Well, actually, they can. Not your spleen per se, but one's workings in inner space become public knowledge when inside the closed-environment confines of tin box containers floating in outer space.
Lest one doubt the powers of the organ in question, let me remind you of flatulence's true power, courtesy of "The Spleen," one of the best characters amongst the many colorful ones who appeared in the much-underrated movie Mystery Men:
Mystery Men - The Spleen. - The funniest videos are a click away
Now that I hear the Korean space program has approved kim chi for space, I am a bit concerned. Sure, they made sure it's free from the germs key to its fermentation in the bottle, but have they thought about the deadly "ferment" that gives "The Spleen" his peculiar powers? Have they thought about what many Koreans all know, but aren't talking about, namely the potent punch of the "kim chi fart" or its more deadly and disgusting cousin, the dreaded "kim chi burp?"
Unless you have had an older Korean man fresh off a full meal of kim chi burp in say, the same car as you, you don't know the true horror of smelling kim-chi-in-the-gut re-presented for your olfactory pleasure. But in even in the enclosed space of a taxi in the dead of winter, you can still crack a window.
Whatcha gonna do on the International Space Station?
Please don't misunderstand – I love kim chi and eat it nearly every day. I live in Korea.
However, people on the inside here – Koreans and non-Koreans alike – we know that after a meal of rice, kim chi, and a little red meat, the hot gases of Venus ain't nothing. I bet NASA hasn't measured those in any tests.
I'm not saying this to ridicule; I am saying this because I don't want to see Ko San being flushed out an airlock, Sigourney Weaver style.