NASA Adds 3rd Spacewalk, Extra Day to Shuttle Mission

After analyzing the shuttle’s energy consumption, NASA officials on Friday decided to extend Discovery’s mission by an extra day and add a third spacewalk to the astronauts’ itinerary.

Astronauts Piers J. Sellers and Michael E. Fossum will use the extra spacewalk Wednesday to practice making repairs to the carbon material that protects the shuttle’s nose cone and the leading edge of the wings from extreme heat, said John Shannon, deputy shuttle program manager.

The pair might also take the opportunity to remove a protruding gap filler -- a small strip of ceramic-coated fabric wedged between the shuttle’s delicate heat-resistant tiles -- that is sticking out slightly more than an inch beyond the craft’s surface.

Discovery, which is docked with the International Space Station, is now scheduled to land at Kennedy Space Center in Florida on July 17 after 13 days in orbit.

“It’s great news, because it gives us a whole lot more capability and a little more bang for the buck,” space station astronaut Jeffrey N. Williams told Associated Press Television News.

“We’ve got a long way to go to finish the assembly of the space station, so every step that we’re able to accomplish is important to doing that.”

The shuttle astronauts spent part of Friday continuing their inspection of Discovery for possible damage.

Using a camera attached to the end of the shuttle’s 50-foot-long robotic arm, the astronauts scanned the shuttle’s surface, focusing on six areas of possible damage.

Three of the areas have already been analyzed by NASA engineers and were found to pose no safety threat to Discovery.

The other three are expected to be cleared over the weekend, Shannon said.

The “systems couldn’t be functioning better,” said Steve Poulos, manager of the orbiter projects office. “Our white board in the mission evaluation room is relatively clean.”

Sellers and Fossum are scheduled to conduct their first spacewalk today.

The six-hour excursion will test the astronauts’ ability to perch themselves on the end of the shuttle’s robotic arm to make repairs to hard-to-reach areas of the craft’s heat shield.

The pair will simulate various repair-related movements with the arm in at least three different positions.

The shuttle crew spent Friday transferring a supply module from Discovery’s cargo bay to the space station and beginning the weeklong process of unloading more than 7,000 pounds of food, clothing and equipment.

Among the provisions are a freezer to store samples from scientific experiments, an incubator for growing plants in space and a second oxygen generator that will allow the space station to accommodate a crew of six.

Times wire services were used in compiling this report.