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Space

Ask Slashdot: Best Payloads For Asteroid Diverter/Killer Mission? 150

Posted by Soulskill from the four-micrograms-of-nanites dept.
TheRealHocusLocus writes: The Emergency Asteroid Defence Project has launched a crowdfunded IndieGoGo campaign to help produce a set of working blueprints for a two-stage HAIV, or Hypervelocity Asteroid Intercept Vehicle. This HAIV paper (PDF) describes the use of a leading kinetic impactor to make a crater — a following nuclear warhead would detonate in the crater for maximum energy transfer. The plans would be available for philanthropists to bring to prototype stage, while your friendly local nuclear weapon state supplies the warhead. This may be a best-fit solution. But just ask Morgan Freeman: these strategies could fail. What — if any — backup strategy could be integrated into an HAIV mission as a fail-safe in case the primary fails? Here is a review of strategies (some fanciful, few deployable) if we have to divert an asteroid with very short lead time. A gentle landing on the object may not be feasible, and we must rely on things that push hard or go boom. For example: detonating nearby to ablate surface materials and create recoil in the direction we wish to nudge. Also, with multiple warheads and precise timing, would it be possible to create a "shaped" nuclear explosion in space?
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Ask Slashdot: Best Payloads For Asteroid Diverter/Killer Mission? More

Ask Slashdot: Best Payloads For Asteroid Diverter/Killer Mission?

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  • Discovery of an underwater skeleton 'tea party' in the Colorado River [ktla.com] provides ample proof that the human race is worth saving.

    • Re:In defense of the human race (Score:5, Funny)

      by JaredOfEuropa ( 526365 ) on Saturday May 16, 2015 @06:11PM (#49707819) Journal
      That is just too funny. In the same spirit, I suggest we send up Celine Dion and Justin Bieber on that asteroid buster mission. They won't be of any help when things go wrong, but if the primary mission succeeds, we will not only have won back out world, we will have made it a better place.

      • We have a winner.
        If you send Celine Dion and Justing Bieber up on an incoming asteroid, it will steer away on its own.

        • But by that logic one could argue the reason we haven't been hit by a big asteroid is /because/ Bieber and Dione are here on Earth. The asteroids have been steering clear of us rather than risk contamination. Ship Bieber/Dione out into deep space and we lose that protection!

          Then again, it might be worth it...

  • the dinosaurs tried everything.

  • I'd love to see them fly into an asteroid.

    • I'd love to see them fly into an asteroid.

      Great idea! In the spirit of the underwater skeleton 'tea party' in the Colorado River [ktla.com], in tribute to the artist -- space permitting -- it would be really cool if a large unmanned asteroid intercept vehicle could have a windowed 'bridge' with a pair of plastic skeletons seated in lawn chairs. Their grinning skulls would be the last thing that nasty old space rock ever sees.

      You get points for style.

  • Then when an killer asteroid is found, just push the moon in the way.

    (Yes, I know that can't work. But it won't stop Hollywood from using it in a movie.)

  • In atmosphere, nukes produce blast because of high energy x-rays igniting atmosphere. This won't happen in space.

    So how would letting off a nuke near or on an asteroid produce reaction and change the course of the asteroid?

    • Re: (Score:3, Informative)

      by Anonymous Coward

      The Orion project looked at how to push a large object with an explosion in a vacuum.
      Project_Orion_(nuclear_propulsion) [wikipedia.org]

    • In atmosphere, nukes produce blast because of high energy x-rays igniting atmosphere. This won't happen in space.

      So how would letting off a nuke near or on an asteroid produce reaction and change the course of the asteroid?

      Basically, the x-rays will ignite the surface of the asteroid instead. If the material in the asteroid is sub-optimal for this purpose, there have been designs of turning a nuclear bomb into a kinetic weapon that should work in this regard. Basically the bomb sits in an x-ray reflective shell, and when the bomb explodes, the x-rays bounce around the shell before the exploded bits of the bomb destroy it and exit an aperture. At the end of the aperture is a large, dense block of x-ray absorbing material. This

      • In atmosphere, nukes produce blast because of high energy x-rays igniting atmosphere. This won't happen in space.

