| Antimatter |
Matter that is made up of antiparticles
(antiprotons, antineutrons, and positrons). When matter and antimatter
collide, they are both completely transformed into energy. |
| Battery |
An energy storage that
relies on chemical reactions to release stored energy. |
| Centrifuge |
A large machine used
to spin something in circles at high speeds. The spinning causes objects
inside the centrifuge to experience high forces, pushing them against
the wall. |
| Chemical reaction |
A rearrangement of atoms in compounds. |
| Combustion |
A chemical reaction usually involving
the reaction of oxygen with another substance. |
| Compound |
A grouping of atoms
that are in some way bound to each other. |
| Docking |
When a spacecraft physically connects
with something else (usually a space station or another spacecraft). |
| Force |
The product of an object's
mass and the rate at which it is accelerating. A force is what causes
objects to speed up or slow down. Examples are the pull of gravity
or a person pushing a vacuum cleaner. |
| Fuel cell |
An energy source that converts the energy released by the combination of oxygen and hydrogen to water directly into electricity. |
| Fusion |
A nuclear reaction in which two lighter atoms are fused together to form a heavier atom and a large amount of energy. |
| Gastroenterological |
Having to do with the
stomach, intestines, or other digestive organs. |
| Hearing loss |
A common result of long
space missions due to the loud noises caused by computers, machines,
and various other things aboard spacecraft. |
| Impulse |
A measure of how much
the momentum of an object has changed. |
| Insulation |
A substance that does
not allow heat to pass through it easily. It can be used to either
keep heat out (such as blocking the sun's extreme heat), or keep heat
in. |
| Ion |
An atom that has more or fewer electrons than protons, giving it a negative or positive charge. |
| Isotope |
Atoms of the same element
with different numbers of neutrons. |
| Mach |
A unit used to measure
speed relative to the speed of sound. Mach 1 is the speed of sound,
Mach 2 is twice the speed of sound, etc. |
| Microgravity |
An environment with little, if any,
gravity, such as in space. |
| Mole |
A unit of measure such that a mole
of something is equal to 6.022*10^23 of that thing. This number is
important because a mole of protons or neutrons is about 1 gram. So
if an element has an atomic mass of 12 (the mass number given on a
periodic table), a mole of that element would have a mass of 12 grams.
Because atoms are so small, it is usually easier to work with moles
of atoms. |
| Molecule |
A type of compound in
which the atoms of the compound are bound together by a sharing of
electrons. |
| Momentum |
The product of an object's mass
and velocity. It is the property of an object that determines how
easy it is to stop the object from moving. |
| Newton's laws |
Three laws of nature
that are used extensively in mechanics, the branch of physics that
focuses on how things move. |
| Osteoporosis |
The weakening of bones due to loss
of calcium. In microgravity, bones have less stress on them and do
not require as much strength for support. |
| Plasma |
A state of matter consisting of
electrons and atoms stripped of their electrons. It is the most common
state of matter in the universe. |
| Propellant |
A substance that shoots out one
end of a propulsion system that causes the spacecraft to move in the
opposite direction. |
| Psychological effects |
Changes in how people think and
act due to high stress and close confinement during long space flights |
| "Puffy-Head Bird-Legs"
syndrome |
A syndrome named for
its appearance that occurs when sinuses swell and blood shifts away
from the legs. This occurs in space as a result of microgravity. |
| Radiation |
Energy that can travel
through space (as opposed to a form of energy such as heat, which
requires the presence of matter to travel). Radiation can be harmless,
like light or radio waves, or harmful, like gamma rays. |
| Radiators |
A system that gives off or radiates heat. |
| Radioisotope |
An isotope of an element that is
unstable and emits radiation. |
Radioisotope
Thermoelectric
Generator
(RTG) |
An electricity generator that gets energy from the heat caused by the decay of radioisotopes. |
| Rendezvous |
A planned meeting between
a spacecraft and another object. This can include a spacecraft rendezvousing
with a space station, or a space probe rendezvousing with a planet
or comet. |
| Solar panel |
A panel that is able
to convert light energy into electricity. |
| Space adaptation syndrome |
The feeling of motion sickness often
experienced by astronauts due to microgravity. |
| Space debris |
Free-floating particles in space
that range in size from tiny dust particles to large pieces of rock. |
| Specific impulse |
The total impulse a propulsion system
can provide divided by the total weight of the fuel used to achieve
the impulse. |
| Suppression |
The holding back of something to
prevent it from spreading. |
| Thermocouples |
Objects that can convert thermal
energy directly into electricity. |
| Thrust |
How hard the propellant of a propulsion
system pushes on a spacecraft. |
| "Vomit Comet" |
A special airplane used
by NASA to train astronauts, which freefalls for 20 seconds, providing
trainees with the feeling of a weightless environment. |
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