The most interesting item of the collection is a lunar sample return bag (complete with lunar dust), used by Neil Armstrong to bring back the first moon rocks. Sotheby's says, "Nearly all of the equipment from that historic mission is housed in the US national collection at the Smithsonian. This is the only such artifact available for private ownership." It's estimated to sell for between $2 million and $4 million.

Many of these items come from the personal collections of the astronauts themselves, so there are some unexpected items up for grabs. Sure, there are the usual autographed photos and books, but there are also flight plans and charts, signed by astronauts, a small U.S. flag flown on Apollo 13 and a spacesuit thermal cover made for Gus Grissom. There's also hardware for sale: If you've ever wanted to own the computer processor of a Space Shuttle orbiter, this is your chance.

It'd be easy to make fun of this auction, but honestly there's a lot of really cool stuff in here for space enthusiasts. As for me, I have my eye on an autographed matted and framed photo of the Apollo 11 crew. Anyone have an extra $7,000 I can borrow?