Discovery crew inspects space shuttle for damage

HOUSTON, July 5 (Reuters) Astronauts on shuttle Discovery began a painstaking inspection of their spacecraft today, using a sensor-laden robot arm to look for damage after launch from Florida on a mission critical to the shuttle program's future.

NASA executives earlier said flecks of insulating foam flew off the orbiter's problem-plagued fuel tank during yesterday's Fourth of July takeoff, but that Discovery looked to be in good shape.

The seven-member shuttle crew hopes to confirm that by poring over vulnerable areas such as wings and the nose cap with lasers and close-up cameras attached to the robot arm.

Television shots from the arm crept along as the sensors looked for nicks in the protective heat shield in a process expected to take more than six hours.

A 1.67 pound chunk of fuel tank foam was blamed for the Columbia disaster in 2003 after it slammed into the shuttle's wing heat shield at launch, which later caused the orbiter to break apart over Texas, killing the seven astronauts on board.

Potentially dangerous foam also flew off on a subsequent shuttle mission last summer, raising questions about whether the spacecraft NASA has flown since 1981 could still be operated safely enough to finish the half-completed 100 billion dollars International Space Station.

SAFETY UPGRADES NASA spent 1.3 billion dollars over the last three years to fix the fuel tank and make safety upgrades to the shuttle, which included the sensor system to look for damage. It was first used on last year's flight.

NASA managers warned before this flight that the tank, covered with more than 4,000 pounds of foam, would continue to shed debris, but expected no pieces large enough to harm the shuttle.

Shuttle program manager Wayne Hale said with one possible exception the foam pieces spotted yesterday were small, and only one appeared to strike the spacecraft. But he said the foam shook loose late enough in the launch that it appeared to hit with little force and posed no danger.

''I think the tank performed very, very well indeed, very pleased. As opposed to where we were last year, we saw nothing that gives us any kind of concern about the health of the crew or the vehicle or any cause to think we wouldn't be safe to fly the next tank,'' Hale said.

The agency needs a successful mission to resume space station construction, which has been on hold since the Columbia accident and will require 16 shuttle flights to complete.

Another accident or serious problem could ground the shuttle fleet permanently before its planned retirement in 2010.

Discovery is on its way to the space station, where NASA says astronauts could stay and wait for a rescue mission if dangerous damage is found.

The shuttle's 12-day mission is meant to test fuel tank repairs and deliver badly needed supplies and equipment to the space station. The astronauts will make at least two spacewalks.

One will test whether the robot arm and an extension, 100 feet long in total, can be used to maneuver spacewalkers to inaccessible parts of the shuttle for repairs.

During the second spacewalk, two astronauts will try to fix the space station's broken mobile transporter, which travels on tracks on the outside of the space station and will be needed to install trusses and solar arrays on the space station.

Damage to Columbia at launch went undetected until it disintegrated 16 days later as it flew back into the atmosphere from space. Superheated gases entered the breach in a wing heat shield and caused the spacecraft's destruction.

REUTERS SHB RK2028