Spaceflight Now: Breaking News

Engineers tackle real-life 'Mission' to fix spacecraft
Posted: March 23, 2000

  Repair kit
NASA's Steve Hall demonstrates a space station patching operation. Designed by Hall and a team of Marshall Space Flight Center engineers, the patch is designed for external repairs to the spacecraft's hull in the rare event it is punctured by meteoroids or space debris. After the circular patch is securely bolted over the damaged area, a strong epoxy adhesive is pumped into the disk via an injector device much like a caulking gun. This epoxy is allowed to harden, completely sealing the puncture until permanent repairs can be made. Photo: NASA/Marshall
When a spacecraft in the new movie "Mission to Mars" is caught in a fierce meteoroid storm, the beleaguered crew rallies to patch the damaged hull, and thrilling movie music swells over the hiss of escaping air.

Real astronauts facing actual damage to their spacecraft won't have the luxuries of stuntpeople, special effects or inspiring musical crescendos to save them from the cold vacuum of space. That's why NASA engineer Steve Hall and a team of researchers at NASA's Marshall Space Flight Center in Huntsville, Ala., are hard at work on a real-life hull-puncture repair kit -- one that will protect lives and vehicles as humans venture into space for longer periods of time.

The kit, intended for use on the International Space Station, is designed to seal punctures up to 4 inches in diameter caused by collisions with small meteoroids or space debris. With a few simple tools and a couple of extra-vehicular spacewalks, crewmembers can safely repair punctures from outside damaged modules that have lost atmospheric pressure.

"It pays to be prepared," Hall says. A hole as small as 1 inch in diameter in a vehicle the size of the Space Station could bleed off enough air in just one hour to put the crew at risk. That doesn't give them much time to locate the damage and seal the leak from inside the station -- especially when bulky equipment and experiment racks may block access to many of its interior walls.

Repair kit
The kit includes a clear Lexan disk which may be securely bolted over the damaged area. A strong epoxy adhesive is then pumped into the disk and allowed to harden, completely sealing the puncture. Photo: NASA/Marshall
"Protecting the lives of the crew is the most important thing," Hall says. "The safest approach is for the crew to evacuate and seal off the damaged module, allow it to fully depressurize and then make repairs externally."

The patching operation would begin with a spacewalk to locate damage on the exterior of the depressurized module. The surrounding area would be cleaned and the hole measured with special tools, enabling the crew to select patch components precisely tailored to the size of the damage.

A second spacewalk would then deliver the patch kit to the work site. The patch consists of a clear disk that would be solidly bolted to the module's metal surface, covering the crack or puncture. A strong epoxy adhesive then would be pumped into the hollow disk by an injector that looks like a double-barreled caulking gun. Once this adhesive cures -- a process that takes two to seven days -- it forms a cast plug that would completely seal the hole. Then the module would be gradually repressurized to verify proper function of the seal.

The patch is designed to last for at least six months, Hall says, giving the crew ample time to make permanent repairs as needed.

Development and testing of the patch kit is under way at the Marshall Center. It is slated for delivery to the Space Station in September.

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