Future spacesuits could heal themselves
11:35 27 July 2006
NewScientist.com news service
David Shiga
Future spacesuits could have some remarkable new abilities. They could self-repair holes, generate electricity and kill germs, thanks to new "smart" materials. Such suits may be ready for use by 2018, when NASA hopes to return to the Moon.
The company that has made spacesuits for NASA since the Apollo missions in the 1960s – ILC Dover LP, in Delaware, US – has been testing these new smart fabrics. It described them last week at the 36th International Conference on Environmental Systems (ICES) in Norfolk, Virginia, US.
The spacesuit would be self-healing because its innermost layer, which provides the spacesuit's airtight seal, is filled with a thick polymer gel. The rubber-like gel is sandwiched between two thin layers of polyurethane so that if a hole forms in these layers, the gel oozes from surrounding areas to plug it. In vacuum chamber tests, the gel healed punctures up to 2 millimetres wide.
If the suit was pierced with a larger hole, the material would immediately alert the astronaut of the hole's location. That is because the material contains a layer that is crisscrossed with current-carrying wires. Large punctures would break circuits in the damaged area, allowing built-in sensors to alert a central computer, says David Cadogan, who manages InFlex, the smart materials programme at ILC Dover.
Radiation blocker
The suit would even be able to provide its own power for those sensors using flexible solar cells that would be sewn into the outermost layer. A variety of these cells is now commercially available, and the company is testing which of the polymer or silicon-based cells would work best on a smart material in space.
The material also keeps microbes at bay using layers of silver-coated polyester. It slowly releases silver ions, which kill bacteria. And layers of polyethylene would also protect astronauts because polyethylene contains a lot of hydrogen, which is a good radiation blocker.
The company has tested these features on various materials but has yet to settle on a final design. It hopes NASA will use the materials in new spacesuits when it sends astronauts back to the Moon.
Cadogan's research group is also designing a sample inflatable habitat using smart materials that could be used as a Moon base or space station. NASA gave up on previous plans for an inflatable module for the International Space Station but it may revive inflatable structures for its return to the Moon. "They have numerous studies going on where inflatable habitats are under consideration," Cadogan told New Scientist.