        So how would letting off a nuke near or on an asteroid produce reaction and change the course of the asteroid?

        Basically, the x-rays will ignite the surface of the asteroid instead. If the material in the asteroid is sub-optimal for this purpose, there have been designs of turning a nuclear bomb into a kinetic weapon that should work in this regard. Basically the bomb sits in an x-ray reflective shell, and when the bomb explodes, the x-rays bounce around the shell before the exploded bits of the bomb destroy it and exit an aperture. At the end of the aperture is a large, dense block of x-ray absorbing material. This material is vaporized by the x-rays and is all traveling in a similar direction as the x-rays were all going in that general direction. This plasma moving at relativistic speeds then slams into the target like a nuclear shot gun blast. IIRC, this design was built for using nuclear bombs against space ships and it was estimated that it could direct 95% of the energy of the bomb at the intended target.

        Thanks, thats a nice explanation!

      • Basically, the x-rays will ignite the surface of the asteroid instead. If the material in the asteroid is sub-optimal for this purpose, there have been designs of turning a nuclear bomb into a kinetic weapon that should work in this regard. Basically the bomb sits in an x-ray reflective shell, and when the bomb explodes, the x-rays bounce around the shell before the exploded bits of the bomb destroy it and exit an aperture. At the end of the aperture is a large, dense block of x-ray absorbing material. This material is vaporized by the x-rays and is all traveling in a similar direction as the x-rays were all going in that general direction. This plasma moving at relativistic speeds then slams into the target like a nuclear shot gun blast. IIRC, this design was built for using nuclear bombs against space ships and it was estimated that it could direct 95% of the energy of the bomb at the intended target.

        I second that. Masterful tech writing.

        This description of Orion propulsion also describes the 'Casaba-Howitzer' [projectrho.com], a one-shot Orion optimized for a narrow, fast plasma jet. Here objective is more similar to Orion than punching through armor: the most complete, reliable and (as much as possible) directed transfer of energy. The Casaba-Howitzer concept is not even in the declassified SDI [wikipedia.org] flava stuff that DOE is permitted to talk about [osti.gov].

        We all love Delta-V-expensive solutions that involve maneuvering 'beside' or

  • Moon rocks (Score:5, Insightful)

    by Anonymous Coward on Saturday May 16, 2015 @06:26PM (#49707875)
    You need a moon base (not manned) to do this right. Then you throw moon rocks at the impending impactor. Doing it from a smaller gravity well means you can sling them into space more easily via something like a magnetic rail gun (yes, you need to put the moon rocks into a container made of iron / steel so it works with a mag solution).

    • Re:Moon rocks (Score:4, Informative)

      by TheRealHocusLocus ( 2319802 ) on Saturday May 16, 2015 @06:48PM (#49707965)

      You need a moon base (not manned) to do this right. Then you throw moon rocks at the impending impactor. Doing it from a smaller gravity well means you can sling them into space more easily via something like a magnetic rail gun (yes, you need to put the moon rocks into a container made of iron / steel so it works with a mag solution).

      +1 Insightful

      A series of mass-produced kinetic impactors launched from the lunar surface by an EM rocket sled [wikipedia.org], each a ferrous metal cylinder containing lunar regolith with some propellent, attitude jets for course correction, (perhaps) a main engine for additional impact velocity. The probability of several or many reaching target is high. I give you a gold star. We could even retaliate against Mars.

      It could be used to target Earth too, let's hope to be mature enough to resist. And hopefully its accuracy is better than Popeye's Pappy as he attempts a warning shot across the bow [youtube.com].

      • Re: (Score:3)

        by dwywit ( 1109409 )

        "The moon is a harsh mistress" is a good reference for this.

    • Re: (Score:2)

      by quenda ( 644621 )

      It is easy to get out of the earth-moon gravity well from the moon with a sled, but your load will still be stuck in a solar orbit similar to the Earth's.
      To divert an asteroid, you would need to catch it early, on a near-miss pass of the Earth, and even then the orbit will still intersect our orbit.
      If we detect a large object on a direct collision course, launching rocks at it from the moon is about as useful as throwing rocks by hand at an incoming ICBM.

