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Space

Easily-Captured Asteroids Identified 160

Posted by Soulskill
from the if-they're-any-smaller-you-have-to-throw-them-back dept.
Hugh Pickens DOT Com writes "Long overlooked as mere rocky chunks leftover from the formation of the solar system, asteroids have recently gotten a lot more scrutiny as NASA moves forward with plans to capture, tow, and place a small asteroid somewhere near our planet. Two different private space companies, Planetary Resources and Deep Space Industries, plan to seek out and mine precious metals and water from near-Earth asteroids. Now Adam Mann reports that astronomers have identified 12 candidate Easily Retrievable Objects (EROs) ranging in size from approximately 2 meters to 60 meters in diameter that already come (cosmically) close enough to our planet — close enough that it would take a relatively small push to put them into orbits at Lagrange points near Earth using existing rocket technology. For example, 2006 RH120 could be sent into orbit at L2 by changing its velocity by just 58 meters per second with a single burn on 1 February 2021. Moving one of these EROs would be a 'logical stepping stone towards more ambitious scenarios of asteroid exploration and exploitation, and possibly the easiest feasible attempt for humans to modify the Solar System environment outside of Earth (PDF),' write the authors in Celestial Mechanics and Dynamical Astronomy. None of the 12 ERO asteroids are new to astronomers; in fact, one of them became briefly famous when it was found to be temporarily orbiting the Earth until 2007. But until now nobody had realized just how easily these bodies could be captured."
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Easily-Captured Asteroids Identified

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  • Looks like it's time (Score:5, Interesting)

    by halltk1983 (855209) <halltk1983@yahoo.com> on Wednesday August 14, 2013 @07:18AM (#44563303) Homepage Journal
    Looks like it's time to build a foundry in space so we can begin the construction of satellites, space stations and long range spacecraft with materials readily available in space, so we don't have to keep carting it up there. Between that and robots and assembly machines, we should be able to build out stuff in the next couple decades.
    • by Thanshin (1188877)

      Or just send a micro 3Dprinter robot that can mine the asteroid and use the material to self-replicate.

      Dak Tak Lak Pak.

      • by morgauxo (974071)

        If you can think of a way to make a printer robot, with all it's moving pieces, electronics, etc... using nothing but rock and metal then you might have something there. I can't wait to see your motor windings made of rock insulated wire, asteroid derived lubricant, rock circuit boards, etc...

        • by FSWKU (551325)

          motor windings made of rock insulated wire, asteroid derived lubricant, rock circuit boards, etc...

          Sounds like the company is run by one of Mr. Slate's [wikia.com] descendants.

        • by Immerman (2627577)

          Electronics can be brought up from Earth, they're mostly small and light - at even $10k/pound delivery charge a cpu is only a few times more expensive than on Earth. A motor is a little pricier, especially a large high-power one if you needed such a thing, but still relatively cheap compared to a spacecraft. Most of the mass of any orbital structure will be (drumroll please) the structure. Girders, skin, shielding, etc. If we can print or otherwise manufacture a big reinforced steel can then the electron

          • by Russ1642 (1087959)

            Or you could simply dig a hole in it, pressurize it, and voila. There's your spaceship. Attach boosters and you're set.

            • by cusco (717999)
              Spin it and you've got pseudo-gravity as well. One proposal from the 1970s had the asteroid melted, spun, and then inflated like a balloon to create a habitat.
            • by Immerman (2627577)

              That assumes a pretty solid structure - from what I've heard the guesses are that most asteroids are a bit closer to a gravel pile than a block of granite. Still, it would make excellent sense to use the rock as radiation and micrometeorite shielding, you just might have to mix it (at least the outer layers) with some sort of binding agent first so that it doesn't get torn apart under serious acceleration.

    • Re: (Score:2, Interesting)

      by drinkypoo (153816)

      What do you propose to build the foundry out of?

      We need to capture one of these objects before we have the material to build the foundry!

      • by Thanshin (1188877) on Wednesday August 14, 2013 @07:52AM (#44563569)

        What do you propose to build the foundry out of?

        We need to capture one of these objects before we have the material to build the foundry!

        If only we had a large mass of material anywhere close by...

      • by halltk1983 (855209) <halltk1983@yahoo.com> on Wednesday August 14, 2013 @08:03AM (#44563675) Homepage Journal
        I don't mind launching the materials to build the initial foundry, it's that foundry which will provide the materials for the other ones. Everyone knows that's how you play an RTS.
      • Bootstrap. A minimal set of tools sent into orbit to build a bigger set of tools. Two or three iterations can have large scale foundries up and running, while building some other interesting things along the way.

    • Looks like it's time to build a foundry in space so we can begin the construction of satellites, space stations and long range spacecraft with materials readily available in space, so we don't have to keep carting it up there. Between that and robots and assembly machines, we should be able to build out stuff in the next couple decades.

