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Mission
Specialist Richard A. Mastracchio
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The Space Shuttle is used as a laboratory in space in which
scientists on the ground do a variety of activities.
Astronauts take photographs and videotapes of the
Earth to allow scientists to study the complex interactions
of atmosphere, oceans, land, energy, and living things.
They take scientific instruments into space above
the filtering effects of the atmosphere, making the
entire electromagnetic spectrum available which allows
us to more clearly see the distant planets, stars,
and galaxies. |
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Spacelab.
Click to enlarge image. |
Spacelab
is a module designed and built by the European Space
Agency. It fits snugly inside the Shuttle's
cargo bay and is enclosed and pressurized to provide
a comfortable work environment for astronauts conducting
the experiments. Spacelab has experiment equipment
racks installed in the ceiling and floor as well as
in the walls since there is no up or down in space.
Spacelab is a series of modular components that can
be assembled into unique mission configurations.
Spacelab has proven invaluable to microgravity scientists
since it provides them with a shirt-sleeve laboratory
environment with the resources necessary to conduct
experiments.
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Microgravity research
experiments that have been done on the Shuttle and
on the Spacelab have been in the fields of biotechnology,
biomedicine, fluid physics, combustion science,
materials science, and space science. Many
experiments have been done on the Space Shuttle
that have used satellites to house or accomplish
other experiments. Some of these include the
Hubble Space Telescope, the
Space Tether experiments, and many other science
satellites such as the
Solar Maximum satellite.
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Astronaut Gerhard P. J. Thiele,
mission specialist, checks an Earth target
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The Office of Earth Sciences
at the Johnson Space Center trains astronauts in
Earth observations, communicating with on-orbit
astronauts about weather and other Earth processes
during missions, and cataloging and archiving the
photographs they take using handheld cameras.
The Gateway
to Astronaut Photography of Earth database
records the location and a description of over 680,000
astronaut photographs of Earth from the beginning
of NASA spaceflight.
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| Some
of the features studied and documented include volcanic
eruptions, transatlantic duststorms, deforestation
in the rain forests of Brazil, dramatic changes in
the extent of the world's great river deltas, plankton
blooms tens of miles long, human modification of the
coastal zone, coral reefs, and the effects of El Niños_from
droughts in Australia to floods in California, long-term
changes such as the rise and fall of lake levels,
gradual changes in land-use patterns, and dynamic
patterns in the ocean surface waters. Click
here for a clickable Earth map of photos taken
from the Space Shuttle.
Due to our
usually limited view from the Earth's surface, it
has often been difficult to observe or record these
events on a large scale. Spaceflight provides a unique
platform for continual observations of the Earth's
changing surface, providing scientists with a better
understanding of our planet. Visual Earth observations
from space use trained astronauts to quickly identify
and photograph interesting phenomena and sites.
Visit the NASA
Visible Earth site to search for images and visualizations
of the Earth! |
Supertyphoon Winnie August
15, 1997 (the Shuttle robot arm is seen in the image).
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The Shuttle
Radar Topography Mission, (SRTM) in February
of 2000, mapped 80% of the Earth and acquired topographic
data of more than 47.6 million square miles of the
Earth's surface in stereo relief. All of the radar
data was collected during a single, 11-day Space
Shuttle mission, STS-99. Click
here to read about the Topographic Mapping
mission.
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STS-57
Pilot Brian J. Duffy talks with amateur radio operators
on the Earth
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The
SAREX, or Shuttle Amateur Radio Experiment, allows
amateur radio operators to work with local schools
to talk to crews on board the Space Shuttle. Students
present a series of questions to the crew during a
mission via a radio transmission directly from the
Shuttle to the amateur radio station.
SAREX has
flown on many SpaceHab missions and is a great way
to encourage students to think about science, spaceflight,
and communications. More than 200 schools have participated
in the program so far! |
Astronaut Jeff Hoffman of
the STS-51D Toys in Space Mission
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The
Toys in Space missions were done on STS-51D and STS-54.
They provided school children with a series of experiments
that they could do in their classrooms using a variety
of toys that demonstrates the laws of physics.
The astronauts on those flights experimented with
the toys and videotaped their results. Students
could then compare their results to what actually
happened in space.
Some of
the toys that were flown included gyroscopes, balls
and jacks, yo-yos, paddle balls, Wheelos®, and
Hot Wheels® cars and tracks.
Click
here to watch the video of the Toys in Space
II flight.
Check out
all the Toys
in Space II toy and experiment descriptions.
