Space watches are the ultimate sport watches, aren’t they? Forget deep-sea diving, flying fighter jets, or hauling up the world's tallest mountains; there's nothing like rocketing past the atmosphere that captures the mix of nerdiness and machismo that attracts watch collectors. Just over 500 people have left the earth and come back, and Christie's is giving a true fanboy a chance to own one of their watches.

As part of its latest online-only watch auction, Rare Omega Watches, Christie's is offering this Speedmaster X-33, worn by Russian Cosmonaut Sergei Zalyotin on multiple missions at the turn of the century. While traditionally NASA and a few other space agencies used the Omega Speedmaster Professional as their mechanical timekeeper of choice, the thought was that by 1995 technology had come far enough that the decades-old chronograph was outdated and no longer the best tool. So Omega was asked to come up with a successor and what we got was the strange X-33.

First, the X-33 is an electronic quartz watch, making it more accurate than a mechanical watch. The 41mm case is made from titanium to reduce weight and increase strength, and the dial is a hybrid of analog and digital displays. The basic time display still uses hands but the chronograph and alarm functions utilize the LCD screen to simplify the dial. The crown also adjusts functions with a series of presses, which is supposed to make it easier to use with space gear on. In addition to being used by astronauts and cosmonauts, the X-33 was often issued to military test pilots as well.

Zalyotin was given this particular X-33 by the Russian Federal Space Agency in 2000 and he wore it that year on a mission to the Mir space station as well as on later missions to the International Space Station. According to Christie's, this is the only wristwatch to have ever been worn on both space stations. The watch is being sold by a collector who purchased it directly from Zalyotin and included with the box, papers, and accessories are two signed photographs of the cosmonaut himself.

It's been a big year for space-worn watches selling publicly. Usually, because the watches worn by astronauts, cosmonauts, and other space travelers are equipment issued by space agencies, they remain in government hands forever. But when they do make it to public markets, prices are appropriately high. In December, Christie's sold a Speedmaster that flew to the moon on Apollo 17 for nearly a quarter-million dollars, and just a few months before that a Bulova chronograph actually worn on the lunar surface fetched over $1 million.

This Omega Speedmaster X-33 is part of Christie's online- only Rare Omega Watches auction, which runs from Jan. 28 through Feb. 9. The estimate for this watch is $10,000 to $20,000.