March 28, 2012
Engineers Working Towards Laser Deflection Of Asteroids
Protecting the Earth from an extinction-threatening asteroid has in the past been left up to Hollywood, which has deployed a barrage of special effects box office blockbusters that have kept deadly space rocks from smashing our planet into oblivion. But now, Scottish engineers have come up with a plausible way of dealing with asteroids that doesn´t include Hollywood special effects.
Engineers at the University of Strathclyde in Glasgow are developing an innovative technique based on lasers that could literally change asteroid deflection technology as we know it. The scientists envision a swarm of formation-flying satellite drones equipped with powerful lasers that would work together to blow asteroids out of this world.
Until now, researchers have mainly focused on huge satellites carrying massive weapons that could potentially save planet Earth from an asteroid impact.
But the Strathclyde researchers believe the answer lies in smaller ℠fighter´ satellites working together to destroy a huge predator from space.
The researchers, led by Dr. Massimiliano Vasile, of Strathclyde´s Department of Mechanical and Aerospace Engineering, hope to prove that their technology is both safe and effective. They said the use of high power lasers in space for civil and commercial applications were limited and there are challenges in trying to achieve the high power, high efficiency and high beam quality all at the same time.
“The additional problem with asteroid deflection is that when the laser begins to break down the surface of the object, the plume of gas and debris impinges the spacecraft and contaminates the laser,” added Massimiliano. “However, our laboratory tests have proven that the level of contamination is less than expected and the laser could continue to function for longer than anticipated.”
Asteroid impacts aren´t a new threat to Earth. Impacts have occurred rather frequently in the planet´s past, and occasionally, large life-threatening asteroids have caused worldwide devastation, such as the asteroid that wiped out the dinosaurs 65 million years ago.
A closer event than that occurred just over a century ago. Although nowhere near as devastating or life-threatening, the Tunguska meteorite explosion/impact in Siberia that devastated a 1,250-mile area showed just how much damage can be caused. The Tunguska meteorite was believed to be around 100 to 150 feet in diameter.
“The Tunguska class of events are expected to occur within a period of a few centuries. Smaller asteroids collide with Earth more frequently and generally burn in the atmosphere although some of them reach the ground or explode at low altitude potentially causing damage to buildings and people,” said Vasile.
Vasile said their technology is much more feasible than larger satellites carrying massive weapons.
The system is scalable, so that more satellites could be added if a threat is larger. And the system would still continue to carry out its tasks if one happens to fail.
Vasile said the same technique could be used for clearing space debris from orbit, reducing congestion, as the amount of debris littering the planet´s orbit is ever-increasing.
“The amount of debris in orbit is such that we might experience a so called Kessler syndrome — this is when the density becomes so high that collisions between objects could cause an exponentially increasing cascade of other collisions,” added Vasile.
“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. “A major advantage of using our technique is that the laser does not have to be fired from the ground.”
“Obviously there are severe restrictions with that process as it has to travel through the atmosphere, has a constrained range of action and can hit the debris only for short arcs,” said Vasile.
The research was carried out in collaboration with the University of Strathclyde´s Institute of Photonics and was presented to the Planetary Society at the end of February.