Space shuttle fuelling up for Monday launch

08/02/2010 07:15:41

NASA began fuelling the space shuttle Endeavour for a Monday morning launch amid concerns that low clouds over Florida's Kennedy Space Center could delay lift-off a second time.

Endeavour and its six astronauts are to blast off at 4:14 a.m. (9:14 a.m. British time) on a 13-day trip to install the last two main pieces of the International Space Station.

Blast-off was originally set for early Sunday morning, but low clouds descended over the launch pad, violating safety rules for flight.

Crews began filling the shuttle's giant external fuel tank as night fell on Sunday evening, but there was only a 60 percent chance of acceptable weather for launch, NASA spokesman George Diller said.

Scattered clouds threatened visibility, though "there is some possibility that could improve over the course of the evening," Diller said. "We're cautiously optimistic that the weather will go our way."

With high humidity and a relatively chilly temperature of 48 degree Fahrenheit (9 degrees Celsius), crews also were concerned about the possibility of ice build-up on the tank, which was being filled with super-cold liquid propellants, Diller said.

Monday morning's launch was expected to be the final launch carried out in darkness for NASA's shuttle fleet, which is scheduled to be retired after completing five missions this year.

Endeavour's crew is to install the space station's last connecting hub and a dome-shaped cupola with seven windows to provide the crew with panoramic views outside the station. With those parts installed, the space station will be about 90 percent c omplete.

Four more shuttle missions remain to deliver cargo platforms, spare parts, a Russian docking port and scientific experiments.

(Additional reporting by Irene Klotz)