Sunday, July 31 2005 10:25 Hrs (IST) - World Time -

Houston: Two 'Discovery' astronauts equipped with caulking guns, foam brushes and putty knives yesterday night (Jul 30, 2005) practiced repairs of deliberately damaged heat shields of their space shuttle in the mission's first spacewalk.

After depressurising an airlock between the shuttle and its open cargo bay, astronauts Soichi Noguchi and Stephen Robinson began their adventure at 1514 hrs (IST) as the International Space Station, with Discovery firmly docked into its shuttle bay, cruised about 361 kms above Central Asia.

The spacewalk lasted six-and-a-half hours and astronauts tested the repair techniques developed after the 'Columbia' tragedy in which India-born Kalpana Chawla and six other astronauts lost their lives.

Officials at the Johnson Space Center here congratulated the astronauts on completion of the spacewalk, the first of the three planned for the mission.

With the future space flights grounded, NASA has also sought to extend the Discovery mission by a day.

The extra time would allow astronauts to remove more old or broken equipment from the space station.

It was all valuable feedback; engineers wanted to see how their creations fared in the weightlessness of space for possible future use in an emergency, said Cindy Begley, the lead spacewalk officer.

Columbia's astronauts had no such tools or techniques at their disposal. Of course, neither they nor flight controllers knew Columbia had a gaping hole in the left wing, left there by a 75 gram chunk of fuel-tank foam insulation that broke loose at launch.