This is an excerpt from EERE Network News, a weekly electronic newsletter.

June 13, 2007

Shuttle Visit Adds More Solar Power to the Space Station

The International Space Station (ISS) received an additional boost in its solar power capacity on June 12th, as the latest space shuttle mission, STS-117, added another set of solar panels. Following its launch on Friday, June 8th, STS-117 rendezvoused with the ISS on Sunday, June 10th. On Monday, June 11th, a truss carrying the new solar panels was removed from the shuttle bay and installed on the starboard side of the ISS. The shuttle crew then made the electrical connections for the new solar panels that afternoon and unfurled the two sets of solar panels on Tuesday, June 12th.

Photo of an astronaut in a space suit suspended over a solar panel that is bunched up like an accordion. The astronaut is using an improvised tool to free a stuck solar panel. Part of the Earth is visible in the background.

Astronaut Robert L. Curbeam Jr. works to free a stuck solar panel during shuttle mission STS-116 in December 2006.
Credit: NASA

Starting on June 13th, the crew has the unenviable task of retracting a solar array that was installed on the ISS in 2000. Last year, STS-116 had considerable difficulty retracting the port "P6" solar array to allow the new port solar panels to rotate freely. This year, STS-117 is retracting the starboard "P6" solar array to allow the new starboard array to rotate. The STS-117 crew has a number of tools developed by the previous mission to help them with their task, but just in case, the National Aeronautics and Space Administration (NASA) has allowed up to three days to fold up the solar array into its storage box. See the NASA Shuttle Web page, the STS-117 mission description, the "ISS Assembly Sequence" animated video, and this newsletter's coverage of last year's STS-115 and STS-116 missions.

The new starboard solar panels add another 66 kilowatts of power, increasing the power available to the ISS by about 50 percent. STS-120, scheduled for October, will move the P6 to the port end of the ISS and redeploy the solar arrays, adding another 66 kilowatts of power, and STS-119, which currently lacks a launch date, will carry the fourth and final set of solar arrays to the ISS. See the "Future Assembly Sequence," the "Integrated Truss Structure," and the "Integrated Truss Structure Interactive" on the NASA Web site.