^* On a parabolic flight, evasive maneuvers are critical. Joe McMann, who used to run NASA’s EVA Management Office, told me he was once flying with a man who threw up very abruptly. “I realized that in about three seconds, that vomit is going to come down on me in 2 G’s. I was doing all kind of motions to get out of the way.” One NASA employee I met swears double gravity makes it harder to throw up.