The iPods have to be modified to use space flight-approved alkaline AA batteries, though. Li-ion batteries are currently not approved for space, surely due to the possible safety issues with Li-ion batteries; the last thing Apple needs is PR about an iPod exploding on the Space Shuttle. But at least Shuttle astronauts can use iPods at all—they aren't approved for use on the International Space Station.

Make you wonder about their playlists:

Can you hear me Major Tom . . .

On a clear day, you can see forever . . .