangers from Micrometeoroids
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Space is not completely empty. Floating around in it are countless tiny particles of solid
matter called micrometeoroids. Although most of these particles are much smaller than
grains of sand, they move through space at tremendous speeds--from 70,000 to 160,000
miles (112,000 to 258,000 kilometers) per hour.
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Usually micrometeoroids pose no great danger to a spacecraft. Sometimes, however, they
occur in great swarms. A spacecraft traveling through a swarm may be hit by some
particles, which could puncture the skin of the spacecraft. While tiny puncture holes may
not be dangerous, a larger hole could allow air to escape from the spacecraft cabin and
cause the air pressure to decrease quickly.
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Danger from Radiation
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In addition to micrometeoroids, space contains tiny, invisible particles of matter, known as
radiation, that are emitted by the sun and other stars. Radiation can be very dangerous to
life. Exposure to some radiation can cause physical illness and other serious health
problems. Exposure to large amounts of radiation can cause death. On Earth, the
atmosphere surrounding the planet acts as a filter to prevent most harmful radiation from
reaching us. The radiation that gets through the atmosphere is weakened enough to make
it relatively harmless. In space, however, there is no atmosphere to filter out harmful
radiation particles.
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Another radiation danger results from solar "storms" on the surface of the sun. During these
storms, great eruptions of energy called solar flares sometimes burst out from the sun,
causing unusually intense radiation to spread outward in space.
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Space Shuttles and Stations
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Many space missions in the future will depend on a permanent station orbiting high above
the Earth. In 1998, the United States, in partnership with 15 other countries--Russia,
Canada, Japan, eleven European nations, and Brazil--began assembling the International
Space Station, or ISS. It was the largest science project ever undertaken, costing $60
billion and taking an expected five years to complete. Plans called for a station powered
electrically by an array of solar panels as wide as a football field, with living and working
quarters as large as the combined cabin size of two 747 jetliners--enough for a crew of up
to seven scientists and astronauts.
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The first two pieces, or modules, of the space station were carried into orbit, one by the
U.S. shuttle Endeavour and the other by a Russian rocket. Shuttle astronauts started
assembling the modules in space in what would be a series of missions to build the station
piece by piece. They and future space construction workers will rely on various tools
developed for the shuttles, such as the Remote Manipulator System (a robotic arm that
moves objects in and out of the shuttle's cargo bay) and the MMU (manned maneuvering
unit) that allows shuttle astronauts to "fly" and work in space without using a tether
connected to a spacecraft.
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Future Space Explorations
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One of the central quests of space exploration is to discover whether life exists anywhere
else in the solar system. Life as we know it has evolved on Earth because the planet lies at
just the right distance from the sun to allow water to remain liquid and temperatures to be
moderate. Without these two conditions, life-forms as we know them could not exist.
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Search for Life on Other Planets
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Among the planets, Mars appears to be the most hospitable to life, although it is farther
from the sun and much colder than Earth. Mars has some water, frozen in polar ice caps
and perhaps in its soil, much like the permafrost in Earth's arctic lands. Mars also has a thin
atmosphere.. Although studies of the planet's surface have not revealed any signs of life,
future probes will no doubt look for remnants of life at the sites of Martian lakes that no
longer exist.
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Some scientists believe that remnants of Martian life may have already been found in
several meteorites thought to have come from Mars and crashed on Earth. In the late
1990's, NASA scientists discovered tiny wormlike features resembling fossilized bacteria in
meteorites found in Antarctica, Egypt, and India. The meteorites varied in age from 4 billion
years to 165 million years, suggesting that life once existed--and perhaps still exists--on the
red planet. Other researchers were skeptical, arguing that the microscopic features might
not be signs of life at all. The debate will no doubt continue until more convincing evidence
can be found in samples of Martian soil brought back to Earth by future space probes.
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Human Bases and Colonies in Space
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Sometime in the future, it is possible that we will establish permanent bases on the moon or
perhaps Mars. The moon is the most likely site because it is close to Earth and its weaker
gravity would allow spacecraft to use less fuel when taking off from its surface.
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Much farther in the future lies the possibility of voyages to other stars. With current methods
of rocket propulsion, however, a trip to the nearest star would take many more years than
exist in a person's lifetime. Space travel within our Milky Way galaxy, therefore, will
probably require spaceships to be "colonies," with generations of inhabitants whose entire
lives will be spent on board the space colonies as they travel on their journeys.
