Oh, how the times have changed... its final mission saw Atlantis successfully deliver the Russian Mini-Research Module Rassvet to the ISS. She'll be prepped one last time to stand-by as a rescue ship for the upcoming (and final) missions of Endeavor and Discovery, but Atlantis' days in space are likely over.

ENGADGET: Space Shuttle Atlantis ends its run of predicting disaster for other NASA shuttles

Endeavour, along with Discovery, Enterprise and Atlantis, became a museum piece after NASA ended its 30-year shuttle program in July 2011.

CNN: Space shuttle Endeavour's final touchdown

Well, if they get back to flying Atlantis and if they get back to flying Atlantis in September, which they dearly would like to do, they have to get the Discovery ready because the new rules say you have to have another shuttle ready to fly as a rescue mission.

NPR: Shuttle Landing Delayed Due to Poor Weather