HOUSTON - A new set of solar panels gleamed in the sunlight Tuesday on the international space station as the freshly installed array started opening up.
The first pair of solar wings was fully deployed by early afternoon. The other solar panel would be unfurled later in the day.
It's a slow process. Each wing is unfolded halfway, then allowed to warm in the sun for about 30 minutes to prevented the solar panels from sticking together.
The installation of the new array -- part of the station's third pair of solar panels -- started on Monday, when two astronauts hooked up the new panels, which have a total wingspan of more than 240 feet, during a spacewalk. Engineers at Mission Control then began remotely unfolding the array from its storage box during the night.
On Wednesday, an older solar array will be folded up so it can be moved during a later shuttle mission. The retraction of that array will allow the newly installed pair of panels to rotate, following the direction of the sun.
Atlantis arrived at the space station on Sunday and will be spending an extra couple of days in orbit to allow its astronauts time to fix a thermal blanket near the shuttle's tail that peeled back during launch.
Experts don't believe the gap would pose any threat to the astronauts, though it could allow damage to the shuttle during its re-entry into Earth's atmosphere.
Engineers at Johnson Space Center in Houston were already were practicing techniques the astronauts might use to repair the thermal blanket.
"It was a 100 percent consensus that the unknowns of the engineering analysis and the potential damage ... under the blanket was unacceptable and we should go in and fix it if we could," said John Shannon, chairman of the mission management team.
The thermal blankets are used to protect the shuttle from searing heat during re-entry into Earth's atmosphere. Engineers didn't think the intense heat generated by re-entry could burn through the graphite structure underneath it and jeopardize the spacecraft, but they worried it might cause some damage that would require repairs on the ground.
With three additional shuttle flights to the space station planned this year, NASA can't afford delays.
The repair to the thermal blanket, covering a 4-by-6-inch area over an engine pod, likely will involve an astronaut attached to the end of the shuttle's robotic arm and boom reaching the shuttle's tail area. No decision has been made on whether it will be made during a previously planned third spacewalk or if a fourth, extra spacewalk will be added.
The rest of the shuttle appeared to be in fine shape, Shannon said.
