Endeavour astronauts Mike Fincke and Greg Chamitoff completed the primary task of the final mission spacewalk early Friday, the latching of the shuttle’s 50-foot-long Orbiter Boom Sensor System onto the solar power truss of the International Space Station.
The boom, developed in the aftermath of the 2003 shuttle Columbia tragedy to scan orbiter heat shielding for post launch and pre-landing debris impact damage, will fill a new role.The OBSS will serve as an extension of the station’s 58-foot-long robot arm to position spacewalking astronauts in hard to reach areas of the orbiting science lab for repairs. Former astronaut Scott Parazynski demonstrated the value of the extension during a late 2007 spacewalk in which he repaired a torn port side solar panel.
Endeavour's crew moves the Canadian Orbiter Boom Sensor System into place on the International Space Station's solar power truss. Photo Credit/NASA TV
Endeavour’s STS-134 mission is the 19-year-old orbiter’s final flight. The shuttle crew completed their pre-landing heat shield inspection with the OBSS early Thursday.
Fincke and Chamitoff began their 6½-hour spacewalk at 12:15 a.m., EDT, a half-hour early. The boom was moved from Endeavour’s cargo bay and latched into place on the station’s truss at 1:42 a.m. The transfer was carried out using both the shuttle and station robot arms.
The outing’s final tasks included the installation of a power data and grapple assembly on the OBSS, a fixture that will allow the long boom to be gripped by the station’s robot arm at the end as well as the mid-point.
The spacewalkers intended to wrap up their excursion at Express Logistics Carrier-3, a platform holding spare parts for the station’s thermal control, communications and robotics systems. Endeavour’s astronauts transferred the ELC-3 platform from the shuttle’s cargo bay to the station on May 18.Fincke and Chamitoff were to loosen several restraint bolts securing a spare arm for DEXTRE. DEXTRE is a hand-like extension of the Canadian developed robot arm that can carry out some maintenance work that would otherwise be assigned to spacewalkers.
Endeavour’s six astronauts are scheduled to depart the station late Sunday. The 16-day fight to equip the station with the Alpha Magnetic Spectrometer and external spare parts is slated to end Wednesday with a pre-dawn landing at the Kennedy Space Center.
Prior to the conclusion of Friday's outing, NASA will surpass 1,000 hours of accumulated time on spacewalks devoted to the assembly and maintenance of the space station.
Friday’s was the 159th of the spacewalks. Endeavour’s crew logged four of the spacewalks. Assembly of the space station began in 1998.