      • ICBM's have guidance systems. Asteroids and comets do not, and space is _large_. Even a very, very slight "delta vee" early in the trajectory will make it miss a planet quite easily.

  • Confetti
    ?

  • If you have enough lead time then I think the gravity tug works well. You rendezvous with the asteroid and fly alongside it, using solar-electric or some other slow but mass-efficient drive to hold station on the same side of the asteroid. The gravity of the probe VERY SLOWLY accelerates the asteroid and over a few decades (perhaps with a few refueling missions to bring more xenon or whatever) the asteroid's orbit is changed enough to miss the Earth,.

  • NASA's current plan it to cover a sufficient amount of the object with a different colored cloth (white or black as the case may be) and let the solar sail effect do the work. So a 30% off coupon to Bed Bath & Beyond would do the trick; even with the discount the manager and staff should get a nice bonus for selling 250,000 white sheets in one day.

    sPh

    • Only works if the asteroid cooperates by not tumbling.

    • You can get a much, much larger effect by attaching a much larger, more easily manufactured and testable actual solar sail. Either approach has interesting difficulties if the object is tumbling, since the attachment points for a solar sail or an actual elevated shield would need to be at the axes of rotation with joints that can handle spinning. And any mishandling of the forces could change the tumbling and cause the object to precess. But that seems far, far simpler than stopping the tumbling completely:

      • You can get a much, much larger effect by attaching a much larger, more easily manufactured and testable actual solar sail.

        How are you going to do that attachment again? The attachment mechanisms for Philae worked spectacularly well given the amount of information that was available about the comet's surface structure ten years before contact. So we can realistically anticipate a similarly accurate degree of knowledge about the surface properties of the asteroid we need to manage in two years time.

        Next sug

        • Philae did not have to apply significant force to the comet itself, especially applying consistent force as the comet itself melts, and to consistently apply force to the same side of the comet. Even if a solar sail is applied purely as a solar powered brake, the tumbling of a comet or asteroid will require that the attachment points be able to _spin_, and not to tangle the shrouds of the solar sail on the tumbling object itself. If the spin of the object has an axis on the side away from the Sun, it should

          • I'd anticipate significatnt sublimation and thawing on even the backside if the solar sail does not reflect _away_ from the object.

            Since at least some comets that cross Earth orbit (and are therefore a threat) have had insignificantly altered orbits for several thousand years and dozens of perihelia, then the lower limit of sublimation you're going to need to consider is under 1% per apparition. Even with a solar sail blasting the backside with essentially another Sun, you're still down in the 2% per appa

            • > I agree on this point. But since the proposal is for a generic design to deal with any incoming impactor, be it comet, asteroid, or even generation ship, then a design that can handle any impactor without modification is needed. There won't be time to design a modification if it is actually needed.

              And this is where I would say _what!!???_ at lest if we were in person. "Any incoming impactor" includes objects of such potentially high kinetic energy, and of such unlikeliness, that we cannot even include

  • Any chance that you might consider posting "Ask Slashdot" articles in the "Ask Slashdot" section in the future? Please?

    • Any chance that you might consider posting "Ask Slashdot" articles in the "Ask Slashdot" section in the future? Please?

      I believe the proper forum for this question is "Ask Slashdot". Please re-post your question there.

  • ablation by laser (Score:4, Interesting)

    by bzipitidoo ( 647217 ) <bzipitidoo@yahoo.com> on Saturday May 16, 2015 @07:02PM (#49708017) Journal

    Beam enough laser light at the object to heat its surface to the point that it ablates. That will push it onto a different course. We won't even have to leave Earth for that to work. Of course, it does need an awful lot of laser power, but if our very survival is at stake, maybe we could do it. Here's the relevant XKCD what if [xkcd.com].

    • Beam enough laser light at the object to heat its surface to the point that it ablates

      Another extreme light solution, also reliant on melting its surface are giant parabolic mirrors deployed near the object. This interesting discussion [nasaspaceflight.com] points out some of the realities of gathering and focusing sunlight.

