Discovery Commander Mark Kelly guided the shuttle, carrying the main module of the Japan Aerospace Exploration Agency's Kibo lab, to a docking with the station as the two spacecraft flew 210 miles above the South Pacific. Before closing the final six hundred feet to the station, Kelly flew the shuttle through a slow backflip, allowing the station’s Expedition 17 Commander Sergei Volkov and Flight Engineer Garrett Reisman to take photos that ground experts will review to assess the health of Discovery’s heat shield.
Discovery also brought astronaut Greg Chamitoff to the station, who officially took over for Reisman as a member of the station crew at 5:35 p.m. when Chamitoff confirmed his custom Soyuz seatliner was installed. Reisman – now formally a mission specialist aboard the shuttle – will return home after more than three months on the station.
The shuttle and station crews opened hatches and greeted one another at 2:36 p.m. beginning nine days of joint operations between the astronauts and cosmonauts. Discovery mission specialists Mike Fossum and Ron Garan began an overnight "campout" in the station's Quest airlock pressurized slightly lower than the rest of the station and shuttle to prepare themselves for the mission's first spacewalk set to begin at about 10:32 a.m. Tuesday.
Sleeping overnight at the lower pressure significantly reduces the amount of time they must breathe pure oxygen Tuesday morning as they prepare for the spacewalk. The measure prevents decompression sickness as they operate in the low pressure of spacesuits to begin their work outside.
The 6˝ hour spacewalk by Fossum and Garan will prepare the Kibo lab for installation on the station and assist with transfer of the Orbiter Boom Sensor System back to the shuttle from the station, where it has been stored since the last shuttle visit. The two also will demonstrate a technique that may be used to clean debris from the station solar alpha rotary joint, which has known debris degrading its operation.
The 10 crewmembers will go to sleep about 9 p.m. Monday and receive a wakeup call from Mission Control at 5:32 a.m. Tuesday.