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Toys used on the Toys in Spaceflight
STS-51D |
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Satellite Deploy and
Retrieval
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A large variety of satellites
have been deployed, repaired, and retrieved on the
Space Shuttle. Many of them included experiments
that were done in microgravity. The Long
Duration Experiment Facility was deployed
for 5.7 years and included 57 experiments and materials.
When
returned to Earth, scientists could study the effect
of space debris, thermal fluctuations, and cosmic
and solar radiation on the different materials that
were exposed to space. LDEF was designed to provide
long-term data on the space environment and its
effects on space systems and operations.
The TDRSS
or tracking and data and relay satellite system
has been deployed by the Shuttle over several years
to transfer communications from ground stations
around the world to satellite systems in space. This
system provides the Shuttle with better communications
coverage during its missions.
ATLAS
satellites were used to study the effects of
the solar wind and the composition of the solar
corona.
The
Wake Shield Facility satellites were 12-foot
diameter, free-flying, stainless-steel disks designed
to generate an "ultra-vacuum" environment
in space in which to grow semiconductor thin films
for use in advanced electronics.
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Tethered
Satellite Experiment
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| The tethered satellite experiments in 1992 and 1995
allowed the astronauts to try to send a tethered satellite
out from the Shuttle on a long tether to study the practicality
of tethered structures in space. Although the first
mission was unsuccessful and the tether failed to deploy,
the second experiment was successful. It gave scientists
and engineers data on how to improve such systems for
future application. Click here to watch the tethered
satellite video Part
One and Part
Two. Manipulating a satellite on a tether from
the Orbiter is a unique engineering challenge. Because
gravity, centrifugal acceleration, and atmospheric drag
vary with altitude, each of the two bodies in a tethered
system is subject to different influences. |
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Galileo
being deployed by the Shuttle Atlantis in 1989.
It arrived at Jupiter in December of 1995.
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Planetary
Spacecraft
The Magellan
spacecraft was launched from the Shuttle and traveled
to Venus, orbiting and mapping the planet. The
Galileo
spacecraft was launched from the Shuttle and traveled
to Jupiter to photograph and study Jupiter and its
moons. The Ulysses spacecraft was launched from
the Shuttle to study the Sun and the solar wind.
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Jupiter's
Giant Red Spot in infrared. Click on the image to
see the movie showing the motion.
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Space
Telescope
Three
large space telescopes have been deployed from the
Space Shuttle including the
Hubble Space Telescope in 1990.
Hubble,
which has been visited by crews to replace and upgrade
equipment over the past 10 years, has returned some
of the most amazing views of deep space, giving
astronomers vast quantities of data about the origin,
development, and structure of the universe.
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Snails in the closed equilibrated
biological aquatic system (CEBAS)
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Scientists use space as
a unique research laboratory that answers fundamental
questions in basic biology and physiology. Space biology
researchers investigate how cells, plants, and animals
sense and respond to gravity and radiation. These studies
have increased our basic understanding of gravity's
effects on cell structure and metabolism. |
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Space biology research has also helped scientists
learn more about how living organisms sense gravity.
NASA researchers have seen changes in the gravity-sensing
organs in the inner ears of rats when they are flown
in space. Using computers, scientists developed
models of these organs that helped uncover the fundamental
organization of gravity sensors. This research
overturned a 50-year-old concept of gravity sensor
organization. The results have implications for
understanding, preventing, and treating diseases
that affect gravity sensors. Because the basic
organization of the gravity sensors is similar to
that of the retina in the eye and other parts of
the nervous system and brain, this research has
great potential for helping us to understand the
basis for learning and memory.
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Space
biology researchers investigate how cells, plants,
and animals sense and respond to gravity and radiation.
Plant development has emerged as a particularly
challenging aspect of space biology, largely due
to a number of intriguing observations that suggest
that spaceflight affects how plants develop and
reproduce.
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Environmentally
controlled plant growth chambers.
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Researcher
Dr. Yi Li first flew plant experiments on board
STS-63. Dr. Li discovered that exposure to microgravity
increased a particular hormone concentration in
plants. Since that time, Dr. Li has been able to
manipulate this phenomenon and grow fruits, such
as tomatoes, that overproduce the hormone. These
plants thus bear larger seedless fruit in the absence
of pollination.
Gravitropism
is the bending response of plants to the force
of gravity with the roots growing downward and
the shoots growing upward. Charles Darwin began
experiments on plant gravitropism during the last
century.
NASA's
research with plants in space is dedicated to
systematic studies that explore the role gravity
plays at all stages in the life of higher plants.