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Given enough time and advances in technology, it might even be possible to colonize other
parts of the galaxy. It may also be possible to build floating space colonies around nearby
stars. These colonies would be located in regions of space near enough to a star so that
there would be enough light, heat, and solar energy for human beings to survive.
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More practical than colonies far out in space would be an orbiting space colony near the
moon with room for 10,000 people. The colony could be built of lunar material, which would
be easy to transport from the moon's surface because the weak gravitational force would
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allow rockets to take off easier than they can on Earth. Solar energy would supply an
unlimited amount of power to the colony.
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The Days Ahead
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While exciting to contemplate, centuries-long space voyages, bases on the moon, and
human colonies in space will not come about for many years. However, space tourism has
become a reality. In 2001, American businessman Dennis Tito became the first civilian to
pay for a trip into space. He joined a Russian crew on an eight-day mission to the
International Space Station. Others lined up immediately for their turn in space.
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Achievements in space have been truly remarkable. Yet the future may hold even greater
triumphs. The day may come when human beings explore and inhabit the distant reaches
of space and unravel the mysteries of the universe and of life within it.
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Benefits of Space Exploration
Tega Jessa
by Tega Jessa. Originally published in Universe Today
August 24, 2009. Used with permission.
Copyright laws may prohibit photocopying this document without express permission.
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Benefits of Space Exploration
by Tega Jessa
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One of the biggest challenges to space exploration is the public and politics. A space
exploration has always been a capital intensive endeavor requiring vast resources and
extensive research. Because of this Governments have been the only organizations big
enough to foot the bill. Even more telling, only three nations so far have successfully sent
human beings into space. When something involves the spending of government dollars it
always becomes entangled in politics. This is the main point of contention surrounding
programs like health care reform and in this case, space exploration. The questions that
many American grumble out is “Why waste the money on space when we can use it down
here?”
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The answer is two-fold. We actually do spend the money down here. It goes to the salaries
of the countless worker and scientist that support every mission that NASA does. It also
goes to pay major private companies and corporations that play important roles in major
sectors of the US economy. For example one of NASA contractors for aircraft is Boeing the
same company that makes commercial aircraft for the airline industry. So as you see there
are already direct benefits to the economy provided by NASA missions. The less obvious
and most important benefit is spinoff technologies. The simple fact is that every new step
we make in space exploration advances our knowledge of not just the Universe but the
new height human innovation and technology can achieve. Some scientists have already
hypothesized that if a civilization from another part of space were to make first contact with
Earth their technology would be several orders of magnitude more advanced than ours
because the many scientific and technological milestones they would need to achieve to
make the feat even possible.
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We are surrounded every day by technologies developed for space exploration. The
artificial heart for example, resulted from experiments on the space shuttle and a
partnership with renowned heart surgeon Dr. Michael Debakey. The hand held Jaws of Life
used to save victims from car wrecks originated from the system used to separate the
space shuttle from its booster rockets. Even the insulation that keeps our homes warm and
energy efficient is based of the technology used to insulate the space shuttle.
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These advances are found in our food, our building materials, medical procedures and the
vehicles we drive. So the next time you wonder if it is a waste of time and money to explore
space remember that it is actually an investment that improves the quality of our lives.
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SpaceX Boldly Looks to Blast “Millions of People to Mars”
Miles O’Brien
O'Brien, M. (Science Correspondent). (2012, May 3). SpaceX boldly looks
to blast "millions of people to Mars” [Video file]. Retrieved from
http://www.pbs.org/newshour/bb/science/jan-june12/spacex_05-03.html
Copyright laws may prohibit photocopying this document without express permission.
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A One-Way Ticket To Mars
Lawrence M. Krauss
From The New York Times, 9-1-2009 © 2009 The New York
Times. All rights reserved. Used by permission and protected by
the Copyright Laws of the United States. The printing, copying,
redistribution, or retransmission of this content without express
written permission is prohibited.
Copyright laws may prohibit photocopying this document without express permission -31-
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A One-Way Ticket to Mars
Lawrence M. Krauss
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NOW that the hype surrounding the 40th anniversary of the Moon landings has come and
gone, we are faced with the grim reality that if we want to send humans back to the Moon
the investment is likely to run in excess of $150 billion. The cost to get to Mars could easily
be two to four times that, if it is possible at all.
