14 DAY TRIAL // Astronauts aboard the International Space Station (ISS) and the STS-119 Discovery mission will have the rest of Tuesday off from chores, in order to be able to spend some time together, before the shuttle leaves tomorrow. With yesterday's third and final spacewalk complete to a partial success, there are no important tasks to be done on the station, and the mission has already been cataloged as without a glitch, following the seamless deployment of the last array of US-built solar wings on the ISS, on Friday.
The 13-day mission will be completed once Discovery touches down on Saturday at the Kennedy Space Center (KSC), in Florida. During re-entry, the craft will carry out another scientific experiment, designed to assess the state of the craft's heat shield, as well as to determine how air flows on its belly during descent. The hatch connecting the shuttle to the station will be sealed tomorrow, and then the visiting crew will power up their engines for their return home.
Discovery will also bring home ISS astronaut Sandra Magnus, who has been replaced on the station by the first long-term JAXA astronaut, Koichi Wakata. During the mission, the joint crew on the orbital facility, totaling 10 people, performed numerous chores designed to prepare it for the arrival of more occupants, in late May. The permanent crew aboard the ISS is to grow to six by mid 2009, and a rigorous test of all facilities has been absolutely necessary.
During the first spacewalk of the mission, astronauts used the robotic arms aboard the Discovery and the ISS in order to maneuver a 16-ton truss rod segment, which was attached to the “backbone” of the station and thus completed it. On its end, the rod had all the new solar wings, which were neatly folded like maps inside their hermetically sealed boxes. On Friday, they were successfully deployed, boosting the power output of the station by more than 25 percent.
During the second spacewalk, on Saturday, astronauts placed or replaced a number of scientific experiments to and from the outside of the ISS, and loosened the battery covers on some modules, so that future missions could access these locations more easily. Still, the spacewalkers were unable to deploy the cargo platforms, on account of a small pin that was stuck in the wrong position.
On Monday, the last extra-vehicular activity (EVA) attempted to fix this problem, but nothing could be done to unjam the pin. The Mission Control told the astronauts in the end to quit their attempts and to return to the safety of the station. Following today, the 7 astronauts aboard Discovery will seal the hatch between themselves and the ISS and will engage on the three-day trip back home.