It includes scientific questions focused on determining
the effects of interactions of gravity and other
environmental factors on plant systems, and on using
microgravity as a tool to advance our fundamental
knowledge of plant biology. Plant research results
contribute to NASA's goals of furthering the human
exploration of space and improving the quality of
life on Earth through applications in medicine,
agriculture, biotechnology, and environmental management
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Biospecimen
Sharing
Biospecimen
sharing provides the scientific community with
access to NASA's inventory of biological materials
from organisms that have flown in space. These materials
were not required by the primary experiments of the
spaceflights on which they were flown. Available material
often includes material flight and/or ground control
studies that were designed to enable the primary investigation
to be carried out successfully. Only limited tissues
are available due to the rigorous review and justification
process employed by NASA to qualify research activities
for spaceflight experiments and/or animal experiments.
Rodent, avian, and plant materials are available
from previously flown flight experiments.
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STS-9 Mission Specialists Robert A. R. Parker,
at left, and Payload Specialist Ulf Merbold
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The effects
of spaceflight on the human body are similar to
symptoms of many diseases on Earth. Researchers
study astronauts to improve our understanding
of the human body, contributing to the medical
knowledge and improving health care technology.
NASA
works with other government agencies such as the
National Institutes of Health to sponsor a
wide variety of experiments to understand the
effects of spaceflight on the brain, heart, lungs,
and kidneys.
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Heart
rate, blood pressure, and lung function all change
during spaceflight. Over time, complex interactions
between the kidneys and the endocrine system alter
the balance of fluids in astronauts' bodies. Knowledge
from space research will be applied to understanding
and treating diseases that affect millions of
Americans.
During
spaceflight, astronauts also experience changes
in the systems that provide their sense of balance,
leading to disorientation, dizziness, and motion
sickness.
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Astronaut undergoing preparation
for sleeping in space study
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By studying
the neurovestibular system in astronauts, scientists
seek fundamental knowledge about the causes of balance
disorders on Earth. Check out the National
Space Biomedical Institute. Read more
in the online article Space
Science in the Twenty-First Century, Imperatives
for the Decades 1995 to 2015: Life Sciences, Human
Biology and Space Medicine.
Microgravity Research
Working
in partnership with the scientific community
and commercial industry, NASA's Microgravity
Research Program and the Microgravity Science
Division strive to increase our understanding
of the effects of gravity on biological, chemical
and physical systems. Using both spaceflight
and ground-based experiments, researchers
throughout the nation, as well as international
partners, are working together to benefit
economic, social, and industrial aspects of
life for the United States and the entire
Earth.
Microgravity
research has been performed by NASA for more
than 30 years. The term microgravity literally
means a state of very little gravity. The
prefix 'micro' comes from the Greek word 'mikros',
meaning small. In metric terms, the prefix
means "one part in a million". Gravity
dominates everything on Earth, from the way
life has developed to the way materials interact.
But aboard a spacecraft orbiting the Earth,
the effects of gravity are barely felt. In
this microgravity environment, scientists
can conduct experiments that are all but impossible
to perform on Earth.
Microgravity
research is divided into five science
disciplines. The science disciplines include
biotechnology,
fluid physics,
materials science,
combustion science, and
fundamental physics. Other activities
include the
Glovebox Flight Program. |
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Biotechnology
is an applied biological science that involves
the research, manipulation, and manufacturing
of biological molecules, tissues, and living
organisms. NASA's Microgravity Biotechnology
Program focuses on protein crystal growth
and mammalian cell and tissue culture.
Scientists are studying proteins because they
perform many functions in the human body. These
functions include transporting oxygen and chemicals
in the blood, forming major components of muscle
and skin, and fighting disease. Viruses, which
are also protein structures, are of interest
to researchers as well. They seek to understand
the structure of proteins and viruses by growing
protein and virus crystals suitable for structural
analysis by X-ray diffraction. Research indicates
that many crystals of these materials grown
in low gravity yield substantially better structural
information than crystals grown on Earth, since
the effects of gravity adversely influence crystal
development. |
Protein crystal grown
in space |
| Protein
crystal research could also ultimately
aid in the development of more effective drugs
and life-saving treatments for many diseases.
Since the mid-1980s, NASA has sponsored protein crystal growth experiments to
learn about the effects of space on the growth
process and to refine techniques for obtaining
the highest-quality crystals in space and
on the ground. The result is that, generally,
protein crystals produced in space are larger
and more precisely ordered than those produced
on Earth. These improvements are important
to scientists who analyze a crystal's three-dimensional
structure_the key to understanding
a protein's activity_and
possibly developing new and more effective
medicines.
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| These studies also are developing new tissues
for potential transplant operations.
