Glossary
Astronaut = pilot or passenger (crew) of a spacecraft
Astronauts are currently living and working on board the ISS.
Experiment = practical test to study and try to understand a phenomenon.
To study the effect of light on plants, scientists carry out experiments.
Gravity = the natural attraction that exists between two bodies of mass. The greater the mass, the greater the gravity.
Laboratory = a place designed and equipped to carry out scientific experiments.
The ISS is a laboratory in which astronauts do experiments under conditions of weightlessness.
Orbit = the path of an object moving around another body in space.
The Moon and satellites are in orbit around the Earth.
Planet = a large solid body which orbits around a star.
In the solar system, the Earth and eight other planets orbit around the Sun.
Radio communication = communication between two people using instruments able to transmit and receive radio waves through space. These radio waves can carry the sound of a voice from one point to another. Radio waves are like waves in the sea, which convey water from the sea to the coast.
Rocket = vehicle that carries astronauts and/or satellites from Earth into space.
The European rocket, Ariane-5, is launched from Kourou in French Guiana.
Satellite = an object orbiting around a larger object.
Many artificial satellites have been sent by human beings to orbit around the Earth. They include Earth observation and telecommunication satellites.
Space = area in which the stars, planets and galaxies and other celestial bodies move. It is infinite and contains all the objects in the Universe.
Spacesuit = a suit worn by astronauts when they leave their spacecraft to do a spacewalk. It enables them to carry oxygen and provides protection from extreme temperatures and the Sun's rays.
Weight = a measure of the force which the Earth's pull exerts on a body. Because an elephant has a larger mass than a human, it is subject to greater attraction and therefore weighs more.
Weightlessness = the absence of gravity.
Astronauts in space live in a state of weightlessness.
If you would like us to add other words to this glossary, email us at ISSeducationteam@esa.int