      Time to start testing what a zero-g foundry should look and act like more likely. While we've done some fabrication and welding in space, I doubt we've tried the equivilent of anything like a foundry. Zero g and no atmosphere will make our usual methods unworkable. Hell, learning how to mine will be a huge undertaking with no gravity to hold bits down and collect them or for use as traction for vehicles or machinery. With the readily available solar power and energy, I suspect smaller rocks could be melted

  • by Anonymous Coward on Wednesday August 14, 2013 @07:26AM (#44563371)

    I know the article talks in relative terms - but changing a massive object's velocity by 58 m/s is not trivial. Also, this assumes the asteroid isn't tumbling or rotating. You would have to cancel this before actually attempting to move the object.

    • by Thanshin (1188877)

      It depends on how you push it. If it's by reflecting solar wind on it via parabolic mirror, you can leave its rotation alone until mining time.

      • by toastar (573882)
        58 m/s is for the calculated impulse delta-v. With a lower thrust maneuver, your total delta-v is higher. This is the problem with ion drives.
    • by Anonymous Coward

      but changing a massive object's velocity by 58 m/s is not trivial.

      That's why they picked 2006 RH120. With a 5m diameter, the mass should be somewhere around 500 tons, probably less. A lot of mass to move, but not impossible, I guess.

      • That's well within the capability of a conventional rocket, just in terms of thrust. The problem would be figuring out how to grapple the object and stop its rotation. If it's only 5m wide, you could probably just throw some kind of net around it. I wouldn't be surprised to see plans to capture this particular object starting to appear in the near future.

    • Also, this assumes the asteroid isn't tumbling or rotating. You would have to cancel this before actually attempting to move the object.

      Only if you need to attach 1 big rocket to object being captured.

      You could use a gravity tub approach, although it probably needs a small target to work.

      Or, you could put lots of smaller rockets all over the surface and just have them fire a quick pulse when they are facing the right way, that would have the added benefit of redundancy should a rocket fail.

    • by morgauxo (974071)

      "They calculate that this could be done with a single burn on 1 February 2021"

      This doesn't sound like a relative term to me. And it was even mentioned in the summary too!
      I'm not sure I would go so far as to say this means it is objectively easy. I suppose landing a rocket engine on an asteroid and using it to push is something that has never been done before. That alone means there will be challenges to overcome. With only one push necessary though.. that's about as easy as one could realistically imagin

    • by Kookus (653170)

      A shuttle is 4 and a half million pounds. and is fighting Earth's gravity. If the largest rock in the summary was picked, it'd weight less than 1 million pounds on Earth (more like half a million).
      Changing its velocity by 58m/s is actually technologically trivial. Rotation isn't so bad either, you just pulse your burners. The article just says single burn to give you a nice number.
      More than likely, they'd send up 3 - 6 rockets for redundancy and to stabilize the rock's rotation in a few bursts. Then they'd

    • by Immerman (2627577)

      In space terms it is - raise something to orbital height and you still need to get it going 8,000m/s to stay up.

  • Easily captured... (Score:4, Interesting)

    by runeghost (2509522) on Wednesday August 14, 2013 @07:44AM (#44563483)
    or easily retargeted to hit DC? How long before the politicians demand trillions on behalf of their owners to protect the U.S. from the "asteroid threat". War on Space, here we come!
    • by Thanshin (1188877)

      An asteroid that size wouldn't reach land.

      (However, the US has never needed the threats to be non-fictional to scare its population into giving up freedom and money.)

      • by AmiMoJo (196126) *

        A few of them bunched together, or with a heat shield attached might.

        It wouldn't surprise me that much if the first company to capture an asteroid finds all manner of space "junk" headed for it's installation, or perhaps the odd missile from the ground if countries feel threatened enough.

  • 58 Second Burn? (Score:3, Insightful)

    by Dialecticus (1433989) on Wednesday August 14, 2013 @07:56AM (#44563599)
    And what happens if, due to a malfunction, the thruster doesn't shut off when it's supposed to, and it burns for longer than 58 seconds?

    People got angry about BP, and before that the Exxon Valdez, but that was after the accidents had already happened. What happens when a greedy grab for extraterrestrial ore inevitably goes awry? And make no mistake; over the long hault, it is inevitable. Even if the first attempt, hell the first five such attempts, go off without a hitch, there would eventually, over many such attempts, be a critical error on a similar mission.

    There would be no time for recriminations and lawsuits then.
    • by Thanshin (1188877)

      And what happens if, due to a malfunction, the thruster doesn't shut off when it's supposed to, and it burns for longer than 58 seconds?

      What's your worst case scenario?

      OMG! The asteroid hits Earth AND!!!! ... fizzles in a puff of smoke, like the other thousands that hit Earth every day.

