An asteroid exploded over the Atlantic Ocean without warning last month, unleashing the force of multiple nuclear weapons into the atmosphere. It could have caused extensive damage had it hit in a populated area. If only there were some way to shove these killer asteroids off of their killer path before they blast us to bits. Researchers in California say their asteroid-deflecting laser weapon has been tested on a small scale and is ready for a full-sized model.
Generally speaking, the technology is available today. The main challenge with building a full DE-STAR is the necessary scale to be effective.
That’s Qicheng Zhang of the University of California, Santa Barbara, from a recent report he co-authored in the Publications of the Astronomical Society of the Pacific, talking about DE-STAR or Directed Energy System for Targeting of Asteroids and exploRation, a project to build a large phased-array laser in Earth orbit to deflect asteroids, comets, and other NEOs (Near-Earth Objects) like the direct hit in February or the monster that exploded over Chelyabinsk, Russia, three years ago.
According to the report, DE-STAR’s laser would heat the surface of an asteroid to the point of vaporization, which would create a gaseous force that moves the object into a new, non-collision path. On a large scale, a DE-STAR with a 330-feet-wide phased laser array could divert an asteroid 330 feet in diameter when it was still two million miles away.
A second, smaller system called DE-STARLITE would position a spacecraft close to the NEO and use low power over a longer time to deflect it. The factors to consider when selecting DE-STAR or DE-STARLITE are size and time, says Zhang.
The bigger the NEO, the longer the time needed. The bigger the laser, the shorter the time needed. With a very small 20 kW DE-STARLITE, a 300-meter-wide (1,000 foot) asteroid can be deflected in 15 years. Smaller asteroids can be deflected in under a year, after the spacecraft’s arrival at the asteroid.
The good news is that the system has already been tested on a small scale at the University of California-Berkeley. A laser was directed at a piece of basalt – a rock similar in composition to most asteroids – under outer space conditions and the rock reached vaporization, emitting a plume of gas with enough force to have pushed it out of its path on this small scale. The researchers also spun the rock and then used the laser to change its rotation and speed.
All we need now is funding. That could come from the potential for asteroid mining that the DE-STAR could aid with its de-spinning capability.
A big killer asteroid might speed things up too.