Cold Weather Forces NASA to Delay Next Shuttle Launch

Cold weather in Florida has forced NASA to delay its next space shuttle launch to no earlier than April 5, even as its current shuttle mission is still under way.

An unusually long cold snap has kept engineers at NASA's Kennedy Space Center in Cape Canaveral, Fla., from moving the shuttle Discovery out of its maintenance hangar so it can be attached to the external tank and rocket boosters that will help it launch into orbit, NASA officials said Tuesday.

The announcement came while the space shuttle Endeavour is docked at the International Space Station in the midst of a 14-day construction mission to deliver a new room and seven-window viewport to the orbiting lab.

NASA had hoped to try to launch Discovery on a resupply flight to the space station on March 18. But the cold weather in Florida repeatedly prevented shuttle workers from moving Discovery to the cavernous Vehicle Assembly Building to meet its 15-story external tank and twin solid rocket boosters.

Shuttle workers hoped to make the move last week, but are now aiming for Feb. 22 and hoping for warmer weather. If all goes well, Discovery would roll out to its seaside launch pad a week later.

NASA requires four straight hours of acceptable temperatures before a shuttle can be moved from its hangar to the assembly building, NASA spokesperson Allard Beutel at the spaceport told SPACE.com. The temperatures around the time Discovery was to move have been fluctuating between 30 and 40 degrees Fahrenheit.

?We?re unpowered,? Beutel said of a space shuttle during its rollover. ?We don?t have any heaters on there.?

If it is too cold, seals on the shuttle?s reaction control thrusters can leak, NASA officials have said. Other seals can become brittle if they get too cold, Beutel added.

The cold weather was not the only reason for delaying Discovery?s flight until April. In late March and early April, a Russian Soyuz spacecraft is scheduled to return from the station while another is due to blast off with three new crewmembers aboard.

By pushing Discovery?s flight to April 5, NASA will avoid a space traffic jam in which the shuttle?s seven-astronaut crew will be visiting the space station in the middle of crew change operations.

Discovery?s STS-131 mission is a 13-day spaceflight to deliver new science gear and supplies to the space station. The mission is commanded by veteran spaceflyer Alan Poindexter and will include three spacewalks to upgrade the station?s exterior.

The spaceflight is second of NASA?s five final shuttle missions (including Endeavour?s current one) planned for this year before the three-orbiter fleet is retired in the fall.

Endeavour launched to the space station on Feb. 8 to deliver the outpost?s new Tranquility room and an observation deck that has seven clustered windows, providing spectacular views of Earth from space. The European-built additions are NASA?s final major additions for the space station. Together, they cost nearly $409 million.

NASA officials said that it is still too early to tell whether the delay for Discovery will ripple down through the three other missions planned for later this year.

The shuttle Atlantis is slated to launch on its final flight to the space station on May 14. Endeavour and Discovery are scheduled to make the two remaining flights in July and September, respectively.

Currently, the launch dates targeted for those missions are unchanged, NASA officials said.

Endeavour?s six-astronaut crew is due to depart the space station late Friday and return to Earth Sunday night.

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SPACE.com is providing complete coverage of Endeavour's STS-130 mission to the International Space Station with Managing Editor Tariq Malik and Staff Writer Clara Moskowitz based in New York. Click here for shuttle mission updates and a link to NASA TV.