    • And what happens if, due to a malfunction, the thruster doesn't shut off when it's supposed to, and it burns for longer than 58 seconds?

      It would just run out of fuel. It is so expensive to hurl any mass into space that you do not take anything extra with you. The main thing that could go wrong is that the direction of the thrust is wrong or that you blow the asteroid to pieces.

    • Re:58 Second Burn? (Score:5, Informative)

      by HawkinsD (267367) on Wednesday August 14, 2013 @08:32AM (#44563981)

      Well, let's consider the damage from the impact of a rocky asteroid, 60m in diameter. Plug this into the excellent Earth Impact Effects program at http://impact.ese.ic.ac.uk/ImpactEffects/. Assume a velocity of 17 km/s, which they say is "typical for asteroids," and an impact angle of 45 degrees.

      The calculator says:

              The projectile begins to breakup at an altitude of 54000 meters = 177000 ft
              The projectile bursts into a cloud of fragments at an altitude of 4700 meters = 15400 ft
              The residual velocity of the projectile fragments after the burst is 4.77 km/s = 2.96 miles/s
              The energy of the airburst is 4.52 x 1016 Joules = 1.08 MegaTons.
              No crater is formed, although large fragments may strike the surface.

      Clearly you wouldn't want to be right underneath it, but even as close as 20 km, the air blast effects seem rather anticlimactic:

              Peak Overpressure: 18900 Pa = 0.189 bars = 2.69 psi
              Max wind velocity: 41.4 m/s = 92.6 mph
              Sound Intensity: 86 dB (Loud as heavy traffic)
              Damage Description:
                      Glass windows will shatter.
                      About 30 percent of trees blown down; remainder have some branches and leaves blown off.

      So it'd be like BOOM! But not like KA-FOOOM!

      For comparison, the Chelyabinsk meteor was estimated at 17-20m, with an airburst energy of 0.4 MegaTons.

      • And that's if it even hits Earth. If the rockets burn too long they may push the asteroid too far so that it gets flung out to space (gravitational slingshot around Earth). I'll worry if we decide to capture HUGE asteroids on our first go around, but 60 meters large asteroids seem to be an extremely low risk.

      • by Rhacman (1528815)

        So it'd be like BOOM! But not like KA-FOOOM!

        So what you're saying is it would be like a Fus without the Ro Dah?

      • For comparison, the Chelyabinsk meteor was estimated at 17-20m, with an airburst energy of 0.4 MegaTons.

        Plus there is a huge difference in speed between something in orbit and something that zips in from the Kuiper belt.

    • by robbak (775424)

      They are trying to hit an earth-sun lagrange point. If they do so, the object leaves its solar orbit and enters an unstable earth orbit. They then need to give it another few burns to stabilize the orbit (and keep it away from the lagrange point, which would allow it to leave earth orbit and resume orbiting the sun) . If they miss, then it travels on, on a different orbit, with roughly the same chance of hitting the earth as it ever did.

    • by gman003 (1693318)

      The asteroids being considered are roughly the size of the Chelyabinsk meteor. It's highly unlikely one would make it to the ground. You could still get a similar air-blast, but the odds are pretty good that it won't hit a populated area (remember, three-quarters of the Earth is water).

    • by jasax (1728312)
      To give a practical perspective on meteor sizes, recall that the Chelyabinsk meteor which arrived at Russia this same year had around 15-20 m of diameter
      http://en.wikipedia.org/wiki/Chelyabinsk_meteor [wikipedia.org]

      And the space rock that carved Meteor Crater (or Barringer crater) in Arizona, around 50 K years ago, had about 40 meters of diameter.
      http://www.space.com/834-mystery-arizona-meteor-crater-solved.html [space.com]

      So, a 60 meters meteor will probably create a big, big, hole (depending on the velocity at arrival an
    • Perhaps you plan your burn so the asteroid is never on an earth intercepting trajectory? Shouldn't really be that hard. And if something goes really and truly wrong you detonate the rocket. It was good enough for all the live warhead nuclear missile tests we've done; aim away from anything important, keep your finger on the abort button.

    • by jxander (2605655)

      There are some pretty simple engineering solutions for the problem. One quick example, give the ship 2 different fuel tanks (and possibly 2 different sets of thrusters) One fuel tank and thruster set gets us to the asteroid, at which point it shuts down. The 2nd set provide delta-v towards earth, only having enough fuel to get it into position (with maybe a bit extra, just in case... but not enough extra to crash into us)

      In the long run, we'll probably move production away from earth. I wonder if Mars

    • by splutty (43475)

      They want to move it to L2, it's not going to be anywhere near the earth to bother with.

      If the thruster runs too long, it'll overshoot L2, and go into an orbit rather far out of the moon's orbit.

