|MadSci Network: Astronomy|
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?
Try the links in the MadSci Library for more information on Astronomy.