International Space Station flight engineer Thomas Reiter performed exercises to try to correct a stubborn solar array, NASA officials in Houston said.

National Aeronautics and Space Administration officials said Friday they hope the exercises will fix the problem so another spacewalk wouldn't be necessary.

The array has been in a mid-retracted position since Wednesday, when initial efforts by space shuttle Discovery and ISS personnel to pack it remotely were stopped by incorrect folds, Space.com said. NASA said friction between the array's guide wires as they pass through grommets may be the cause. Astronauts already tried wiggling the array to complete the retraction.

If a spacewalk is required, flight controllers said a simple tug on the guide wire might do the trick.

"I think we'll clear this with (intravehicular) steps," said Mike Suffredini, deputy ISS program manager for NASA. "No matter what we do, the array will always be structurally sound."