      Once our civilization hits Stage 1.5 on the Kardashev scale [wikipedia.org] we might revisit an idea proposed in 1993 by Paul Birch, How to Move a Planet [orionsarm.com] through the use of what he calls a 'solar windmill' to transfer angular momentum between the sun and planets. It's Rube Goldberg as hell!

      "We conclude that through the use of high-velocity dynamic compression member to apply forces efficiently, planetary orbits can be modified on convenient engineering timescales ~30 years, that the cost of such operations is not excessive in conjunction with terraforming or artificial-planet-building projects, that energy can be converted to and from orbital energy with little loss, and that the technique may also apply to the regularisation of stellar motions."

      Then we could just

  • Obviously (Score:3)

    by rossdee ( 243626 ) on Saturday May 16, 2015 @07:20PM (#49708105)

    Bruce Willis

  • How about shooting some tethers at it and deploying a counter-weight (rocket-powered?) to the object to swing it out of orbit? Make it into a Bola?

    • How about shooting some tethers at it and deploying a counter-weight (rocket-powered?) to the object to swing it out of orbit? Make it into a Bola?

      David French proposes Trajectory Diversion of an Earth-Threatening Asteroid via Massive, Elastic Tether-Ballast System [2010] [enu.kz], although the time frame for the large objects he modeled was upwards of a decade. But IF you do have decades and the materials challenges of the tether (bluntly pointed out in Wired Magazine [2009] [wired.com]) are solved, it offers a low-tech solution that would not require constant vigilance or active control.

      Or a massive light saber flung with a cosmic atlatl.

    • The object is likely spinning. I'd want to eliminate the tether, which is huge point of failure. While static loading isn't as big an issue, shock loading IS a big problem, and it's unlikely we'll be able to entirely prevent it, or it will be prohibitively expensive in terms of mass (fuel for burns to slowly load the tether). Either way, you'll need to match the spin (i.e., orbit around) the object in order to eliminate the relative motion.

      Also, I have no idea how much force you would need to perturb the or

  • Would it be more efficient to launch an impactor from Earth to change the asteroid's trajectory or to launch a rocket (using the same rocket that would launch the impactor) carrying a second rocket that would attach to the asteroid and burn to similarly change its trajectory? An impactor would need to be calculated precisely in advance, while attaching a rocket would allow some room for error since its burn could be controlled remotely. The actual feat of getting the rocket to land and securely mount itself

    • Paint

      Paint one side of the object white and it will change its orbit

      This would work with anything that we catch a few years out and would even produce results that could be calculated

      Sure, it is not as exciting as blowing shit up, but way more effective

    • Re: (Score:2)

      by flink ( 18449 )

      Would it be more efficient to launch an impactor from Earth to change the asteroid's trajectory or to launch a rocket (using the same rocket that would launch the impactor) carrying a second rocket that would attach to the asteroid and burn to similarly change its trajectory? An impactor would need to be calculated precisely in advance, while attaching a rocket would allow some room for error since its burn could be controlled remotely. The actual feat of getting the rocket to land and securely mount itself would be a challenge however. I don't think "blowing it up" is a good idea, but diversion if possible seems the least-risky and most-effective method.

      Just my take, but: If you want to land on it instead of crashing, you have to carry a bunch of extra fuel to burn off the delta-V that got you there in the first place. If you have enough extra fuel to slow down, you might as well burn it getting there faster so you have more energy when you impact. Essentially if you slow down to land, you're wasting a bunch of energy in the form of the ship's momentum which you could be putting into changing the course of the asteroid.

  • Hmm (Score:1)

    by koan ( 80826 )

    Multiple war heads detonated in a timed fan or "J" shape (asteroid on inside of curve) each adding more angular velocity.

    Radioactivity is less of a concern than a large strike on Earth's surface.

    I think the concern is moot though, the defrosting of Siberian tundra and other "accelerated" green house gas emissions, the acidification of oceans and the loss of most, if not all, of Earth's rivers will reduce the human population to the point this would not be possible.

    Unless a strike is imminent.

    • Not quite what you suggested, but I had the amusing idea of spinning the thing up until it can't hold itself together. Probably not feasible and probably not a great idea if you don't manage to break it into small enough chunks...

