Washington  - The space shuttle Discovery was fueled and ready for blast off early Tuesday - with the blessing of a television comedian who foiled NASA's internet vote to name part of the International Space Station.

Discovery, set to blast-off at 1:36 am (0536 GMT) from Kennedy Space Centre on Florida's Cape Canaveral, is acting as a moving van with a full load of new equipment and experiments, marking a huge advance in the space station's capability as an orbiting laboratory.

Among the station's newest equipment will be a new sleeping compartment and a treadmill named after Stephen Colbert, who plays a pompous news commentator on the Comedy Central channel's Colbert Report.

Earlier this year, he organized fans to vote for him in a NASA competition to name an ISS module. His name came first in the US space agency's online poll, besting all of NASA's suggested names.

With egg on its face, NASA rejected the outcome of the vote, saying that it does not name space hardware after living people. Instead, it chose the name Tranquility, after the 1969 moon landing site, the Sea of Tranquility.

Scrambling to show a sense of humour, NASA named a new treadmill in Colbert's honour, concocting the COLBERT acronym: the Combined Operational Load Bearing External Resistance Treadmill.

While not attending the launch, Colbert delivered a two-minute video message, in character. He gloated about winning the contest, ribbed NASA for its bland module name and celebrated that the treadmill would "slim down all those chubby astronauts," before offering congratulations to the agency.

"We are all huge fans here, and it has been a true honour to make merciless fun of you this year. Now, this is Stephen Colbert saying: I am go to launch me. Let's light this candle."

Astronaut fitness aside, the most important advances during the 13-day shuttle mission will be the delivery of a variety of equipment for use in scientific experiments on the station.

The crew of six US and one Swedish astronaut are bringing two racks for scientific experiments and a freezer to store experiments to be carried back to Earth. One of the racks will be used to conduct research on metals, semi-conductors, crystal, glass and other materials in microgravity. The other will be used to study liquids and gels in space.

The astronauts will conduct three spacewalks during the shuttle flight.

US astronauts John "Danny" Olivas and Nicole Stott will remove a spent 816-kilogramme ammonia tank during the first spacewalk. The ammonia is used to remove heat from the station.

The storage tank is the largest item ever moved by astronauts during a spacewalk. While outside the station, the duo will bring in experiments that have been stored outside to study the effects of direct exposure to open space.

Stott is to replace US astronaut Tim Kopra on the six-member long- term ISS crew.

A new ammonia tank will be installed by Olivas and Swedish astronaut Christer Fuglesang in the second spacewalk. They will team again in the third spacewalk to begin preparations for a further expansion of the ISS with the installation of the Tranquility module next year.

Discovery's mission comes as NASA attempts to complete the orbiting ISS before the ageing US shuttle fleet is retired next year.

Including Tuesday's launch, only seven shuttle missions remain before NASA halts its flights to the ISS by the end of 2010. The agency is developing a new, moon-bound spacecraft called Orion, which could be ready for trial flights by 2015.

Until then, US astronauts will have to rely on Russia's rocket- mounted Soyuz space capsules to travel to and from the ISS. (dpa)