Parabolic Flight

Abstract

Sustained weightlessness is only achievable during spaceflight. However, very short duration weightlessness can be created within the Earth’s atmosphere by allowing an airplane to follow a parabolic flight trajectory which includes a free fall period symmetrical around the top of the parabola. Because all resultant forces acting on the airplane, such as thrust, drag, lift, and gravity on the airplane, cancel each other out, true weightlessness is achieved for the duration of the free-fall maneuvers. The weightlessness phase is preceded and followed by periods of hypergravity induced by acceleration (pull-up phase) and deceleration (pull-out of the fall phase). While the bouts of weightlessness are short-lived, usually 25–35 s, they are reproducible and can be performed many times in a series. Parabolic flight is therefore a cost-effective tool in research aimed at both physics, materials science, and human physiology, as well as for astronaut training. Some limitations apply due to the hypergravity phases and the short duration. Several parabolic flight platforms are currently operational in many countries across the world, managed by various national space agencies or interest groups and utilizing airplanes ranging from large passenger jets to small two-person airplanes.