  • Several hundred megatons of newborn kittens with milky whiskers.

  • Launch a similarly massed object at it made of antimatter.

  • Maybe a chuck Norris body part, fingernail clipping, chest hair something like that to bring the asteroid to its knees. Or simply beam a chuck Norris TV show at it, make it just not want to come here.
  • The White House, and Congress

  • Solar sail with a modest angle to the sail (Score:5, Interesting)

    by Antique Geekmeister ( 740220 ) on Saturday May 16, 2015 @09:44PM (#49708727)

    Solar sails are light payload, the forces involved are modest and cumulative rather than requiring a single controlled thrust under extreme circumstances, and need only modest anchorage or very modest netting to attach to the asteroid. They can provide continuous thrust for the lifespan of the sail, rather than a single high energy event, so they're much safer to build and to handle and much, much safer to test. Attached early enough, they should easily shift an asteroid or comet enough to avoid a crash. And properly constructed, they could be used to guide the object to almost any orbit desired, including guiding it to L4 or L5 to be a resource.

  • Yes, it is entirely possible to create a nuclear shaped charge. The Orion project [wikipedia.org] was going to use quite a bit of them to launch a spacecraft with a payload of 6100 Tons to 300 Mile Low Earth Orbit.

    • Impulse is provided by soft X-ray ablation. X-ray production and dispersal can be tuned by:

      X-ray window on the radiation case
      The majority of the radiation case is lined with standard X-ray reflector material. An area of the radiation case is more X-ray transparent, giving some directionality to X-ray radiation previous to explosive dissassembly of the device.

      X-ray lasing medium
      Lasing rods are installed on the device to selectively produce X-ray photons when energized by a nuclear detonation, again previous

  • Lawyers. Then we can get down to the business of building something to save us.

  • NASA already has the answer. Glitter filled Super Balls [wikipedia.org] are the best thing for the job. As we all know, they are infused with magic energy. A 10kg payload traveling at 11.2 km/s could deflect an object the size of the moon.

    It does have risks though. Once set in motion, the Super Balls would be set loose on the universe, potentially disrupting entire galaxies.

    For the sake of the universe, I hope we never have to deploy such a weapon.

  • I like this [halfbakery.com] idea better.

  • Why bother with Morgan Freeman or Indiegogo for asteroids when there is real information out there.

    What are asteroids (90 minutes with a NASA expert):
    https://www.youtube.com/watch?... [youtube.com]

    What can we do against asteroids (again 90 minutes with an expert):
    https://www.youtube.com/watch?... [youtube.com]

    Form your opinion after you see these.

    • Why bother with Morgan Freeman or Indiegogo for asteroids when there is real information out there.

      [...] What can we do against asteroids (again 90 minutes with an expert):
      [Dr. Stan Love's NEA lecture] [youtube.com]

      Great informative lecture I hadn't seen before. But why might I decide to feature a link to IndieGoGo campaign and Morgan Freeman instead of headlining it...? Good question.

      Well for one thing, the Emergency Asteroid Defence Project and the IndieGoGo campaign represents a group of people who have decided the threat is actionable and has decided on a specific course of action. People in motion -- regardless of skill set -- will always be the greatest arbiters of change. If the mere presence of a good lectu

  • Don't carry payload into orbit - it's phenomenally expensive. Instead, gather mass that's already up there using lightweight automata. Then accelerate it, and keep it in a parking orbit. Rinse & repeat. The best way to shift mass is with mass. It doesn't really matter what it is. It's also far safer to manipulate mass than it is to manipulate nuclear charges.

  • Or at the very least only raises more.

    1. How big is the asteroid?
    2. What is it made of?
    3. How fast is it traveling?
    4. How far away from the Earth was it when first detected?

    I would say we would need to have many different strategies in place based on a mix of those variables.
  • It seems NASA did fund this concept... for a while, see citation here [nasa.gov]. Why did they stop this effort? Because of budget priorities? Politics? Or maybe it was a bad idea?

  • Bruce WIllis and a motley crew of oil riggers

  • the hot air coming from that gasbag would send the asteroid into a different direction

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