Date:18 February 2013
I love it when scientists come up with concepts so bold that their colleagues roll their eyes, especially when they talk about way-out stuff like solar-powered asteroid-zappers and near-light speed space travel. (It goes without saying that solid academic credentials make their ideas even more compelling.)
A case in point: physicist Philip Lubin of the University of California at Santa Barbara and Gary Hughes, a researcher from California Polytechnic State University at San Luis Obispo, have conceived something called DE-STAR (Directed Energy Solar Targeting of Asteroids and exploration) as a realistic means of mitigating potential threats posed to the Earth by asteroids and comets.
Last week’s asteroid fly-by, plus the unfortunate Russian experience, has intensified the debate on near-earth objects (NEOs) from Mildly interesting to Bugger, we’re all doomed! Or perhaps not. The Californian scientists’ proposal calls for a system that could (theoretically, anyway) eliminate a 2012 DA14-sized threat in as little as an hour. The same system, they claim, could destroy asteroids 10 times larger in about a year, with evaporation starting as far away as the Sun.
Says Lubin, who began work on DE-STAR a year ago: “We need to be proactive rather than reactive in dealing with threats. Duck-and-cover is not an option. We can actually do something about it…”
Described as a “directed energy orbital defence system”, DE-STAR is designed to harness some of the power of the Sun and convert it into a massive phased array of laser beams that can destroy or evaporate asteroids posing a potential threat to Earth. According to UC Santa Barbara, it will be equally capable of changing an asteroid’s orbit – that is, deflecting it away from Earth or into the Sun – and may also prove to be a valuable tool for assessing an asteroid’s composition, enabling lucrative rare-element mining. The good news: the concept is based on current technology.
Comments Hughes: “This system is not some far-out idea from Star Trek. All the components of this system pretty much exist today. Maybe not quite at the scale that we’d need – scaling up would be the challenge – but the basic elements are all there and ready to go. We just need to put them into a larger system to be effective, and once the system is there, it can do so many things.”
In developing their proposal, Lubin and Hughes calculated the requirements and possibilities for DE-STAR systems of several sizes, ranging from a desktop device to one measuring 10 km in diameter. Larger systems were also considered. As they tell it, the larger the system, the greater its capabilities.
For instance, DE-STAR 2 – at 100 m in diameter, or about the size of the International Space Station – “could start nudging comets or asteroids out of their orbits”, say the scientists. But DE-STAR 4 – at 10 km in diameter – could deliver 1,4 megatons of energy per day to its target, obliterating an asteroid 500 m across within a year.
But wait… there’s more. According to Lubin, the even bigger DE-STAR 6 system could enable interstellar travel by functioning as a massive, orbiting power source and propulsion system for spacecraft. It would be capable of propelling a 10-ton spacecraft at near the speed of light, allowing interstellar exploration to become a reality without waiting for science fiction technology such as “warp drive” to come along.
Hughes makes the point that we need to take stray asteroid and comets seriously. “There are large asteroids and comets that cross the Earth’s orbit, and some very dangerous ones are going to hit the Earth eventually. Many have hit in the past and many will hit in the future. Realistic solutions need to be considered, and this is definitely one of those.”
* Source: UC Santa Barbara