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Beaming into Space

Posted by michael on from the do-not-look-into-beam-with-remaining-eye dept.

HobbySpacer writes "At this week's 1st Int. Symposium on Beamed Energy Propulsion in Huntsville a wide range of laser and microwave propulsion schemes are being presented. The big news so far is the announcement by Gregory Benford of plans for a test of microwave propulsion with the Cosmos Sail, due to fly early next year. The possibilities of using lasers to deflect incoming asteroids & comets are also under discussion."

3 of 124 comments (clear)

  1. Re:A simple proposal by TheOnlyCoolTim · · Score: 5, Interesting

    What we really need to do is convince some multi-billionare (like Bill Gates, Warren Buffet, or one of those Middle East Oil Sheiks) to jumpstart humanity's expansion into space out of their own pockets.

    Start with a space elevator, price tag 10 - 40 Billion dollars. Then maybe build a *NICE* space station on top of it, which should cost much less. Use the space station to build a spaceship for the purpose of bringing an insanely mineral rich asteroid back to Earth orbit. Establish a mining base on the asteroid.

    3. Profit.

    Tim

    --
    Omnia vestra castrorum habetur nobis.
  2. Re:Asteroid Deflection by pdp11e · · Score: 3, Interesting

    The site seems to be /.-ted and no karma-whore posted a reprint yet.
    So i did not RTFA. However to "deflect incoming asteroids & comets" with
    photons is ridiculous idea. Photons carry momentum h*nu/c and
    energy h*nu. One way to treat the problem is to consider a simple mechanical
    collision of photon and target (asteroid). I did a "back of an envelope calculation"
    and derived a following results:
    For the visible photons of 550 nm, a beam of 1 GW produces a force of 6.7 N (~ 1.5 lb).
    Now that is really going to take care of that 1 000 000 t asteroid.

    Now let's try another approach. Let's assume that the said 1 GW beam vaporizes surface of
    the asteroid and that "rocket effect" has 100% efficiency. 1 GW applied on the
    1 000 000 t body for the duration of say 86400 s (1 day), changes the body's velocity
    for 415 m/s. This is much better, particularly if the target is irradiated far away from the
    Earth. However, with the current technology it is feasible as much as the "tractor beam".

  3. Re:Why deflect Asteroids? by Spy+Hunter · · Score: 4, Interesting

    No, we should send out little tiny spaceships that shoot dots. Then we can shoot them into smaller asteroids that split into even smaller asteroids, and then those just disappear when you shoot them. I have lots of practice with this already.

    --
    main(c,r){for(r=32;r;) printf(++c>31?c=!r--,"\n":c<r?" ":~c&r?" `":" #");}