A material that could enable spacecraft to automatically 鈥渉eal鈥� punctures and leaks is being tested in simulated space conditions on Earth.
The self-healing spacecraft skin is being developed by Ian Bond and Richard Trask from the University of Bristol, UK, as part of a European Space Agency (ESA) project.
The researchers have taken inspiration from human skin, which heals a cut by exposing blood to air, which congeals to forms a protective scab. 鈥淭he analogy is the vascular system of the human body,鈥� Bond told 快猫短视频. 鈥淭he system needs to be completely autonomous.鈥�
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The researchers came up with a similar idea for protecting spacecraft. They fabricated a composite laminate material containing hundreds of hollow glass filaments 60 microns (thousandths of a millimetre) wide, each with an inner chamber of 30 microns in diameter. Half of the filaments are filled with an epoxy polymer or resin and the other half filled with a chemical agent that reacts with the polymer to form a very strong and hard substance.
Space environment
The glass filaments are designed to crack easily when the overall composite material is damaged, which causes both chemicals to leak out and rapidly plug the resulting crack or hole. 鈥淲e鈥檝e demonstrated we can restore strength by doing this,鈥� Bond says, 鈥渁nd that it can stand the space environment.鈥�
The pair then successfully tested the self-repairing material in a vacuum chamber to see whether it would work in a space-like vacuum, and also investigated the effect of gravity on the skin鈥檚 protective properties when covering the top or the underside of a craft. They now plan to develop stronger materials containing the healing filaments and to test them in even more extreme conditions, such as very high temperatures.
Christopher Semprimoschnig, at ESA鈥檚 European Space Technology Research Centre (ESTEC) in the Netherlands, is heading up research into self-healing technology at the space agency.
He hopes that it could protect spacecraft from micrometeroids. These are fragments of space debris just a few millimetres in size that may travel at several thousands of metres per second in orbit 鈥� fast enough to damage a satellite or crewed spacecraft, and cause serious damage.
Sensing air leaks
The technology could also protect craft from leaks caused by the extreme temperatures of space travel. It could also safeguard against damage incurred during take off 鈥� an issue that has become a prominent concern for NASA following the shuttle Columbia disaster. A chunk of foam fell from the Columbia鈥檚 external tank during take-off, and punctured the shuttle鈥檚 left wing, leading to its destruction upon re-entry.
Other researchers are currently working on improved methods to detect potentially hazardous breaches in a spacecraft鈥檚 hull. A team at Iowa State University, US, have developed a vibration sensor capable of pinpointing potentially dangerous from inside a craft.
But the first self-healing space vehicles may not be ready for launch for some time yet. 鈥淲e have taken the first step but there is at least a decade to go before this technology finds its way onto a spacecraft,鈥� says Semprimoschnig.