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This is the issue being wrestled with by a NASA panel, convened this year and led by
Norman Augustine, a former chief executive of Lockheed Martin, that will in the coming
weeks present President Obama with options for the near-term future of human spaceflight.
It is quickly becoming clear that going to the Moon or Mars in the next decade or two will be
impossible without a much bigger budget than has so far been allocated. Is it worth it?
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The most challenging impediment to human travel to Mars does not seem to involve the
complicated launching, propulsion, guidance or landing technologies but something far
more mundane: the radiation emanating from the Sun’s cosmic rays. The shielding
necessary to ensure the astronauts do not get a lethal dose of solar radiation on a round
trip to Mars may very well make the spacecraft so heavy that the amount of fuel needed
becomes prohibitive.
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There is, however, a way to surmount this problem while reducing the cost and technical
requirements, but it demands that we ask this vexing question: Why are we so interested in
bringing the Mars astronauts home again?
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While the idea of sending astronauts aloft never to return is jarring upon first hearing, the
rationale for one-way trips into space has both historical and practical roots. Colonists and
pilgrims seldom set off for the New World with the expectation of a return trip, usually
because the places they were leaving were pretty intolerable anyway. Give us a century or
two and we may turn the whole planet into a place from which many people might be happy
to depart.
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Moreover, one of the reasons that is sometimes given for sending humans into space is
that we need to move beyond Earth if we are to improve our species’ chances of survival
should something terrible happen back home. This requires people to leave, and stay
away.
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There are more immediate and pragmatic reasons to consider one-way human space
exploration mission. First, money. Much of the cost of a voyage to Mars will be spent on
coming home again. If the fuel for the return is carried on the ship, this greatly increases the
mass of the ship, which in turn requires even more fuel.
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The president of the Mars Society, Robert Zubrin, has offered one possible solution: two
ships, sent separately. The first would be sent unmanned and, once there, combine
onboard hydrogen with carbon dioxide from the Martian atmosphere to generate the fuel for
the return trip; the second would take the astronauts there, and then be left behind. But
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once arrival is decoupled from return, one should ask whether the return trip is really
necessary.
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Surely if the point of sending astronauts is to be able to carry out scientific experiments that
robots cannot do (something I am highly skeptical of and one of the reasons I don’t believe
we should use science to attempt to justify human space exploration), then the longer they
spend on the planet the more experiments they can do.
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Moreover, if the radiation problems cannot be adequately resolved then the longevity of
astronauts signing up for a Mars round trip would be severely compromised in any case. As
cruel as it may sound, the astronauts would probably best use their remaining time living
and working on Mars rather than dying at home.
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If it sounds unrealistic to suggest that astronauts would be willing to leave home never to
return alive, then consider the results of several informal surveys I and several colleagues
have conducted recently. One of my peers in Arizona recently accompanied a group of
scientists and engineers from the Jet Propulsion Laboratory on a geological field trip.
During the day, he asked how many would be willing to go on a one- way mission into
space. Every member of the group raised his hand. The lure of space travel remains
intoxicating for a generation brought up on “Star Trek” and “Star Wars.”
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We might want to restrict the voyage to older astronauts, whose longevity is limited in any
case. Here again, I have found a significant fraction of scientists older than 65 who would
be willing to live out their remaining years on the red planet or elsewhere. With older
scientists, there would be additional health complications, to be sure, but the necessary
medical personnel and equipment would still probably be cheaper than designing a return
mission.
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Delivering food and supplies to these new pioneers — along with the tools to grow and
build whatever they need, for however long they live on the red planet — is likewise more
reasonable and may be less expensive than designing a ticket home. Certainly, as in the
Zubrin proposal, unmanned spacecraft could provide the crucial supply lines.
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The largest stumbling block to a consideration of one-way missions is probably political.
NASA and Congress are unlikely to do something that could be perceived as signing the
death warrants of astronauts.
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Nevertheless, human space travel is so expensive and so dangerous that we are going to
need novel, even extreme solutions if we really want to expand the range of human
civilization beyond our own planet. To boldly go where no one has gone before does not
require coming home again.
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