|MadSci Network: Astronomy|
Felt pens would work in outer space better than they do upside down on earth, but only noticeably so. In fact there is gravity up there, which is why the shuttle has to maintain such high speeds, so that it does not come falling back to earth. Think of riding a roller coaster and the sense of weightlessness you experience as you go up down rather quickly in short spurts: Or, as you begin to descend on a fast elevator. Those first few feet can actually make your hair raise a bit. Recall the old space lab as it came crashing to earth a few years back. Everything that goes up has to come down somewhere and sometime. Run some gravity searches on Google, etc. and you will be pleasantly surprised.
Thanks for the question
[Moderator's note: This webpage, a teaching activity on pens in space, also claims that felt pens should work OK in weightlessness. Maybe they weren't used on space missions because of their tendency to dry out?]
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