The decision to pursue additional inspections was made this morning after video from cameras aboard the shuttle showed a piece of debris in close proximity to the vehicle.
Also, the weather forecast for a landing on Wednesday had called for poor conditions, and Atlantis has plentiful supplies aboard to allow multiple landing attempts as late as Saturday. Atlantis is now aimed toward a landing on Thursday at NASA's Kennedy Space Center, Florida.
Engineers are concerned the debris seen could be something that came loose from Atlantis. They will use the extra time to verify the shuttle is in good shape for the trip home.
Atlantis' crew -- Commander Brent Jett, Pilot Chris Ferguson and mission specialists Joe Tanner, Dan Burbank, Heidemarie Stefanyshyn-Piper and Canadian Space Agency astronaut Steve MacLean -- will use the shuttle's robotic arm on Wednesday to inspect the spacecraft. The crew began a sleep period at 12:45 p.m. CDT today and will awaken at 8:45 p.m. CDT. Before going to sleep, the crew positioned the arm above the payload bay, and Mission Control has used its cameras to survey the top side of the shuttle. The cameras on the robotic arm will later be used by the crew to inspect areas on the underside of Atlantis.
Atlantis' primary landing opportunity to Kennedy on Thursday begins with a deorbit engine firing at 4:14 am. CDT and culminates in a touchdown at 5:22 a.m. CDT.
Meanwhile, the International Space Station's next crew, Expedition 14 Commander Mike Lopez-Alegria and Soyuz Commander and Flight Engineer Mikhail Tyurin are closing in on the complex. With them is Spaceflight Participant Anousheh Ansari, a U.S. businesswoman who will spend eight days on the station under a commercial agreement with the Russian Federal Space Agency. They will dock their Soyuz spacecraft to the station at 12:24 a.m. CDT Wednesday.
Aboard the station, Expedition 13 Commander Pavel Vinogradov, Flight Engineer and NASA Science Officer Jeff Williams and Flight Engineer Thomas Reiter, a European Space Agency astronaut, will open hatches to greet their new arrivals at 3:10 a.m. CDT Wednesday. The station crew spent some additional time earlier today gathering data on the Elektron oxygen generating system's overheating malfunction. Russian engineers are continuing to evaluate the system's malfunction and future repairs. Repair work is not planned to be performed while the crew hands over operations of the complex to Expedition 14. Oxygen supplies on the station are plentiful, and the cabin air will be refreshed using oxygen canisters and tanks until the Elektron is repaired.