Spacewalker Stephen Robinson gently plucked two strips of protruding heat shielding from the bottom of the space shuttle Discovery, completing the first-ever in-flight shuttle repair with fingertip ease.

Cameras operating from the shuttle's sensor boom and from Robinson's helmet provided spectacular views of his historic journey on Wednesday, as he first swooped out from Discovery's side on the end of a 55-foot crane, then curled beneath the orbiter to find and remove the two "gap fillers."

Intact, the two gap fillers could have led to potentially hazardous hot spots on Discovery's underside during reentry.

Officials were also worried about a frayed and billowing piece of thermal "blanket" that had started to come loose below the port side window where mission commander Eileen Collins will sit when she brings the shuttle home. But Thursday they decided that there is no need for a spacewalk to repair it and that the shuttle is ready to return Monday.

The blanket is not a heat hazard, as reentry temperatures on top of the shuttle never come close to the 2,300 degrees Fahrenheit that the underside must endure. What engineers were worried about was that a swatch of blanket may tear away during reentry and cause damage.

The thermal blanket, like the offending gap fillers and several large pieces of foam insulation that broke away from Discovery's external fuel tank during liftoff, were launch casualties that NASA tried hard to eliminate after the Columbia disaster grounded the fleet for 21/2 years.

Failure to resolve these, especially the shedding of foam debris, has prompted NASA to ground the fleet again while engineers figure out what went wrong and try to fix it. Officials have said that NASA must resolve the foam and gap filler problems before the shuttle flies again.

-- Guy Gugliotta

Astronaut Stephen Robinson photographed this image of the nose of the space shuttle Discovery, at the international space station, during his spacewalk.