Space Station Primed to Unfold New Radiators
This computer generated image shows the International Space Station in its current configuration as of Sept. 29, 2007 after its two oldest solar arrays were furled outside the Russian Zarya control module. The folded arrays can be seen tucked close to Zarya, the module near the left center in this view.
Credit: NASA

The International Space Station (ISS) is primed to unfold new radiators later this month after successfully furling its oldest solar arrays.

Once sporting a wingspan of almost 80-feet (24.4 meters), the two wing-like solar arrays of the space station's Russian Zarya control module folded away after nearly nine years generating power for the orbital laboratory.

The solar arrays had been deployed since November 1998 shortly after Zarya, the first piece of the ISS to fly, launched into space to begin the station's construction. They were retracted last weekend to clear space for future radiators that will unfold during and after NASA's next shuttle flight, STS-120 aboard Discovery, slated to launch on Oct. 23.

"They have to be out of the way for the radiators to deploy," NASA spokesperson James Hartsfield, of the agency's Johnson Space Center in Houston, Texas, told SPACE.com. "Each one took about one minute to two minutes to retract. There were no glitches at all."

Zarya's solar arrays are still generating some power, but not the average three kilowatts they once provided while fully unfurled, NASA said. The electricity from the station's expansive U.S. solar arrays, which reach out from the station's port and starboard sides and each generate about 66 kilowatts of power, is more than sufficient to make up for the drop in Zarya's production, the space agency added.

Another pair of Russian solar arrays continues to produce power from their perch on the station's aft-mounted Zvezda service module.

With the successful retraction of Zarya's solar arrays, the stage is now set for NASA's STS-120 shuttle mission.

Commanded by veteran shuttle flyer Pamela Melroy, Discovery's seven-astronaut crew will deliver a new connecting node to the ISS, relocate an older U.S. solar wing and test orbiter heat shield repair methods during a planned 14-day mission.