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International Space Station Gains A Room In Galactic Home Addition

By | October 29, 2007

      Space Shuttle Discovery Heat Shield OK, Cleared For Reentry

      The International Space Station (ISS) is growing with the addition of a new room, a sort of connecting chamber that eventually will lead to new laboratories that will be added to the space station on future space shuttle flights.

      It’s all part of the years-long construction job of assembling a huge building while it whirls through the vacuum of space at 17,500 miles an hour.

      That Node 2 module, called Harmony, was lifted to the ISS by Space Shuttle Discovery, which launched from Kennedy Space Center last week.

      Separately, NASA experts and leaders finished examining Discovery for any damage to its heat tiles that might have occurred during liftoff and ascent to orbit, and pronounced the space shuttle in good shape, clearing it for reentry and landing at 4:50 a.m. ET Tuesday.

      There was concern that the Discovery orbiter vehicle thermal protection system might be damaged by ice that formed on the shuttle external fuel system, with worries that the ice might break loose and strike heat shielding on the orbiter vehicle.

      But that turned out not to be the case.

      Before launch, NASA also studied some degradation of protective coating on three reinforced carbon-carbon heat shield tiles on the leading edge of a Discovery orbiter wing, but once Discovery attained orbit, they found no cause for alarm there.

      The space agency is sensitive to any heat shielding problems on shuttle orbiter vehicles after foam insulation broke free from the external fuel tank and punched a hole in the leading edge of a wing on Space Shuttle Columbia in 2003, which led to disintegration of the spacecraft and loss of the crew during reentry.

      Arrival of the Harmony node at the space station is a milestone in its years-long construction in space.

      Installation of Harmony increases living and working space inside the station to approximately 500 cubic meters (18,000 cubic feet).

      It also allows the later addition of international laboratories from Europe and Japan to the station.

      Harmony will provide a passageway between three station science experiment facilities: the U.S. Destiny Laboratory, the Kibo Japanese Experiment Module, and the European Columbus Laboratory.

      As well, Harmony also provides connecting ports for Multi-Purpose Logistics Modules, the Japanese H II Transfer Vehicle and the Pressurized Mating Adapter 2 to which space shuttles dock.

      The Space Station Robotic Arm, Canadarm2, can operate from a powered grapple fixture on the exterior of Node 2. ?Under contract of the Italian Space Agency, Alenia Spazio in Turin, Italy, led a consortium of European sub-contractors to build the node.

      Harmony was built for NASA under a barter agreement with the European Space Agency in exchange for NASA launching the European Columbus Laboratory on the space shuttle to the International Space Station.

      Large and heavy, the Harmony node could be lifted to orbit only by a space shuttle. The aluminum node is 7.2 meters (23.6 feet) long and 4.4 meters (14.5 feet) in diameter. Its pressurized volume is 75.5 cubic meters (2,666 cubic feet), and its launch weight is approximately 14,288 kilograms (31,500 pounds).

      That’s equal to the weight of about six Humvees.

      Node 2 arrived at Kennedy Space Center, Fla. on June 1, 2003 to begin final preparations for its launch on shuttle mission STS-120, station assembly flight 10A. The name for Node 2, Harmony, was announced March 15 this year.

      Getting Harmony in place is just part of the daunting five-spacewalk challenge during the Discovery STS-120 Mission.

      Mission Specialist Scott Parazynski and Expedition 16 Flight Engineer Daniel Tani successfully completed the second spacewalk of the STS-120 mission yesterday.

      Parazynski and Tani completed preparations for relocation of the P6 truss segment early in the spacewalk.

      Mission Specialists Stephanie Wilson and Doug Wheelock used the station robotic arm to remove the P6. They placed the solar array section in a temporary holding position before handing it off to the shuttle robotic arm this morning.

      Tani performed a couple of inspections requested by mission managers. He photographed the handrail on the Crew and Equipment Translation Aid cart, but he did not note any apparent sharp edges. While inspecting a rotary joint used to rotate solar arrays he noticed metal shavings and unusual wear on a race ring. The joint has been showing some increased friction lately, and engineers are analyzing potential causes.

      The next spacewalk is scheduled to take place tomorrow, when Parazynski and Wheelock will team up to assist with robotic arm attachment of the P6 truss in its new location on P5.

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