Repairs, Spares Set For Space Station
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By Frank Morring, Jr.
Two spacewalkers are outside the International Space Station (ISS) July 20 to install some large spare parts delivered by the space shuttle Endeavour against the day the shuttles will no longer be flying.
Meanwhile, inside the station Expedition 20 commander Geddany Padalka and flight engineer Frank De Winne are repairing one of the three toilets available to the 13 travelers in the two docked vehicles.
Astronauts Dave Wolf and Tom Marshburn will go to an integrated cargo carrier (ICC) that arrived on Endeavour to collect the spares and mount them on an external stowage platform on the truss for later use. The spare parts - a space-to-ground antenna, coolant pump and motor/transmission combo for the mobile transporter - all are too large to be delivered on any vehicles that will be visiting the station after the shuttles retire next year, and NASA wants to pre-position them in case they are needed after that.
On July 19 the crews used the shuttle and station robotic arms to get the ICC out of Endeavour's payload bay and install it on the station's mobile transporter, which will move up and down the truss delivering hardware to spacewalkers on the next three extravehicular activities (EVAs) of the STS-127 mission.
The work went ahead because the shuttle and station robotic arms weren't needed for a focused inspection of the orbiter's heat shield, which had tentatively been scheduled for July 19. On July 18 the mission management team (MMT) decided that none of the damage detected with the extensive photography and on-orbit laser-sensor inspections that are now standard during and after shuttle ascents was serious enough to warrant a second look.
Mike Moses, the MMT co-chair, said July 18 that the thermal protection system had not yet been cleared for re-entry, but he expected that action to follow once the remaining analysis was completed. Earlier July 18, spacewalkers Wolf and Tim Kopra worked closely with four of their colleagues at robotics stations inside to get the final element of Japan's Kibo laboratory module in place.
In the first extravehicular activity (EVA) of the mission, the two spacewalkers moved quickly to prepare Kibo and its exposed facility for the installation, separating from one another as soon as they left the airlock to remove insulation from the attach points on the end of the laboratory and the exposed facility.
While Kopra and Wolf moved on to other tasks, Japan's Koichi Wakata and Doug Hurley of NASA drove the station arm from the robotics work station inside the station's Destiny lab module to lift the exposed facility - essentially a porch where experiment packages can be operated in open space - from the orbiter's payload bay.
To get it from there to its final position, Wakata and Hurley handed off the 9,000-pound unit off to the shuttle arm, operated from inside the space shuttle Endeavour by STS-127 commander Mark Polansky and Canadian astronaut Julie Payette. While Polansky and Payette used the shuttle arm to hold the exposed facility, the station robotics team operated the grapple fixtures at both ends of the station arm to inchworm it into a position where it could reach the end of Kibo. Then Payette and Polansky handed the exposed facility back to the station arm, which slowly moved it into position at the end of Kibo.
Japanese controllers later were able to activate the exposed facility, and declared Kibo - the largest laboratory on the ISS - completed.
The only serious problem so far on the mission is a toilet failure in the U.S. Destiny lab. About six liters of pre-treated waste water flooded the separator pump, which adds chemicals that help separate solid from liquid waste. Padalka and De Winne wore protective gear for the two-and-a-half-hour job replacing contaminated internal parts in the system July 20. In the meantime, the combined crews will use the toilets in the Russian service module and the orbiter.
Endeavour photo: NASA
