Space science performed from vehicles that travel into Earth’s upper atmosphere or beyond covers a broad range of disciplines, from meteorology and geology, to lunar, solar, and planetary science, to astronomy and astrophysics, to the life sciences. The study of space and of outer space is, of course, not the common man’s cup of tea, but the interests of mankind are deeply involved when space is put to certain uses, not all of which are peaceful.
In a matter of hours a person can fly from one continent to another; the communications gap has been bridged by what seem to be fantastic means through space. The air in space has also been used for radio broadcasts and television programmes for instruction and entertainment. Radio waves with different wavelengths have been put to various uses. The spectacular advances in space technology have enabled mankind to scan outer space. Today we can study astral phenomena from ground based radio, optical and infrared telescopes and also ultraviolet X-ray and Gamma ray telescopes functioning above the atmosphere of the earth.
Studying space science at its largest scale therefore provides some of the deepest insights into physics on the smallest scale. ESA Science is now providing access to the largest science laboratory we have ever known our Universe. Zero Gravity can simply be defined as the state or condition of weightlessness. It also refers to the state in which the net or an apparent effect of gravity is zero.
Astronauts orbiting the Earth in a space station experience zero gravity or weightlessness because their spacecraft continuously undergoes changes in velocity in its orbit in order to prevent it from being pulled into the atmosphere. The feeling is completely different from being on a roller coaster. It is more like motionlessness than movement.