The “Vomit Comet” is the nickname of NASA’s microgravity aircraft. Officially named the Weightless Wonder, this plane achieves a feeling of weightlessness by flying a series of parabolas. Weightlessness begins during the ascent and continues over the top of the parabola. When the feeling of a downward force returns during the descent of the parabola, it rapidly increases until it’s nearly twice the force of gravity. This results in about twenty seconds of microgravity and twenty seconds of 2-g forces for each parabola. There are also about five to ten seconds for transition on each parabola.
While some people do experience motion sickness during the flight, it is more likely caused from the intense 2-g sections of the flight than the microgravity sections. Excessive head movement during these “heavy gravity” portions of the flight is a main culprit for making some flyers ill. However, the human body is able to adapt very rapidly, allowing experienced crew members of the Weightless Wonder to walk and move freely during the 2-g maneuvers when inexperienced flyers cannot.