      Chance it crashes on the moon is rather higher than it crashing on earth, and even then it'll not be an overly significant event (see someone else's calculations in this reply thread as well)

      L2 is perfect for this stuff, since it's actually outside the earth's sun orbit and farther away than the moon.

      Now L3,4,5 whic

  • This is insane. Let them first develop 100.00000000000%-reliable-accurate-faultless technology before putting the entire planet .. every lifing thing on or above earth .. at serious risk of vaporization. These people ought to be institutionalized ...
    • Re: (Score:2, Insightful)

      by Anonymous Coward

      Judging by the comments, who would have thought the population of slashdot is 50% luddites. Seriously, this is why you start on small asteroids. A 2m rock is going to burn up in the atmosphere.

    • Thank goodness, a level-headed, rational viewpoint.

      Come have a beer with me - drive your 100.00000000000000% reliable and totally safe car to my neighborhood.
    • by Immerman (2627577)

      What risk? Even if we screwed up in the worst possible manner and it collided with the Earth (a vanishingly small probability within the space of all possible screw-ups, most of which would send it sailing merrily past us), a 60m asteroid traveling at roughly the same speed and direction as the Earth would be unlikely to reach the surface to leave a crater. Some fragments might, and you probably wouldn't want to be directly underneath the fireball as it burnt up/detonated in the atmosphere, but even then

    • by maliqua (1316471)

      This is insane. Let them first develop 100.00000000000%-reliable-accurate-faultless technology before putting the entire planet .. every lifing thing on or above earth .. at serious risk of vaporization.

      These people ought to be institutionalized ...

      you are stupid.

  • by rhazz (2853871)
    Can't we just get Sephiroth to use the black materia to summon Meteor? That pulled in an asteroid pretty damn quickly IIRC...
  • by Squidlips (1206004) on Wednesday August 14, 2013 @08:31AM (#44563979)
    I did not know it was such a precious commodity...seems legit.
    • Water is extremely precious in space .

    • by Immerman (2627577)

      The SpaceX Falcon Heavy is planned to deliver payload to low Earth orbit for the astoundingly low price of $709/lb. It's maximum payload to geosynchronous transfer orbit is less than half that to LEO (21 vs 53Mg), and I'm guessing the total launch cost is probably about the same, so call it $1800/lb. To Mars the maximum payload is 13Mg, or $2900/lb (which is actually much closer to last-years costs to LEO, so Mars is getting a lot more accessible than it used to be).

      At any of those prices though *everything

    • Re:Mining water? (Score:5, Insightful)

      by someone1234 (830754) on Wednesday August 14, 2013 @10:48AM (#44565277)

      It's probably the most precious commodity in space.

      • by RockDoctor (15477)

        It[WATER]'[i]s probably the most precious commodity in space.

        Old "joke" from avalanche rescue workers : you can live for 3 months without food, 3 days without water, but only 3 minutes without air!"

        Ha ha, but serious.

  • In all fairness, it does sound a wee bit like the start of disaster sci-fi movie. An interesting one even. Some asteroids, massive amounts of greed, a cute alien race risking their life and limb for our increasingly idiotic and helpless humanity.
  • by maliqua (1316471) on Wednesday August 14, 2013 @01:03PM (#44566793)

    Your a bunch of pussies 1. the asteroid sizes they're talking about would have no significant affect in any failure scenario, well perhaps if it actually HIT the ISS or a satellite but thats not likely. The size of asteroids they want to mine would almost entirely burn up in the atmosphere if it did miss and enter earth.

    This is the exact thing we need to be doing we cant exist on earth forever, even if we had 0 environmental impact as a race the planet would eventually expire. Exploiting extra-planetary resources and colonizing space are the most important goals that could ever exist for us as a race. Only those things can provide us a chance at keeping the human race alive in perpetuity

  • How much effort would it require to move the "left overs" out of Lagrange? Or do we start fusing the remains at Lagrange to start building a habitable facility?
    • by RockDoctor (15477)
      "Yes"

      To both options.

      If you have significant residue, then "bag it" and park it somewhere (e.g., nearby). If you need it again (including as reaction mass for a mass-driver), then it's to-hand. If you really need to tidy up the environment, drop it -60km/s of heliocentric delta-vee and it'll soon enough be plasma.

      Remember that the Lagrangian points are "points" only when all of (Sun, Earth and Moon are perfect spheres) AND Jupiter and the rest of the Solar System don't exist AND lots of other things.

      Obj

  • What percentage of these bodies has valuable metals? One thing to consider is that most of the economic deposits of the Pt-Group Metals, such as the Bushvesd, Skargard, and Stillwater Complexes are probably astroblems from the post Great Bonbardment era in which asteroids give the Earth their heavy metals after it had the heat to concentrate these in the core. They remained in the crust. This may also apply to Au and related metals as well.

    It would seem to me to be important to find those bodies that are

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