Tile Repair Kits for Astronauts Rejected

WASHINGTON -- Tile repair kits for astronauts were proposed, developed and even tested dating back to the very beginning of the space shuttle program, but NASA officials repeatedly rejected equipping shuttle crews with supplies for fixing a ship’s protective shield in orbit.

Scientific panels in recent years also urged inspection systems so astronauts could survey the tiles for signs of damage after launch.

Howard Goldstein, a former chief scientist at NASA’s Ames Research Center in Mountain View, Calif., complained: “The thermal protection work has tended to get lower priorities than I believe it should.”

NASA developed and tested an in-flight repair kit in 1980, before the first shuttle launch, but abruptly abandoned the project. It never seriously reconsidered the idea, according to space program advisors.

Tile damage is suspected in the reentry breakup of the shuttle Columbia on Saturday, but there was no advance warning that a hazard might exist. It is too early to know if a tile repair kit could have made a difference. However, the shuttle crew also was unable to make a thorough inspection during orbit.

Since the disaster, NASA officials have said they did not attempt to inspect the shuttle for tile damage, because they did not consider it likely that flight safety had been compromised. Furthermore, there was no repair option available.

But some space experts say the space program should give astronauts that option -- an ability to improvise much as the astronauts did to survive on the nearly catastrophic Apollo 13 mission.

“If the astronauts knew there was a problem, they certainly would have tried to improvise a solution,” Louis Friedman, executive director of the Planetary Society, said. “I do not think they would have dismissed it.”

In 1997, the National Research Council recommended that in-flight repairs were crucial “because many of the orbiter’s potential failure modes caused by meteoroid or debris impact may not be critical immediately but could became critical during reentry.”

For instance, the report said, debris could strike the shuttle’s wings, creating damage that could erupt in “a blowtorch effect inside the wings that causes loss of flight control.”

In fact, some NASA investigators consider space debris or meteorite strikes as the most likely explanations for events leading to the Columbia breakup.

The 1997 report predicted that such strikes could go unnoticed. “If they could be detected and repaired in orbit, the risk of critical failure could be significantly reduced,” the panel said.

Former space shuttle manager Tommy Holloway, responding in 1998, said that analyses of the “orbiter underside have verified the robustness of the tile and structural design to sustain debris impact.”

It is a refrain NASA has repeated for decades.

Several years earlier, scientists at the Ames Research Center proposed equipping shuttles with material an astronaut could inject into a damaged tile with something like a caulking gun. But space shuttle managers did not follow through with the program.

“It was a one-shot deal that would give you something that protected the vehicle for one flight,” said Daniel Leiser, another Ames scientist who worked on detection and repair problems. He considered it an insurance policy for shuttle crews -- “like covering all the bases.”

James Arnold, who retired as the space technology division chief at Ames in October after 40 years with NASA, cautioned against concluding that the on-board repair plan developed at Ames would have been “a magical solution.” He said that without further testing by NASA, it would be impossible to know whether it would have worked. Still, he lamented the fact that it wasn’t even explored.

“I do think we should have put more focus on” tile problems, he said.

The earliest efforts to develop a repair system started in 1979, when NASA developed a complete tile repair system and maneuvering vehicle that allowed astronauts to propel themselves around the orbiter. It involved a type of caulk gun or spray bottle to repair damaged tiles. NASA also planned to equip the shuttle with 162 spare tiles of various sizes. The agency even had an astronaut test the system under weightless conditions.

Former astronaut Charles Bolden, a member of the team that evaluated the kit, said Wednesday every type of material NASA tested failed when placed in a vacuum in ground tests. Nonetheless, Bolden said NASA should develop an inspection process and provide some kind of repair materials that would allow astronauts to improvise in an emergency.

Aerospace industry officials said the repair kit was never given a chance.

A spokesman for Lockheed Martin Corp., whose predecessor company Martin Marietta developed the repair equipment, said they began developing the kit as well as the manned maneuvering unit in September 1979 with the goal of installing the system on the nation’s first shuttle flight.

At the time, NASA officials raised concerns about safely attaching the astronauts to the underbelly of the spacecraft to do the repairs.

There were technical problems as well, limiting the effectiveness of the epoxy developed to fasten the repair tiles. And concern mounted that astronauts on repair missions in awkward conditions could inflict even more damage to adjacent and otherwise sound tiles.

The end, however, came when astronauts John Young and Bob Crippen urged NASA not to test the system on the maiden flight, arguing that there would be too little time to train and carry out the tests along with other more critical missions.

Moreover, NASA officials told the company they were gaining greater confidence in the robustness of the tiles and did not need the repair kit, a Lockheed official said.

But some astronauts continued to be concerned. Former shuttle astronaut Rick Hauck, who chaired the committee that wrote the 1997 report, said it slightly troubled him during his three spaceflights that there was no way to fix a potential problem with the tiles.

In 1983, on his first shuttle mission, he noticed a pit in the window of the crew cabin.

“This was one of the first indications that orbital debris might pose a hazard to the space shuttle,” he wrote in a preface to the report.

The earlier decisions against providing a tile repair kit left NASA officials with few options during the Columbia mission, even though they were concerned that a piece of foam debris had damaged the shuttle during liftoff.

“We have no capacity to go over the side of the vehicle and go underneath the vehicle and look for an area of distress and repair a tile,” Ron Dittemore, NASA’s shuttle program manager, said after questions were raised about what the astronauts could have done if the tiles had been damaged.

“If, for some reason, we thought we had a tile problem, the risk you take when you launch is that you may suffer a tile issue,” Dittemore said. “We have no capacity to repair it. All we can do is, before we launch, design robustness into the system so that a loss of some tile capability will not result in loss of crew or vehicle.”

That approach has left a wake of second-guessing.

Goldstein, who retired as the chief scientist at Ames in 2000, said thermal protection improvements have not been a priority for NASA.

“This catastrophe has all of us just feeling terrible,” he said. “All through the space program, we’ve had the situation where the program managers say we’ve got something that works, don’t change it.”

Times researcher Nona Yates contributed to this report.