NASA: Space Shuttle on Track for Thursday Launch

In the late afternoon shadows, space shuttle Atlantis is still poised on the pad after its launch on mission STS-122 was postponed on Dec. 6, 2007. CREDIT: NASA/George Shelton.

CAPE CANAVERAL, Fla. ? NASA's space shuttle Atlantis is ready for a Thursday space shot attempt, mission managers said today.

Atlantis is slated to launch the seven-astronaut crew of the STS-122 mission into space from Kennedy Space Center (KSC) on Thursday. Doug Lyons, launch director for the mission, said he's hopeful for an attempt at 2:45 p.m. EST (1945 GMT) ? fickle Florida coast weather permitting, of course.

"We're all thinking that Thursday's the day, regardless of what the weather guy might tell you," Lyons said. "We're ready to make [the launch] happen."

LeRoy Cain, chair of NASA's mission management team here at KSC, said he's confident problems are now resolved with two fuel gauge-like sensors in the bottom of the shuttle's 15-story external fuel tank as well as a kinked radiator hose in the payload bay of Atlantis. Engineers tracked the sensor glitch to a bad electrical connector and replaced it.

"We're not working any issues," Cain said. "We're hoping it will stay that way, of course, and we have some confidence that it will."

Cases closed

Lyons said technicians will constantly test the fuel gauge sensors, known as engine cutoff (ECO) sensors, during fueling of the external fuel tank early Thursday morning.

"We'll be keeping a close eye on our ECO sensors," Lyons said, noting that launch should commence even if one of the four devices fails during testing.

The sensors are designed to stop the three main engines of Atlantis before its 500,000 gallons (1.9 million liters) of fuel runs dry. Because the cryogenic fuel runs through the orbiter's engine cones and cools them as it is expelled and burned, running out of fuel could cause catastrophic damage to the spacecraft, mission managers have said.

Cain said Atlantis' kinked hose is now tucked back into it's intended place, but engineers are still determining whether or not it could leak after the payload bay doors are opened and again closed ? a maneuver that could again cause it to bend outwards in a stressed position.

"We're a long ways from having a leak develop in this particular hose we have on Atlantis," Cain said. But in the unlikely event of a leak, he explained, the orbiter's computers would shut down the redundant radiator system before Freon could leak out.

Anxious for orbit

Navy captain Stephen Frick will head the 11-day mission, the prime objective of which is to deliver the European Space Agency's (ESA) bus-sized Columbus laboratory to the International Space Station (ISS).

Alan Thirkettle, space station program manager for the ESA, said he's pleased with the work done by NASA to get Atlantis into orbit.

"From an ESA point of view that we're very confident and very comfortable with the design fixes ? since December," Thirkettle said. "It seems very, very solid."

As mission managers wait to see if the weather will shape up for a safe launch on Thursday, Lyons said the astronauts are waiting in good spirits.

"They're very anxious to get to launch day, get in orbit, and start their mission," Lyons said.

NASA will broadcast Atlantis' STS-122 mission live on NASA TV. Click here for SPACE.com's STS-122 mission coverage and NASA TV feed.

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