Some disasters make even our present problems -- climate change, ecosystem meltdowns, massive social instability, lurking pandemics -- look like strolls through the park. One of them: the Earth getting smacked by a Big Icy Chunk of Rock from Outer Space. That's a game-over kind of catastrophe, at least potentially.
We've written frequently before about how to avoid a BICROS impact before, about lunar arks, distributed collaborative astronomers scanning the skies for danger, gravity tugboats, even swarming satellites. The common conclusion? We don't yet have an adequate BICROS prevention strategy.
So I was stoked to read Sunday about a new idea for avoiding an interplanetary smack-down:
Massimiliano Vasile, a lecturer in aerospace engineering at the University of Glasgow, recently concluded a two-year study comparing nine asteroid-deflection methods, rating them for efficiency, complexity and launch readiness.
The best method, called “mirror bees,” entails sending a group of small satellites equipped with mirrors 30 to 100 feet wide into space to “swarm” around an asteroid and trail it, Vasile explains. The mirrors would be tilted to reflect sunlight onto the asteroid, vaporizing one spot and releasing a stream of gases that would slowly move it off course. Vasile says this method is especially appealing because it could be scaled easily: 25 to 5,000 satellites could be used, depending on the size of the rock.
The engineer goes on to explain Vasile's thinking:
A single mirror would be effective, but it would need to be up to 10km across, he said; but using technology from missions involving constellations of satellites, multiple spacecraft could be flown in formation, with smaller mirrors, to focus the sunlight onto a single spot, 1-1.5m across. ‘If we have a satellite with a mirror 2m in diameter, we would need 1000 of them, and they’d have to focus the sunlight for 90 days to deflect an asteroid the size of Apophis,’ he said. ‘But if we go up to 20m, we’d need ten satellites and 200 days.’ The satellites would weight about 500kg, which is lighter than the satellites for the Galileo global positioning system, he added. ‘It’s well within our launch capabilities.’
Maybe we need an X Prize for mirror bee deployment systems?