In your toilet at home, you probably are unconcerned with whether you get a good "seal" between your buttocks and the seat; so long as you are reasonably positioned . . . gravity alone prevents mishaps. Indeed, the hole is so large that for most of us -- even in this lard-butted society -- a "seal" is impossible. In the space toilet, however, a seal is ESSENTIAL. You see why, in zero gravity . . . So, just to make sure, NASA has installed little cameras inside the toilet bowl, looking up -- linked to a TV screen in front of you -- so you can check out the integrity of the seal, and make any necessary adjustments before poopage begins . . .
It would definitely be more difficult to be a successful astronaut if you have a flat butt. You need some padding there, to assure a seal.
Which is why… (ahem)
We should call them "asstronauts."Also, one of Weingarten's reader (I guess there's a few of them) writes, "When the unthinkable happens, when the space toilet-asstronaut seal is imperfect, the resulting free range pooplets have an official NASA name: Escapees."