for National Geographic News
Spacecraft, heal thyself.
Aerospace engineers are developing self-repairing materials that "heal" themselves when damaged.
Shuttles, probes, and satellites sheathed in the stuff could safeguard craft from the wear and tear of space, researchers say.
Cosmic craft are "constantly being barraged by all sorts of nasties," said Ian Bond, an aerospace engineer at the University of Bristol in England.
Hazards include whizzing dust and space junk and extreme temperatures, which can cause structural breaks and cracks.
Those threats and others can weaken spacecraft until they suffer catastrophic structural failures, Bond says.
So why not build shuttles, satellites, even airplanes, from materials that repair minor damage automatically?
To develop a material that mends nicks and scrapes on its own, Bond and his colleagues turned to a counterintuitive solution that uses fragile glass tubes.
The thin, hollow fibers are filled with one of two liquids that quickly solidify into epoxy resin when mixed.
The engineers incorporated rows of these glass tubes into building panels similar to those used to construct spacecraft.
"As long as those fibers break during an impact event," Bond said, "the resin can bleed out into the damage and harden up."