Biotechnology research results have provided
significant advances in the understanding of
many diseases including AIDS, heart disease,
cancer, diabetes, and hepatitis. Grown under
the influence of Earth's gravity, tissue cultures
fail to take on their full three-dimensional
structure. NASA has developed the bioreactor,
a rotating culture vessel that simulates low-gravity.
Lung tissue, human intestinal cultures, breast
and colon cancer, and cartilage have all grown
successfully in NASA's Bioreactor. |
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| On Earth, most tissue cultures grow in flat
trays; but growing such tissues in reduced-gravity
facilities has produced three-dimensional structures
that are larger and more representative of tissues
found in the human body. This has been accomplished
by using bioreactors,
which are horizontal cylinders that rotate to
inhibit the full effects of gravity, both on
Earth and aboard the Space Shuttle. By using
these methods of study, scientists have been
able to cultivate and study both cancerous and
healthy cells and tissue. As scientists become
more successful in cell and tissue culturing,
they will have to rely less often on human subjects
for their studies. |
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A
fluid is any material that flows in response
to an applied force; thus, liquids and gases
are both fluids. Fluid physicists seek to
better understand the physical principles
governing fluids, including how fluids interact
with solid boundaries; how fluids flow under
the influence of energy, such as heat or electricity;
how particles and gas bubbles suspended in
a fluid interact with and change the properties
of that fluid; and how fluids change phase,
either from fluid to solid or from one fluid
phase to another.
Fluid phenomena studied in space range
in scale from microscopic to the size of the
atmosphere, and include everything from the
transport of cells in the human body to changes
in the composition of the atmosphere. |
Astronaut Kenneth D.
Bowersox studies the movement of fluids in
microgravity |
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Astronaut Bonnie Dunbar
with fluid physics experiment
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Microgravity fluid physicists
use microgravity environments to increase our
knowledge of fluid behavior to advance science
and technology. Understanding the fluid-like
behavior of soils under stress will help civil
engineers to design safe buildings in earthquake-prone
areas. Materials engineers can benefit from
a better grasp of how the structure and properties
of a solid metal are determined by fluid behavior
during its formation. And, knowledge of the
flow characteristics of vapor-liquid mixtures
is useful in designing power plants to ensure
maximum stability and performance. |
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Many of our intuitive
expectations do not hold up in microgravity,
because other forces such as surface tension
control fluid behavior. Surface tension causes
drops of any liquid to form almost perfect
spheres when the influence of gravity is absent.
On Earth, gravity distorts the shape of liquid
when it is resting on or attached to a surface.
While these differences in fluid behavior often present engineers
and astronauts with practical problems, they
also offer scientists unique opportunities
to explore different aspects of the physics
of fluids.
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Materials Science
Materials
scientists seek to understand the formation,
structure, and properties of materials on
various scales, ranging from atomic to microscopic
to macroscopic levels. Fundamental to the
study of materials is establishing quantitative
and predictive relationships between the way
a material is produced (processing), its structure
(how the atoms are arranged), and its properties.
Materials science research in microgravity
may lead to better understanding of the processes
used to produce these materials on Earth.
Microgravity experimentation may eventually
allow the production of limited sample quantities
of high-quality materials or of samples exhibiting
unique properties for use as theoretical benchmarks. |
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In addition,
researchers may also find ways to combine
materials to obtain unique structures in microgravity
that ordinarily would not form under the effects
of Earth's gravity. This may lead to the creation
of new types of materials that perform better
than current materials or that have properties
unlike any available today.
The microgravity Materials Science
Program uses the unique characteristics of
the microgravity environment to study fundamental
issues in materials solidification and crystal
growth. Of particular interest is the study
of the roles played by the formation of electronic
and photonic materials, metals, alloys, composites,
glasses, ceramics, and polymers.
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Astronaut John Blaha
working on a mechanics of granular materials
experiment |
In
the production of electronic materials, crystals
have achieved far greater value as conductors
than they ever had as gemstones. Pioneering
research is leading to next-generation commercial
crystal products. Material science also has
a focus on the production of alloys and composites.
High-strength metals are needed in the aviation,
aerospace, power-generation, and propulsion
industries. |
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Processing these materials in space helps
researchers to understand how to make better
materials on Earth and is allowing scientists
to create new metal alloys. Alloys are mixtures
of metals or metals and nonmetals. When combined,
alloys can produce materials with improved strength
or better resistance to corrosion. Material
research results will contribute to future
models of industrial and manufacturing processes.
