STS-122 is the current NASA Space Shuttle mission to the International Space Station (ISS). It is being flown by Space Shuttle Atlantis. STS-122 marks the 24th shuttle mission to the ISS, and the 121st space shuttle flight since STS-1.The primary objective of STS-122 is to deliver the Columbus science laboratory, built by the European Space Agency (ESA), to the station. It will also return Expedition 16 Flight Engineer Daniel M. Tani to Earth. Tani will be replaced on Expedition 16 by Léopold Eyharts, a French Flight Engineer representing ESA. STS-122 will mark the final scheduled visit by Atlantis to the International Space Station. After Atlantis lands, the orbiter will be prepared for STS-125, the final servicing mission for the Hubble Space Telescope.
The completion of STS-122 will leave ten flights remaining in the Space Shuttle program until its end in 2010, excluding two as-yet-unconfirmed Contingency Logistic Flights.The original target launch date for STS-122 was December 6, but due to engine cutoff sensor (ECO) reading errors, the launch was postponed to December 9, 2007. During the second launch attempt, the sensors failed again, and the launch was halted.
A tanking test on December 18 revealed the probable cause to lie with a connector between the external tank and the shuttle. The connector was replaced and the shuttle launched during the third attempt on February 7, 2008.
