Shuttle Discovery on Track for Thursday Launch

The space shuttle Discovery is settled on its Launch Pad 39B for launch of mission STS-116. Work crews hauled the orbiter and its launch stack to Pad 39B on Nov. 9, 2006 for a Dec. 7 launch. CREDIT: NASA/Amanda Miller.

CAPE CANAVERAL, Fla. - Launch countdown proceedings are going smoothly for the planned Thursday liftoff of NASA's space shuttle Discovery.

"Our systems are currently in great shape," said NASA test director Steven Payne in a status briefing here at the Kennedy Space Center. "Countdown is progressing and we have no issue of consequence."

Thursday's planned space shot is set to commence at 9:35:47 p.m. EST (0235:47 Dec. 8 GMT). It will mark NASA's third shuttle launch this year and the agency's first night launch since 2002. The shuttle's bright engine plume should be visible to skywatchers along the eastern United States, weather permitting. [Click here for a viewing map.]

The weather forecast for launch day dipped slightly this morning in response to a cold front that moved through Central Florida yesterday, but still stands at a 70 percent chance of favorable flight conditions. Weather conditions are expected to degrade significantly to 40 percent if Discovery's launch is delayed until Friday or Saturday.

"Overall, the first day is the best day weather-wise," said NASA shuttle weather officer Kathy Winters. "Our main concern will be the ceiling on launch day and winds the following two days."

The launch window currently runs from Dec. 7 to 17, but extensions are possible if shuttle mission managers approve Discovery for flight over the end-of-year rollover.

"Some of the computers handle the New Year in a [different] way," Payne explained. "Some of them go to Day 366 and some go to Day 1, so it requires a reboot in order to get them all to talk to each other and be synchronized. Our preference is not to have to do that, but it's not a showstopper."

Led by commander Mark Polanksy, the five-man, two-woman crew of STS-116 arrived here at Kennedy Space Center (KSC) Sunday afternoon and countdown clocks for the launch began ticking at 11:00 p.m. Monday night (0400 Dec. 6 GMT). The astronauts are performing a series of spacesuit fittings, medical checks and going over their orbiter and payload systems today, NASA officials said.

The STS-116 crew is tasked with rewiring the electrical grid of the ISS and delivering a new $11 million portside piece of the orbital laboratory. Mission specialists Sunita Williams will also relieve ESA astronaut Thomas Reiter who has been aboard the station since July.

A built-in four-hour hold is scheduled for 3:00 p.m. EST (2000 GMT) today. The countdown will pick up again at 7:00 p.m. EST (0000 Dec. 7 GMT). Among the day's scheduled tasks are some checks of the small explosive devices designed to separate the shuttle from its mobile launch pad, and the loading of cryogenic fuel that powers Discovery's fuel cells.

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