Mission Atlantis: Astronauts Scan Shuttle Heat Shield for Damage

CAPE CANAVERAL, Fla. - Astronauts aboard NASA's space shuttle Atlantis once morescanned their spacecraft's heat shield Monday, this time in search of any signsof strikes by micrometeoritesor orbital debris (MMOD).

STS-115shuttle pilot Chris Ferguson wielded Atlantis' 100-foot (30-meter) assemblyof a robotic arm and sensor-laden inspection boom to hunt for potential damagealong the shuttle's wing leading edges and nose cap, areas that see the highesttemperatures during reentry.

"If you look at the cumulative riskswe take in flight, MMOD risks is not insignificant," Phil Engelhauf, NASA's chief of the flight directors office, said Sunday of the micrometeoriteand orbital debris hazard to space shuttles in flight. "[But] it is not at thehighest end of the scale."

Atlantis' heat shield has alreadybeen clearedfor reentry based on studies of imagery taken during itsSept. 9 launch, a similar FlightDay 2 inspection, and a photographic survey taken by astronautsaboard the InternationalSpace Station (ISS) prior to the shuttle's Sept. 11docking.

Paul Dye, NASA's lead shuttle flightdirector for Atlantis' STS-115mission, said Saturday that anytime a spacecraft flies in orbit, there is arisk it could be struck by natural or man-made orbital debris.

"It is a small risk," Dye said."We've taken very few hits. We take the occasional hit, and it's something wethink that, since we have the time, it's prudent to go take a look at."

Atlantis mission specialists DanielBurbank and StevenMacLean are aiding Ferguson'sheat shield scan - known as a late inspection - which was first performed onNASA's STS-121shuttle flight aboard Discovery in July.

During that flight, astronautsactually beganthe late inspection while still docked at the ISS, but the crew - andmission controllers - foundthat the task ran long because of additional procedures and clearanceissues associated with using a 100-foot (30-foot) robotic arm combination inclose proximity with the ISS.

"It wound up taking quite a bitlonger to run the procedure because they had to take a lot more care and kindof depart from the rehearsed procedures," Engelhauf said of the STS-121late inspection, adding that shifting the scan to post-undocking forSTS-115 was an easy trade on crew time and energy. "We think it'll go faster,it'll be less stressful for the crew and just makes it easier all around."

Atlantis' STS-115 mission hasdelivered a $372million, 17.5-ton pair of trusses and new solararrays to the ISS in NASA's first dedicated space station constructionflight since the 2003 Columbiaaccident. The shuttle undockedfrom the orbital laboratory early Sunday after jump starting what NASA expectsto be fourmore years of ISS construction.

NASA roused Atlantis' crew todaywith John Denver's "Rocky Mountain High," a song chosen for STS-115mission specialist Joseph Tanner by his wife Martha.

"So good morning, Houston," Tanner said. "And we just flew overColoradoyesterday. It was beautiful [and] looked like a great place to live. And thankyou, Martha. The next few years are gonna be prettyexciting."

Water dump interruption

Atlantis' heat shield inspection waspaused intermittently as the STS-115 crew eyed a glitch with the orbiter'swaste water dump system.

Earlier today, shuttlecommander Brent Jett reported seeing a sort of burping action from anexterior nozzle that vents waste and extra water overboard, NASA commentatorKelly Humphries said.

The glitch was not expected to posea great concern for Atlantis, though mission controllers want to ensure the extrawater did not freeze into ice along the nozzle area and pose a debris hazardlater in the shuttle's flight, he added.

After more troubleshooting work byflight controllers on Earth and the STS-115 crew - which included clearing outthe pump nozzle of any water using air - the matter was resolved.

"We're going to continue to monitorthe [temperatures] to make sure that no ice forms," NASA astronaut MeganMcArthur, serving as spacecraft communicator, told Jett.

Meanwhile, STS-115mission specialists Heidemarie Stefanyshyn-Piperworked with Jett and others to ready Atlantis for its Sept. 20 landing.

12 people on orbit

While Atlantis headed for a waypointabout 70 nautical (129 kilometers) behind the ISS - where its crew will awaitanalysis of today's heat shield inspection - the shuttle's orbital neighborhoodgot a bit more crowded.

At 12:09 a.m. EDT (0409 GMT) today,two professional astronauts and one private spaceflyerrocketedspaceward atop a Russian Soyuz rocket on a two-daytrek towards the ISS. Aboard are Expedition14 commander MichaelLopez-Alegria, flight engineer - and Soyuzcommander - MikhailTyurin and U.S.entrepreneur Anousheh Ansari, who became the firstfemale space tourist with the successful launch.

The Soyuz is currently about 720miles (1,158 kilometers) ahead of the ISS but chasing the station from behind,leaving about 18,000 miles (28,968 kilometers) of forward flight before itcatches up with the orbital laboratory, NASA said.

The space shot brings the number ofhumans currently in Earth orbit to an even dozen: three on Soyuz, six aboardAtlantis, and the three-astronautcrew of Expedition 13 aboard the ISS.

"It really shows you how well we'vereally come together as a team," said NASA associate administrator for spaceoperations William Gerstenmaier of the international partnership that allowedsuch a feat during a NASA TV interview at the Soyuz's Baikonur Cosmodrome launch site in Kazakhstan. "This is trulyamazing."

The Soyuz TMA-9 spacecraft withAnsari and the Expedition 14 crew will dock at the ISS on Sept. 20, just a fewshort hours before Atlantis is expected to land at NASA's Kennedy Space Center, now slated for5:57 a.m. EDT (0957 GMT). The space station's current Expedition13 crew must also jettison an unmannedRussian cargo ship Monday night before the Soyuz docks.

"It's like some sort of intricateballet," NASA associate administrator Rex Gevedensaid in the taped NASA TV interview. "It's a daunting thing to do."

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• Image Gallery: Anousheh Ansari Prepares for Launch
• Complete Space Shuttle Mission Coverage
• NASA's STS-115: Shuttle Atlantis to Jump Start ISS Construction
• The Great Space Quiz: Space Shuttle Countdown
• Full Coverage: ISS Expedition 14