Unidentified Debris Keeping Shuttle in Space

NASA delayed today’s scheduled landing of the space shuttle Atlantis for at least a day after onboard cameras spotted what looked like a piece of debris drifting away from the spacecraft.

“We saw something,” said shuttle program manager N. Wayne Hale Jr. at a news briefing Tuesday. “The question is, what is it?”

Atlantis’ crew will perform a five-hour inspection of the outside of the craft today, using the shuttle’s remote arm, which is equipped with a television camera.

If the inspection turns up no damage, Hale said, the shuttle probably will be cleared to land Thursday.

But if a problem is found, or the lighting is poor, the crew will deploy a more sensitive device, the boom sensor, which has a laser that can scan for tiny imperfections. That extra inspection could force another delay, requiring the shuttle to land Friday.

Cameras captured the image of the small, black object moving slowly away from the spacecraft early Tuesday. The camera followed the object for several seconds, but Hale said NASA engineers could not immediately determine its size or mass, or even whether it came from the shuttle.

Another piece of debris was spotted by the crew, but NASA said it appeared to be a plastic bag and of no concern.

Hale said he asked the Air Force for help in tracking the black object, but its proximity to the spacecraft could make it difficult for ground-based radar tracking stations to identify it.

Early speculation among NASA’s top scientists is that something may have shaken loose from the craft’s open 60-foot-long cargo bay when the crew checked the flight controls by firing up the engines, a procedure that sends a powerful shudder through the craft.

It could be something benign, such as a bit of ice or a plastic spacer between the heat tiles, one of which was seen earlier in the mission sticking out from Atlantis’ underside. “Or it could be something more critical that we should pay attention to,” Hale said at the briefing at Johnson Space Center in Houston.

Debris became a major concern for NASA after the 2003 Columbia accident, when the spacecraft and its seven crew members were lost during reentry. A piece of insulating foam from the shuttle’s external fuel tank had damaged the craft during launch.

NASA had already been considering waving off today’s landing because of bad weather. High winds have hit the central Florida landing site, and a thunderstorm swept through Tuesday evening.

After spending most of the day trying to figure out why electronic monitoring devices in one of the spacecraft’s wings had gone off, NASA determined it was caused by shuddering from the engine test. The devices, known as accelerometers, record impacts to the panels covering the leading edges of the wings that are made of heat-resistant, but delicate, reinforced carbon.

Atlantis has been inspected several times in orbit, including when it was docked at the International Space Station. It passed every test. “We found nothing,” Hale said.

NASA is hoping the debris mystery won’t overshadow what Hale called a “spectacularly successful” mission.

Atlantis has enough supplies to stay in orbit until at least Saturday. It also carries four repair kits: two for damage to the leading edges of the wings, and two for repair to the tiles that cover the underside of the shuttle. An additional kit is thought to be back at the space station.

Though the repair techniques have been demonstrated on previous shuttle flights, they have never been used to patch a damaged spacecraft. Astronauts have said that they would prefer to wait for rescue at the space station rather than trust their lives to unproven repairs.

Returning to the space station raises other concerns. A Russian Soyuz spacecraft, carrying a replacement crew and the first female space tourist, was scheduled to dock Tuesday night at the station.

That raises the prospect of a traffic jam if Atlantis has to return, with 12 astronauts sharing the same cramped spaces.

Hale said it was too soon to speculate about a return to the space station. “I feel very comfortable that we will resolve this and protect the crew,” he said.

john.johnson@latimes.com