U.S. Department of Energy - Energy Efficiency and Renewable Energy
NASA Faces a Torn Solar Array and Worn Joint on the Space Station
October 31, 2007
Astronauts in the International Space Station (ISS) discovered a tear
in one of its solar power arrays while deploying it on Tuesday, October 30th.
Spacewalkers from the Space Shuttle Discovery latched and bolted the
space station's oldest solar power module into its new permanent
location on October 30th, allowing the ISS crew to begin unfurling its solar
arrays. Called the P6 module, it was originally installed in a
vertical orientation in the center of the space station, providing a
temporary source of power. When additional solar arrays were added
over the past two years, the P6 solar arrays had to be retracted to
allow the new modules to rotate freely. Now in its final location on
the end of the port side of the station, the solar arrays could once
more be deployed.
One "wing," consisting of two solar arrays, deployed easily, but a
tear developed in one of the solar arrays when deploying the second
wing, bringing that deployment to a halt. As of October 30th, the
National Aeronautics and Space Administration (NASA) was still
assessing how to proceed with the array. Once the P6 array is fully
unfurled, the space station will have six of its eight solar wings
deployed, each of which can produce nearly 33 kilowatts of solar
power. The final module is scheduled to be delivered sometime after
September 2008. See pages 33 to 41 (PDF pages 37 to 45) of the press
kit (PDF 9 MB) for the current shuttle mission, STS-120, as well as the
future launch schedule and a NASA
of the ISS assembly sequence.
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The solar power systems are also creating other headaches for NASA
during this space shuttle mission. Early on the morning of Sunday, October 28th, a
spacewalker discovered metal shavings in a rotating joint that allows
the starboard solar arrays to stay aligned with the sun. Concerned
that the joint may be damaged, NASA disabled it and revised and
extended a spacewalk scheduled for Thursday, November 1st. The spacewalk will now be
used to further examine the rotary joint and will add a day to the
shuttle mission. On October 30th, while moving the P6 module, shuttle
astronauts examined the port solar rotating joint and were relieved to
find no damage. See NASA's Space Shuttle Web page
and the Web page for the current mission.