vomit comet
noun
informal an aircraft that dives suddenly in altitude, simulating freefall, in order to allow astronauts to experience the nausea that can affect people in a gravity-free environment
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012