A third crewmember will join the International Space Station today after the docking of the Space Shuttle Discovery. It will mark the first time since May 2003 that more than two long-duration crew members have called the orbiting laboratory home.
Discovery, with Commander Steve Lindsey, Pilot Mark Kelly and Mission Specialists Mike Fossum, Lisa Nowak, Stephanie Wilson, Piers Sellers and Thomas Reiter aboard, is scheduled to dock with the station at 9:52 a.m. CDT.
Shortly after the welcome by station Commander Pavel Vinogradov and NASA Science Officer Jeff Williams and a mandatory safety briefing, Reiter will transfer his seat liner to the Soyuz spacecraft attached to the station, making him an official station crewmember. Reiter is a European Space Agency astronaut from Germany, flying under a contract between ESA and the Russian Federal Space Agency.
During Discovery's approach to the station, Lindsey will pilot the shuttle on what amounts to a back flip, called the Rendezvous Pitch Maneuver. At about 600 feet below the station, the flip will give Vinogradov and Williams a chance to photograph the thermal protection tiles on the bottom of Discovery. Using digital cameras with 400mm and 800mm lenses, they will take a carefully planned series of photos of the shuttle's underside.
The images will be downlinked for study by experts on the ground, starting with the more detailed images from the 800mm lens. More 800mm photos will be taken than during Discovery's approach during STS-114. One increased photo emphasis will be looking for protruding gap fillers, like those removed by STS-114 spacewalker Steve Robinson last year.
These photos and other data, including images from more than 100 cameras on the ground, in aircraft and on the shuttle, as well as data from the shuttle arm and the Orbital Boom Sensor System (OBSS) attached to it, will be used, along with data from subsequent surveys, to make sure that Discovery sustained no major damage on launch, ascent and in orbit.
About three hours after docking, both crews get to work with more robotic operations to prepare for additional surveys. Nowak, Wilson and Williams will operate the space station robotic arm, Canadarm2, from inside the Destiny Lab.
They will use the arm to lift the OBSS from Discovery's payload bay sill and hand it over to the shuttle arm, operated by Lindsey and Fossum. Clearance restraints around the shuttle's docking mechanism do not allow the shuttle arm to grapple the boom on its own.
Transfer of cargo from the shuttle's middeck including spacesuits will begin shortly after docking. At least two spacewalks are scheduled, one on Saturday and another on Monday. A third may be done if the mission is extended a day.
Discovery's crew was awakened at 2:38 a.m. Thursday by "Daniel," performed by Elton John and dedicated to Reiter. The station crew was awakened at the same time by its standard wakeup tone.
The next STS-121 mission status report will be issued Thursday afternoon, or earlier if events warrant.
