Laser swarm could swat asteroids away
It sounds like the climactic scene from a sci-fi thriller: A group of small satellite-operated lasers flying in formation redirects an asteroid headed for catastrophic collision with Earth. But this isn’t the movies; this is a technique that could radically change asteroid-deflection technology.
Researchers at the University of Strathclyde in Glasgow, UK, are exploring the possibility that relatively small satellites collectively could fire solar-powered lasers at close range to a threatening asteroid. The approach could have advantages over current methods, which focus on large, unwieldy spacecraft.
This photo was taken in an experimental laboratory, demonstrates the process of shining a solar-powered laser onto an asteroid.
“We could reduce the threat posed by the potential collision with small- to medium-size objects using a flotilla of small, agile spacecraft, each equipped with a highly efficient laser, which is much more feasible than a single large spacecraft carrying a multimegawatt,” said project leader Massimiliano Vasile, a reader in the university’s mechanical and aerospace engineering department.
“Our system is scalable – a larger asteroid would require adding one or more spacecraft to the flotilla – and intrinsically redundant: If one spacecraft fails, the others can continue,” Vasile added.
Although large asteroids do not often collide with Earth, the situation is not without precedent. More than a century ago, a meteorite believed to be about 120 ft across entered the atmosphere over Siberia and exploded in the sky. The Tunguska event, named after a river in the region, devastated 800 sq miles of remote forest – felling an estimated 80 million trees.
Smaller asteroids, which pose a lesser threat, collide with Earth more frequently but are likely to burn in the atmosphere.
Strathclyde researchers Alison Gibbings and Massimiliano Vasile are developing a novel technique that would use a group of smaller satellite-operated space-borne lasers to redirect asteroids and manage human-created space debris. Images courtesy of University of Strathclyde photographer Graeme Fleming.
One problem with asteroid deflection is that, when the laser begins to break down the surface of the object, the resulting plume of gas and debris impinges the spacecraft and contaminates the laser, Vasile said. But the group’s laboratory tests proved that the contamination level is lower than expected and that the laser could continue to function for longer than anticipated, he added.
A major advantage is that the laser does not have to be fired from the ground: Having to travel through the atmosphere would constrain its range of action.
The laser swarm also could help control the accumulation of space debris – objects created by humans that remain in orbit. The lasers could lower the original orbit of debris and reduce congestion, Vasile noted.
“While there is significant monitoring in place to keep track of these objects, there is no specific system in place to remove them, and our research could be a possible solution,” he said.
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