Cosmonauts on the International Space Station are still troubleshooting a problem with Russian computers that provide backup altitude control and adjustment for the station's orientation.
According to NASA, commands were sent early Friday morning to start the computers, but only one part of the central computer booted up. The plan is now to leave the computers turned off to allow time for Russian Mission Control Center teams to compare notes and develop a new strategy.
Dr. Moira A. Gunn, a former NASA scientist and engineer, said the computer woes could stem from any number of problems. But she said her experience tells her it's a power issue. More specifically, she said she suspects a power spike might have burned out a component that makes the computer boot.
"If lightning hits your house and something is wrong with your computer system, then you know it won't boot up but you are not sure what you fried," said Gunn, who is program director for the Information Systems Program in the College of Professional Studies at the University of San Francisco, and author of "Welcome to Biotech Nation." "This case doesn't seem like a malfunction," she continued. "It sounds to me like they fried something."
Troublesome Solar Panels?
The space shuttle Atlantis and its seven-member crew lifted off from NASA's Kennedy Space Center on June 8 to continue construction of the International Space Station. During the 11-day mission, the crew expected to add a new structural component to the station, deploy a new set of solar arrays, and retract an existing array.
Those solar panels could be part of the problem, Gunn said. "There is a connection between the American side and the Russian side [of the space station], and it could be when they turned on the solar panels, it created the power spike," she explained.
If the computer only needed a new power supply, the solution would be simple, Gunn said, because there are plenty of power sources available. But if something in the computer system is burned out, the issue becomes more complex.
"When you start frying components or power supplies, it may be difficult to get the right parts quickly. That's going to take a while to fix. The good news is they could use one of Russia's unmanned vessels to get the components to the space station," she concluded.
More Repairs Needed
Despite the unexpected computer problems, the astronauts went on their third spacewalk of the week on Friday, a 6.5-hour excursion to repair a thermal blanket on the orbiter and assist in folding up a solar array on the station.
Armed with tools specially designed for the task, two of the U.S. astronauts will keep the solar panels folding properly as their crewmates command the mast to retract. If they're able to get the array completely retracted, they have a list of other jobs to do before ending the spacewalk, NASA said.
"The problem with the computer is not software and it's not a virus," said Gunn. "We are talking about basic systems not booting. If the Russians can get them back up but the problem was created by those solar panels, then you could create another power spike and you'd have problems again. This could be fixed in a couple of days or it could be months."