Asteroids Threaten Earth? New Study Details Laser Ablation Method
A new study by American astronomers and physicists details a method for using a large phased-array laser to protect our planet from asteroids or comets.
Directed energy is a promising technology for planetary
defense. A modest stand-on DE-STARLITE mission of
just 1 MW (100 N), which fits within a single SLS Block 1
launch configuration, can deflect all known threats up to
500 m in diameter with 5 yr of laser activity. That same
system could deflect Tunguska- or Chelyabinsk-sized asteroids
in well under a year upon arrival at the asteroid.
With the strong dependence of deflection on laser active
time, a much smaller and less expensive system could be
equally effective given a decade or more of activity. Conversely,
stand-on systems are largely ineffective at de-
flecting targets on short notice due to the time required
for transit to the target asteroid.
In the absence of more than a few weeks of warning, a
very large stand-off DE-STAR system becomes the only
option. In addition to providing a last line of defense
against threats which have evaded detection until immediately
before impact, such a system may also provide
one of the few options for defense against long period
comets to which modern technology is often incapable of
reaching by spacecraft. With the support of a battery
system, the ablation range and thus effectiveness for a
stand-off system might conceivably be extended by a few
factors. Even so, a system of sufficient scale will likely
require decades to construct and so becomes a possibility
only in the more distant future.
It seems to me that the writers of Star Trek TOS in the sixties envisioned something similar. Fans of Star Trek of course remember the classic episode The Paradise Syndrome, in which a mysterious obelisk protects a planet from destruction with an energy beam of incredible power.
(The Paradise Syndrome)
SPOCK: This obelisk is one huge deflector mechanism. It is imperative that we get inside immediately. Captain, we do not have much time.
KIRK: I don't know how to get inside.
SPOCK: If we are not able to gain entry and activate the deflector mechanism within the next fifty minutes, this entire planet will be destroyed.
KIRK: The key must be in these symbols. We've got to decipher them.
SPOCK: I already have to some extent, Captain. They are musical notes.
KIRK: You mean entry can be gained by playing certain notes on a musical instrument?
SPOCK: That would be one method. Another would be a series of tonal qualities spoken in their proper sequence.
KIRK: Give me your communicator. Tonal control, consonants and vowels. I must have hit it accidentally when I contacted the ship.
SPOCK: If you could remember your exact words, Captain.
KIRK: (flipping open the communicator) Kirk to Enterprise.
SCOTT: ON COMMUNICATOR- Aye, Captain. (The hatch slides open)
KIRK: Scotty, if the deflector isn't activated within twenty minutes, get out of orbit. Get the Enterprise out of the danger zone. The landing party is expendable. The Enterprise isn't. Kirk out...
IN THE OBELISK CHAMBER - SPOCK: It is similar to deflector panels I've seen, Captain, but far more complicated.
KIRK: Careful. I must have hit something accidentally. A beam caught me and that's when I stopped remembering.
SPOCK: Probably a memory beam. You must have activated it out of sequence.
KIRK: More symbols. Can you read them?
SPOCK: I do have an excellent eye for musical notes, Captain. They would seem to indicate that this series of relays activated in their proper order.
KIRK: Spock, just press the right button.
(Spock presses the middle button of a row of three, and other sections light up. A blue beam shoots out of the top of the obelisk and pushes the asteroid away.)
Asteroid deflectors; as the Great Bird of the Galaxy has told us, every planet needs one.
Scroll down for more stories in the same category. (Story submitted 1/12/2016)