Shuttle launch faces weather woes

[Guest Glenn]

Source: news.com.au

 

NASA's crucial decisions ahead of shuttle Discovery's planned liftoff on Saturday (Sunday morning AEST) will begin at dawn, when managers must decide whether to fill the ship's fuel tank for launch, space agency officials said overnight.

 

The shuttle, which has not flown in a year, is scheduled to lift off at 3:49pm EDT (0549 AEST) from the Kennedy Space Centre in Florida on just the second mission since the 2003 Columbia disaster.

 

The biggest immediate concern to NASA is the weather. A 20 per cent chance of lightning near the launch pad could derail plans to begin pumping 500,000 gallons of cryogenic liquid oxygen and liquid hydrogen into the shuttle's fuel tank shortly before 6am EDT (2000 AEST).

 

NASA could delay fuelling for about 90 minutes and still launch Discovery on time.

 

"If we believe we have a reasonable opportunity, we certainly are going to go ahead and tank," said NASA shuttle test director Jeff Spaulding.

 

The weather outlook for launch itself is dicey.

 

Meteorologists predicted a 60 per cent chance of a delay due to the prospect of electrically charged clouds drifting high over the launch site. A shuttle flying through the clouds could trigger a lightning strike, said shuttle weather officer Kathy Winters.

 

The purpose of the mission is to test a second redesign of the shuttle's fuel tank and deliver a new crew member and equipment to the International Space Station.

 

A significant problem with the mission likely would end the shuttle program and seriously affect the half-built orbital outpost. NASA needs to get the shuttles, which are the only vehicles that can assemble the station, back to regular flight service before the fleet is retired in 2010.

 

NASA believes its major issues with the shuttle fuel tank, which triggered the loss of Columbia, are resolved, though some engineers and the agency's top safety officer are not so sure. They unsuccessfully argued for a delay in the launch for additional upgrades.

 

Discovery's mission follows a flight last year that revealed more problems with NASA's initial fuel tank redesign. Managers are hoping to fly three missions this year.

 

Discovery's mission follows a flight last year that revealed more problems with NASA's initial fuel tank redesign. Managers are hoping to fly three missions this year.

 

NASA has until July 19 to get Discovery airborne before having to delay until the next launch opportunity in August. The shuttle is scheduled to spend 12 days in space, though managers plan to add a 13th day for an additional spacewalk to test materials to repair a shuttle's heat shield in orbit.