NASA postponed Atlantis' scheduled return to Earth when the Shuttle's cargo bay camera suddenly spotted a UFO (no, not E.T.) as apparently, there was an unidentified floating object outside of the shuttle. Atlantis was originally scheduled to land Wednesday, if it weren't for bad weather that made it risky, so the landing was postponed to Thursday.

But before the Shuttle can kiss terra firma, on Thursday astronauts and ground-based engineers alike will first have to answer a few questions, beginning with "What the heck was that thing floating outside Atlantis?" and "If it's part of Atlantis, can we land safely without it?".

NASA engineers theorize that "the thing" - if it was part of Atlantis - might have shaken loose while the crew was doing some pre-landing thruster and flight control systems checks. This has sent the crew, as well as the Air Force Space Command, scrambling to locate, detect, and identify the object. None of the Air Force's radar or telescopes have been able to locate the unidentified object.

NASA is sufficiently worried that the Shuttle crew has made an unprecedented three inspections of the Shuttle's heat shield using their robotic arm camera. Any breach in the heat shield would potentially be fatal to Atlantis and her crew, as what had happened to her sister Columbia. The second inspection didn't reveal any damage, but perhaps one can't be too sure in this business.

Atlantis has enough supplies to stay up until Sunday, but in a worst-case scenario, the Shuttle returns to the ISS where the crew will await a second Shuttle to pick them up.