Shuttle Endeavour's Heat Shield Cleared of Concerns

Shuttle Endeavour's Heat Shield Cleared of Concerns
The International Space Station's new Tranquility module is moved to the port side of the Unity node on the station during an overnight spacewalk that began Feb. 10, 2010 on NASA's STS-130 mission.
(Image: © NASA.)

The space shuttle Endeavour?s heat shield is in fineshape despite three minor defects, which pose no risk to the orbiter or itssix-astronaut crew, a top NASA official said Friday.

Deputy space shuttle program manager LeRoy Cain said engineershave cleared Endeavour for its planned re-entry and landing late next week aftersettling concerns over two protruding bits and a crackedthermal tile.

Images of Endeavour before it arrived at theInternational Space Station this week revealed a small ceramic insert juttingup from just below a cockpit window. A small crack in a white heat-resistanttile on the cockpit?s roof also had reappeared and part of a small seal on theshuttle?s left wing had peeled up.

None of the items posed a major safety concern, and allare too small to cause any damage to Endeavour if they rip off under thesearing heat of re-entry, said Cain, who leads Endeavour?s mission managementteam.

Cain told reporters that NASA engineers had ?reviewed allof that data and we determined that the vehicle is cleared for safe deorbit,re-entry and landing.?

NASA has kept a close watch on shuttle heat shield healthsince a piece of debris led to the destruction of shuttle Columbia duringre-entry in 2003. A final, standard inspection of Endeavour?s heat shield willbe conducted by shuttle astronauts once the orbiter leaves the station nextweek.

Tranquility in space

With Endeavour?s heat shield in the clear, all 11astronauts aboard the linked shuttleand space station can focus on opening the orbiting laboratory?s brand-new roomand fixing a finicky spacesuit fan for a late Saturday spacewalk.

The newspace room, called Tranquility in honor of the Apollo 11 landing site, wasattached to the station during an overnight spacewalk that began late Thursday.

The module is nearly 24 feet (7 meters) long and aboutthe size of a small bus. The plumbing lines for its main cooling system haven?tbeen hooked up yet, so astronauts can?t switch on all of its systems.

But they can open the hatch to the module and beginoutfitting it for use on the space station.

That grand opening is slated to take place tonight at9:14 p.m. EST (0214 Saturday GMT).

?Today we ingress the new module and get it up andrunning. Great to have everybody on board!? station commander Jeffrey Williamswrote in a Twitter update. He leads the station?s five-man crew.

The astronauts are expected to open Tranquility?s doorand move a bulky bench press-like exercise machine inside as one of their maintasks. They will have to use hand-held flashlights since the module?s mainsystems aren?t online.

Tranquility was delivered with a seven-window observationdeck that includes a huge round central window that is the largest ever sent tospace. ?Those windows are closed tight and covered by protective shutters, butwill be opened next week once the observation dome is moved to its final,Earth-facing location.

The two additions cost nearly $409 million and were builtin Italy for NASA by the European Space Agency. They?re arrival has brought the$100 billion space station up to 98 percent complete, but three spacewalks are requiredto fully install them.

The spacesuit glitch, the second for Endeavour?s two-man spacewalkingteam, will require astronaut Nicholas Patrick to fix a malfunctioning faninside his suit. He may replace the small parts or use a different suitentirely, but only after the power harness on that spare can be repaired,mission managers said.

Next shuttle?s move delayed

Meanwhile, engineers back on Earth have delayed plans tomove Endeavour?s sister ship Discovery to NASA?s cavernous Vehicle AssemblyBuilding in Florida to be attached to its external fuel tank and rocketboosters.

Frigid temperatures will keep that shuttle in itsmaintenance hangar at the Kennedy Space Center until at least Monday. Whentemperatures drop to around 30 degrees Fahrenheit (minus 1 degrees Celsius) theseals on a shuttle?s thrusters can leak, among other issues, Cain said.

Discovery is slated to launch a cargo pod filled withsupplies and equipment to the space station on March 18. It is one of NASA?sfive finalshuttle flights (including Endeavour?s current one) before thethree-orbiter fleet is retired this fall.

Cain said shuttle managers will wait to see if the coldsnap in Florida breaks next week before deciding what impact Discovery?sdelayed move, if any, will have on its upcoming launch date.

SPACE.com is providing complete coverage ofEndeavour's STS-130 mission to the International Space Station with ManagingEditor Tariq Malik and Staff Writer Clara Moskowitz based in New York. Click here for shuttle missionupdates and a link to NASA TV.

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