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Air Bags for Planetary Defense

Posted by michael on from the seat-belts-and-infant-seats-also-available dept.

Gallowglass writes "The Canadian paper, the National Post, is reporting on a plan to divert asteroids headed towards Earth. According to the story, the proposer, a Dr. Hermann Burchard, suggests deploying an inflatable mylar bag a few kilometers in size, and using it to push the projectile aside. An air bag for earth? The deployment mechanism isn't detailed in the story."

3 of 248 comments (clear)

  1. Air bag, eh? by Radi-0-head · · Score: 1, Interesting

    The engineering required to inflate Rob Malda to several kilometers wide must be mind boggling...

  2. Nukes for asteroid deflection by XNormal · · Score: 3, Interesting

    I once did some back-of-the-envelope calculations about deflecting asteroids with a physicist friend of mine.

    Our presumed target was a 1 mile dinosaur killer that is about to hit Earth in a few months and we want to impart enough kinetic energy to change its trajectory so that by the time it reaches Earth it will miss it by a few thousand miles of safety margin.

    Well, it turns out that it takes so much energy that even the biggest thermonuclear devices barely have enough energy to do it, even assuming we could convert it efficiently to kinetic energy.

    A nuke going off in space is just a big flash. No real blast. You need some working mass to convert it to kinetic energy. Using the mass of the asteroid itself is dangerous because you don't want it to break into multiple fragments.

    Here our calculations probably become much less accurate because we took some shortcuts and made some assumptions that may be way off, but the result we got is that we needed to send some tens of thousands of tonnes of working mass (e.g. water) along with the nuke to convert its energy to momentum with reasonable efficiency.

    Needless to say, this is beyond our current launching capabilities.

    --
    Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
    1. Re:Nukes for asteroid deflection by io333 · · Score: 2, Interesting

      Here our calculations probably become much less accurate because we took some shortcuts and made some assumptions that may be way off, but the result we got is that we needed to send some tens of thousands of tonnes of working mass (e.g. water) along with the nuke to convert its energy to momentum with reasonable efficiency.

      Needless to say, this is beyond our current launching capabilities.

      With the Orion it is not. I have a feeling that if there were a dinasaur killer on the way, an atomic powered launch vehicle would be be more politically correct.