14 Mar 2009, 0602 hrs IST, AFP


WASHINGTON: NASA on Friday appeared likely to make a new attempt to launch the space shuttle Discovery on Sunday even if the cause of the hydrogen leak that delayed its mission this week remains unknown.

"We are prepared if we found nothing to go ahead, reassemble, reconnect and get back into a launch configuration," Mike Leinbach, the launch director, told reporters at a briefing.

Technical crews were replacing parts and running precautionary checks and other tests early Friday at the site where the leak took place Wednesday scrubbing the launch for the International Space Station (ISS) planned for that day, and everything looked fine, he said.

The leak was detected when the external fuel tank was 98 percent full of liquid hydrogen stored at an ultra-low temperature. The tank had to be emptied again for the checks to be carried out.

"Once we did get in we did a very detailed measurement ... all the measurements turned out fine. Then we went to a standard leak check ... at ambient conditions, we saw no leak, which is what we were expecting," Leinbach said.

"And then we disconnect the ordinance ... We don't have any smoking gun yet. We did see one seal that may have a slit; I am not sure if it is the cause of the issue yet. You have to give us another six, to eight hours before we can declare that the culprit or not.

"We are going to change all the components in that system as we plan to do whether we found any issue or not and get back to a launch configuration."

NASA officials will meet again on Saturday at 1:00 pm (1700 GMT) to review the repairs and decide whether to give the green light for a launch on Sunday.

If the same leak occurs again, then the launch will be scrubbed again, Leinbach said. If everything is normal, then the first leak will be seen as an unexplained abnormality, he said.

The tank should be filled in an operation starting at 10:18 am (1418 GMT) Sunday. Launch was scheduled for 19:43 pm (2343 GMT) with a 10-minute window for blastoff, Leinbach said.

NASA has until Tuesday to launch the shuttle in order not to hamper a Russian Soyuz mission to the ISS that is due to lift off on March 26, as two spacecraft cannot dock at the space station at once.

If Discovery is unable to launch by Tuesday, then its mission will be delayed until April, which will also put back other shuttle flights due in May to repair and maintain the Hubble telescope.

The Discovery and its crew of seven are due to deliver and install a fourth pair of solar panels to the International Space Station.

The panels are to supply power for onboard laboratories and more power for the station's crew, which will double from three to six in May.

Discovery's astronauts include Koichi Wakata of the Japan Aerospace Exploration Agency, who is to become the first Japanese station crew member.