With just 17 or so flights left on the shuttle manifest before the program is terminated in 2010, NASA's three remaining orbiters can only expect to fly about five missions each. As it turns out, NASA now plans to retire Atlantis in 2008, after five flights, rather than put it through a required overhaul and to "fly out" the remaining half-dozen missions on the manifest with Discovery and Endeavour.

First flown in 1985, shuttle Atlantis is expected to be retired from service in 2008. Credit: NASA

But shuttle program manager Wayne Hale told Kennedy Space Center employees today that Atlantis will not be given to a museum, at least not right away. Instead, the space shuttle will be used for spare parts to help keep Discovery and Endeavour healthy through the end of the program.

"Atlantis will be coming due for an OMDP (orbiter maintenance down period) in the '08 time frame," Hale said. "And we looked the manifest and laid it out and we believe we can fly the '08, '09 and '10 time frame with Discovery and Endeavour.

"Discovery just came out of OMDP and Endeavour is just about to come out of OMDP. So it looks like the right thing to do is not to put Atlantis through another OMDP, which would get it ready to go fly maybe just at the very end, in 2010, but rather use it was a parts donor, if that's the word, for the other vehicles.

"So we're going to try to keep it in as near flight ready condition as we can without putting it through an OMDP so we can use those parts," Hale said. "Quite frankly, people are already calling us and asking us can they display one of our orbiters in their museum after we're done with it. I'm not giving anybody anything until we're all agreed the station is complete and the shuttle's job is done. In the sense that we're talking about mothballing, I'm not sure that's the term I'd use."

All shuttles are required to undergo periodic inspections and modifications to maintain their overall health. Such OMDP overhauls can take a year or more to complete.