A reduced-gravity aircraft is a type of fixed-wing aircraft that provides brief near-weightless environments for training astronauts, conducting research, and making gravity-free movie shots.
Versions of such airplanes were operated by the NASA Reduced Gravity Research Program,[1] and one is currently operated by the Human Spaceflight and Robotic Exploration Programmes of the European Space Agency. The unofficial nickname "vomit comet" became popular among those who experienced their operation.[2]