Shuttle landing plan scrapped

NASA scrubbed space shuttle Discovery’s first landing plan tonight because of rain at Kennedy Space Center and was considering ordering a New Mexico landing - something it has done only once before.

Mission Control told the crew that Kennedy remained an option later tonight or tomorrow, though the weather was not expected to improve.

“The new word for Florida is ’unstable.’ The chance has been struck,” astronaut Ken Ham told the Discovery crew from Houston in cancelling the initial 3:56pm EST (8.56pm Irish Time) landing plan.

Ham told the astronauts to hold off on drinking fluids, one of the last steps they take before landing to help them adjust to gravity.

The next opportunities are at Kennedy, White Sands, New Mexico, and Edwards Air Force Base in California’s Mojave Desert, starting around 5:30pm EST (10.30 Irish Time).

Showers at Kennedy and crosswinds at Edwards, the next-best option, increased the chances that White Sands Space Harbor would be the destination for the first time in 24 years. In the only landing there, by shuttle Columbia in 1982, sand on the runway contaminated the orbiter, and the brakes were damaged. The facility is normally not equipped to service the shuttles, either.

“I have a lot of things to worry about on this flight that I can control, and the weather is something I can’t,” Discovery commander Mark Polansky told reporters from space. “I’m ready to land at any of the three sites.”

Discovery needs to be on the ground by tomorrow or it could run out of the fuel that powers its electrical system. NASA normally has more time for the landing, but the astronauts spent an extra day at the international space station this week to work on a stubborn solar array.

NASA managers hoped the weather would clear at one of the favoured sites, but they shipped a crane to White Sands anyway, along with equipment that purges gases and cools and heats the shuttle on the ground, thruster plugs and 60 workers from the Kennedy Space Center.

“As we get closer, we’ll have much more certainty on what we’re really faced with,” said entry director Norm Knight, who will oversee the landing.

If the second landing plan is scrapped, a third opportunity would come around 7pm EST (12am Irish Time) at Edwards and White Sands. NASA managers were considering a last try at 8:36pm EST (1.36am Irish Time Saturday) at Edwards.

NASA has seven more opportunities to land the shuttle.

Discovery originally had been scheduled to land on Thursday, but the flight was extended to allow a fourth spacewalk to fold up an accordion-like solar array on the space station.

On Thursday afternoon, after another inspection and more analysis of the shuttle’s heat shields, the space agency pronounced Discovery safe to return. Shuttles are routinely inspected in flight now for any debris damage of the sort that doomed Columbia in 2003.

During the 25 years of the shuttle program, there have been 63 landings at Kennedy, 50 at Edwards and just one at White Sands.

Even though the White Sands runway regularly is used for practice landings by astronauts, NASA does not like to use it for the real event. It could take as long as two months to get the shuttle back to Florida from New Mexico, compared to a week from Edwards, threatening NASA’s ability to get Discovery ready to fly again next October.