NASA to give Discovery launch another try
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A crew of seven astronauts will be on board the Discovery shuttle Sunday evening for a new launch attempt, NASA has announced. The US space agency said it was unable to identify the origin of the leak that foiled the last attempt.
AFP - The US space agency will break with protocol and try to launch the space shuttle Discovery on Sunday even though it has yet to uncover the cause of a hydrogen leak that delayed its mission earlier in the week, officials said.
On Saturday, NASA scheduled Discovery and its crew of seven, including a Japanese astronaut, for a blast-off from the Kennedy Space Center in Florida to the International Space Station (ISS) at 7:43 pm (2343 GMT) Sunday, with a 10-minute launch window.
"From a broad safety perspective we are fine.... We feel good about it," shuttle launch director Mike Leinbach told a press conference.
He said that equipment replacement work was about three hours behind schedule but would not delay the launch, and that leak checks would be performed later Saturday.
But he acknowledged that "no, it's not usual" when asked whether it was normal to fly without resolving a problem such as the hydrogen leak.
"We like to know the root cause for problems. I am a little surprised that we did not find something more obvious because it was a healthy leak," he said, referring to the leak NASA discovered Wednesday in the filling system for the shuttle's external fuel tank just hours before liftoff.
Mike Moses, the head of the mission management team, noted that the leak occurred on the "ground side system," not on the shuttle or the external fuel tank itself.
"I think we're in really good shape," Moses said. "It's really just a (scheduling) risk and we are comfortable proceeding on to launch to tank tomorrow, with the potential risk if we don't find the root cause, it could reoccur and at which point we scrub again."
The leak was found when the external tank was 98 percent full of liquid hydrogen. The tank had to be emptied again for the checks to be carried out, and all components in the filling system were to be replaced and a battery of precautionary checks and tests conducted.
"We did everything we could, which is to replace all the hardware and now we are going to see if it's an alignment issue or not."
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, carrying American businessman Charles Simonyi. 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.
Meteorologists are calling for good weather Sunday for coastal Florida and an 80 percent chance of favorable launch conditions.
A Sunday launch would shorten the 14-day mission to 13 days, and force NASA to scrap one of its four planned spacewalks but the adjustments should not affect the mission to deliver and install a fourth pair of solar panels to the ISS.
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.
Installing the panels on the 100-billion-dollar station was to take a two-astronaut team four space walks of more than six hours each to complete, according to NASA's original plans.
The pairs of solar panels, containing 32,800 solar cells, are each 35 meters (115 feet) long. And the final array, once in place, should boost available energy to the ISS to 120 kilowatts from the current 90.
The extra power will help run the expanded array of scientific experiments to be conducted in the ISS, which saw the addition over the past year of NASA workspace and a pair of international laboratories -- Europe's Columbus and Japan's Kibo.
Discovery's astronauts include Koichi Wakata of the Japan Aerospace Exploration Agency, who is to become the first Japanese crew member on the station.
After Discovery finally docks at the ISS, Wakata is to stay aboard the station, while US astronaut Sandy Magnus -- who arrived at the ISS aboard the shuttle Endeavour in November 2008 -- will return home.