Subject: Do felt pens work in outer space?

I've heard that NASA spent a lot of time and money developing a 'space pen', 
but can't find any details about why normal pens don't work. Asking around, 
some people think felt pens need gravity (I know biros do), but I can write 
upside down with my felt pens. Although they dry out if you leave them with 
the tip upwards, I think this is because gravity pulls the ink away from the 
tip. In space, gravity wouldn't pull the ink anywhere, so this would be more 
akin to storing felt pens flat on earth. They can be stored for years like 
that. And I think felt pens work by 'capillary' action - i.e. when the tip 
touches the paper, the ink 'leaks' onto the paper. Again, this wouldn't need 
gravity. But, presumably, NASA know all this better than me, so I must be 
wrong. Which part of the above is wrong, and why?

Re: Do felt pens work in outer space?