NASA clears shuttle for launch try

CAPE CANAVERAL, Fla., Dec 9 (Reuters) NASA managers cleared space shuttle Discovery for a second launch attempt to night but bad weather and work delays on the launch pad could prompt another postponement.

Managers planned to meet again at 12:30 p.m. EST (2300 hrs IST) to see if workers were able to catch up on tasks that fell behind schedule earlier in the day and delayed the start of fueling the shuttle for liftoff.

Liftoff was set for 8:47:34 p.m. today (0717 hrs tomorrow). But if workers cannot begin filling the fuel tank by early afternoon, the next opportunity for launch would be 8:25:02 p.m. tomorrow (0645 hrs on Monday).

The launch would be NASA's first after sunset since before the 2003 Columbia disaster. Managers recently lifted the ban on night launches, imposed to ensure cameras had good lighting to spot any debris falling off the shuttle's fuel tank.

The weather forecast looked bleak, with a 70 per cent chance of high winds, rain and clouds that would make liftoff unacceptable on Saturday.

NASA hopes to get its third and final shuttle mission of the year airborne before December 17 and avoid a potentially troublesome and time-consuming effort to update Discovery's computers during flight to accommodate the transition to the new year.

The shuttle's computers, not designed to fly through a year-end rollover, would fall out of sync with ground-based systems.

The goal of Discovery's 12-day flight, which would be the 117th in shuttle program history, is to rewire the International Space Station so partner laboratories built by Europe and Japan can be installed next year.

The crew was strapped in and ready for an initial launch attempt on Thursday night but a thick ceiling of clouds failed to part before the Earth rotated out of position for Discovery to reach the space station.

Yesterday's weather was too poor to even attempt a launch.

NASA needs good visibility to track the shuttle at liftoff, and the winds have to be calm enough to permit a landing in case of emergency.

Commander Mark Polansky leads a crew that includes Sweden's first astronaut, Christer Fuglesang, along with pilot William Oefelein, flight engineer Robert Curbeam, and mission specialists Nicholas Patrick, Joan Higginbotham and Sunita Williams.

Four years ago, debris damaged Columbia during its launch and caused it to break apart as it re-entered Earth's atmosphere, killing its seven astronauts. The fuel tank has since been redesigned.

REUTERS PDM RN2250