Astronauts Mark and Scott Kelly - who are identical twin brothers - are sharing via Twitter what it is like to be fellow space commanders, and they may even meet each other in orbit next year.
The spaceflying brothers are each gearing up to command different spacecraft: Mark is preparing to take the helm of NASA's STS-134 shuttle mission, while Scott will lead the International Space Station's Expedition 26 crew. Both missions are slated to launch for 2010.
If the current schedule holds, the two may meet in space - an orbital first - during their respective commands next summer. In the meantime, the Kelly brothers are undergoing rigorous training - Mark mainly from Houston, and Scott from Houston, as well as Tsukuba, Japan, and Star City, Russia, and other countries where station crews train.
Like some other astronauts, the Kelly brothers are documenting their spaceflight training on Twitter. Mark Kelly writes under the name ShuttleCDRKelly.
"About to cram myself into the EMU for 6 hours underwater," he wrote last week, describing the spacewalk training astronauts undergo in a giant swimming pool to approximate the effects of microgravity.
Scott Kelly posts as StationCDRKelly. He recently returned from a trip to Japan to train at the Japanese Aerospace Exploration Agency, which commands the station's giant Kibo module.
"We have a great relationship with our intl partners - one of the many things that make this a great program," he tweeted recently.
The twins join a cadre of other spaceflyers sharing the experience of being a professional astronaut via the social microblogging site. Currently, four twittering people are in space: space shuttle Discovery crewmembers Christer Fuglesang (CFuglesang), Jose Hernandez (Astro_Jose), and Tim Kopra (Astro_Tim), and station crewmember Nicole Stott (Astro_Nicole). With the exception of Fuglesang, who posted Twitter updates until launch, all of the astronauts are either tweeting from space or plan to during their mission.
Hernandez is posting his tweets in Spanish and English, while Fuglesang translated his into his native Swedish. The public can even use Twitter to spot the space station when it flies overhead.
But the Kelly brothers are the first sibling astronauts to embrace the medium to reach out to the public. They grew up in West Orange, N.J., and both joined the NASA astronaut corps in 1996. Each is a Navy captain, and both have served as space shuttle commanders before.
Mark has three space shuttle flights under his belt, including the STS-124 flight of Discovery in 2008, which he commanded.
Scott is a veteran of two space shuttle flights, including the STS-118 mission of Endeavour in 2007, which he commanded. He is slated to spend about six months aboard the station for his upcoming mission.
Scott Kelly's Twitter updates can be found here: http://twitter.com/stationcdrkelly.
Mark Kelly's Twitter updates are here: http://twitter.com/shuttlecdrkelly.