A solar power panel ripped as it was being unfurled from a newly reinstalled girder on the International Space Station today, forcing Nasa to halt the operation and throwing expansion plans into doubt.
Part of the lengthy, wing-shaped panel looked torn and crumpled in television shots from space. Nasa had called the array deployment critical to providing electricity for European and Japanese
The damaged right solar array on the International Space Station is visible in this image from Nasa TV
laboratories scheduled for delivery starting in December, after a massive joint that rotates another solar panel malfunctioned.
Astronauts on the station stopped unfurling the panel when they spotted the damage, but said the glinting sun had prevented them from seeing it sooner.
"It looks like the damage appeared fairly suddenly," said Pamela Melroy, commander of the space shuttle Discovery, which is docked at the station.
Nasa engineers at Mission Control in Houston told the astronauts to shoot photos of the damage for study on Earth and had them partially retract the panel to take tension off the tear.
There was no immediate word on what Nasa's next move would be, but officials said yesteray if there were problems with deploying the array, spacewalking astronauts who had planned to take a look at the troubled rotating joint would instead work on the solar panel.
The mishap cast a cloud over what had been a successful day for the astronauts, who earlier installed on the station the 17.5-tonne truss in which the panel was stowed.
With spacewalkers Scott Parazynski and Douglas Wheelock helping guide it, Daniel Tani and Stephanie Wilson had used the station's robot arm to put the 10-metre girder in place at the end of the station. It had been sitting atop the station for seven years.
"Looks good, spaceman," one of the spacewalkers said as they performed the task. Once the girder was attached, half of the solar array, which has two separate panels and is 73 metres long when fully extended, was unfurled without a hitch.
The problem occurred when the other half was being deployed. It added to power woes on the station after Nasa shut down on Sunday one of two three-metre rotating joints on the station that enable solar power arrays to track the sun and generate electricity.