This will lead to new, stronger, lighter alloys
with never-before-seen properties. Marshall
Spaceflight Center in Huntsville, Alabama, is
responsible for implementing work in the microgravity
discipline of materials science. |
The
Microgravity Combustion Science Program
supports research in how flames ignite, spread,
and extinguish under microgravity conditions.
Combustion, or burning, is a rapid, self-sustaining
chemical reaction that releases a significant
amount of heat. The Glenn Research
Center in Cleveland, Ohio, is the Microgravity
Center of Excellence for combustion science.
The
objectives of NASA's Microgravity Combustion
Science Program are to improve understanding
of fundamental combustion phenomena affected
by gravity, to use research results to advance
combustion science and technology on Earth,
and to address issues of fire safety in space.
Check out information about the combustion
modules that flew on the Space Shuttle!
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Astronaut Janice Voss
is opening the lid of the combustion chamber
of the combustion module-1 |
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Combustion
research in space provides scientists
with never-before-seen insights into the most
important chemical process in our everyday
lives. Results of this research may lead to
cleaner and more efficient fuels, automobile
engines, and heating systems and to better
fire safety on Earth and in spacecraft.
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Flame in normal gravity. |
Since the physical and chemical mechanisms
that cause flames to spread on Earth are strongly
influenced by gravity, researchers are finding
out flames behave very differently in the
low gravity of an orbiting spacecraft. It
is well known that material flammability and
flame growth are strongly affected by the
environment, including oxygen content, pressure
and air flow. However, the effects of these
conditions in the microgravity environment
are largely unknown. Scientists want to understand
combustion to improve efficiency of our fuel-driven
machines and to evaluate potential fire hazards
aboard spacecraft. |
Flame in microgravity. |
| Fundamental
physics is the study of the basic laws that
govern the properties of the physical world
on all scales, from microscopic to cosmic.
The study of fundamental physics in the microgravity
environment can yield entirely new or
substantially improved results when the obscuring
effects of Earth's gravity are not present.
Researchers
will use the microgravity environment to test
some of the most
fundamental theories of physics. This
research is important because it seeks to
uncover the principles that govern the behavior
of the physical world, such as the influence
of heat energy, new forms of matter, and low-temperature
physics. The Jet Propulsion Laboratory
in Pasadena, California, is responsible for
implementing work in the microgravity discipline
of fundamental physics. |
Astronaut Jay Apt at
work
on the Shuttle middeck |
| Theories resulting from studies
of superfluid helium in microgravity can help
us to understand many other systems. Scientists
can use these theories to better understand
the formation of weather systems, such as tornadoes
and hurricanes; how water seeps through soil;
and how cracks propagate in metals.
Another
area of research in microgravity fundamental
physics is
laser cooling and atomic physics. Researchers
working in this area are interested in the
study of the structure of isolated atoms and
their interactions with external stimuli,
such as other atoms, surfaces, electromagnetic
fields, temperature, pressure, and light.
Laser cooling technology provides a new method
of investigation in which atoms are bombarded
with light to slow their movement, allowing
scientists a longer time to observe them.
Microgravity will improve this technology
by eliminating the external stimulus of gravity,
which affects the motions of atoms.
Fundamental
physics research will also play a significant
role in the human exploration and development
of space. Engineers have already designed
atomic clocks, which use laser-cooled atoms
to maintain high-precision time standards.
These clocks can be used to help spacecraft
maintain accurate courses over vast distances
and to help aircraft make more precise landings
in situations that require automatic landing
systems, such as in inclement weather or when
visibility is limited. |
Cosmonaut Yury V. Usachev
working at the glovebox |
The
Glovebox Flight Program is a microgravity
infrastructure program that provides facilities
for performing investigations that do not
require large, specialized equipment. The
glovebox offers scientists the capability
to conduct microgravity research experiments,
test science procedures, and develop new technologies
in microgravity.
A glovebox is an enclosed volume that
provides physical isolation of an experiment
from its environment and enables astronaut
manipulation of experiment hardware through
gloveports.
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| In general, glovebox
experiments are smaller in scale, less complex,
less automated, more crew-intensive, and use
fewer diagnostics than the typical larger-scale
spaceflight experiments. Gllovebox investigation
hardware can be developed within two to three
years at a fraction of the cost of most larger-scale
experiments.
Questions
to think about:
- Which area of microgravity research or
space biology interests you? Why?
- If you were to design an experiment for
the microgravity environment, what would
it be?
- What do you think is the best reason for
doing research in a microgravity environment?
In the next lesson,
you will learn about what makes up a space
suit and what types of tools and equipment
astronauts use on a spacewalk.
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