astronaut: Someone trained to travel into space for research and exploration.
atmosphere: The envelope of gases surrounding Earth, another planet or a moon.
average: (in science) A term for the arithmetic mean, which is the sum of a group of numbers that is then divided by the size of the group.
engineering: The field of research that uses math and science to solve practical problems.
environment: The sum of all of the things that exist around some organism or the process and the condition those things create. Environment may refer to the weather and ecosystem in which some animal lives, or, perhaps, the temperature and humidity (or even the placement of things in the vicinity of an item of interest).
International Space Station: An artificial satellite that orbits Earth. Run by the United States and Russia, this station provides a research laboratory from which scientists can conduct experiments in biology, physics and astronomy — and make observations of Earth.
microgravity: Gravity that is a fraction of the force experienced at sea level on Earth.
moon: The natural satellite of any planet.
orbit: The curved path of a celestial object or spacecraft around a galaxy, star, planet or moon. One complete circuit around a celestial body.
physical: (adj.) A term for things that exist in the real world, as opposed to in memories or the imagination. It can also refer to properties of materials that are due to their size and non-chemical interactions (such as when one block slams with force into another). (in biology and medicine) The term can refer to the body, as in a physical exam or physical activity.
satellite: A moon orbiting a planet or a vehicle or other manufactured object that orbits some celestial body in space.
space shuttles: The world’s first reusable vehicles, NASA’s five space shuttles (Columbia, Challenger, Discovery, Endeavor and Atlantic) ferried astronauts and cargo into orbit, including to service satellites (like the Hubble Space Telescope) and the International Space Station. The first shuttle launched on April 12, 1981. On July 21, 2011, a shuttle returned home for the last time. After that trip, the program was retired. In all NASA’s shuttles tackled 135 missions.
technology: The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.
