Gravity is a force that governs motion throughout the universe.
It holds us to the ground and keeps the Earth in orbit around the Sun. In free fall, an object falls faster and faster, accelerating with exactly the speed of attraction caused by gravity. Objects travelling around the Earth in a state of continuous free fall, or orbit, are essentially weightless even though their mass remains the same. Conducting research in a microgravity environment gives researchers a unique opportunity to study the true nature of processes and materials without having to consider the effects of Earth's gravity. Thus, physics theories can be tested at levels of accuracy that are impossible on Earth.