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NASA Is Going To Crash a Satellite Into an Asteroid (fortune.com)

The National Aeronautics and Space Administration (NASA) is moving ahead with plans to try out deflection techniques on a passing asteroid to prepare for future, threatening space matter. From a report: The space agency has entered the preliminary design phase for its Double Asteroid Redirection Test (DART). This represents the first trial of what's called the "kinetic impactor technique" of asteroid deflection. Put another way, NASA hopes that by hurling a refrigerator-sized spacecraft at one of the space rocks at a speed roughly nine times that of a bullet, it can knock the asteroid off course and save the Earth. The plan is to launch the first DART satellite at a binary asteroid called Didymos ("Twins"); the twin asteroids are scheduled to pass by earth in 2022 and 2024. (Neither pass poses any threat, according to NASA.) By striking one of the two asteroids, scientists will be able to measure the impact of the collision.

42 of 89 comments (clear)

  1. "What could possibly go wrong?" by Jhon · · Score: 5, Interesting

    ... said the Saurian physicist about 65 million years ago.

    1. Re:"What could possibly go wrong?" by Big+Hairy+Ian · · Score: 1
      This is why they are impacting an asteroid that is already orbiting another larger asteroid

      1 They can park an orbiter to monitor the effects

      2 The impactor will only make a slight change in it's existing asteroid centric orbit thus preventing any significant change in it's solar orbit.

      --

      Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.

  2. dead for tax purposes by Thud457 · · Score: 1

    "What," said Trillian in a small quiet voice, "does asteriodcrash mean?"
    "It means," said Marvin, "that the probe is going to crash into the asteroid. Asteroid. . . . Crash. It's very simple to understand. What do you expect if you steal Hotblack Desiato's stuntprobe?

    --

    the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff

  3. Manned? by Anonymous Coward · · Score: 1

    or Unmanned?

  4. they take out the HBO satellite! by Joe_Dragon · · Score: 1

    they take out the HBO satellite!

  5. I predict AEAOR by Anonymous Coward · · Score: 1

    I predict "an equal and opposite reaction"

  6. Yup! What could go wrong? by 140Mandak262Jamuna · · Score: 2

    The plan is to launch the first DART satellite at a binary asteroid called Didymos ("Twins"); the twin asteroids are scheduled to pass by earth in 2022 and 2024. (Neither pass poses any threat, according to NASA, as long as refrigerator sized hard metallic objects are not slamming into the agglomeration of rocks and ice held together with weak gravity ) By striking one of the two asteroids, scientists will be able to measure the impact of the collision and be the first one to hide under the desks, like school children in cold war era, if the deflected asteroids home in on us

    Fixed it for NASA.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
    1. Re:Yup! What could go wrong? by MightyYar · · Score: 4, Funny

      Don't be worried about the one they hit - be worried about it's angry, defensive twin.

      --
      W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
    2. Re:Yup! What could go wrong? by rtb61 · · Score: 1

      The nature of the asteroid is just another thing to be taken into account. Dense heavy and you are really battling inertia and of course light easy to penetrate means you might pass through but you will still transfer energy into it (if you understand the compression and resistance to penetration and how it distributes to the rest of the mass, you will understand quite a lot is transferred.

      The advantage of a purely kinetic versus nuclear, is that if you fuck it up, you will still get hit but at least you will be less likely to scatter radio active mass all over the atmosphere. Assuming of course the meteor itself ain't radioactive. Also a solid kinetic dart could be fired by a very long barrelled steam cannon with multiple ignition points or more accurately many solid kinetic darts (technically does not have to be a dart if fired from space, a simple sphere would be better, wider is better).

      Of course miss and some time in the future you could seriously offend some one way out there somewhere, hell, in a few hundred thousands years you might impact a colony we founded.

      --
      Chaos - everything, everywhere, everywhen
  7. Re:No danger from the asteroids... by aicrules · · Score: 1

    presumably because an alien civilization that can get to our moon would be mostly unphased by us throwing refrigerator-sized satellites at them.

  8. Re:No danger from the asteroids... by roc97007 · · Score: 1

    "Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."

    At worst, they'll have a real use-case when they try the experiment again.

    --
    Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
  9. I'm no math jeanyus, but... by Anonymous Coward · · Score: 1

    Isn't this a fairly straightforward calculation? And given the exact details of this asteroid's spin and other variables aren't the results going to be fairly accurate for just this one asteroid and maybe not extrapolatable to others? I ain't no English jeanus, either.

    1. Re:I'm no math jeanyus, but... by Phil+Karn · · Score: 4, Insightful

      Actually no, it's not a straightforward calculation. That's why they want to conduct the test.

      It's not a simple collision like we learned about in physics class, with the change in the asteroid's momentum coming entirely from the impactor. The impactor will hit at extremely high velocity (by earth standards), meaning that it will carry a lot of kinetic energy (one half mass times velocity squared) in a small volume. This kinetic energy will vaporize and blow off part of the asteroid, which because of the asteroid's small size, will completely escape.

      The mass of the ejecta will greatly exceed the mass of the impactor, so even though it may move much more slowly than the impactor it will carry away considerably more momentum (mass times velocity). The momentum of this ejecta will have most of the effect on the asteroid's trajectory.

      But it's unknown exactly how much momentum will be carried away by the ejecta as this depends on the makeup of the asteroid, its density, porosity, how quickly the impactor stops and releases its energy, etc. So that's why they want to try it.

      A similar effect was at play in the JFK assassination that helped cause the counter-intuitive "back and to the right" motion of his head that had so many people incorrectly thinking there was a second shooter.

    2. Re:I'm no math jeanyus, but... by K.+S.+Kyosuke · · Score: 1

      The mass of the ejecta will greatly exceed the mass of the impactor, so even though it may move much more slowly than the impactor it will carry away considerably more momentum (mass times velocity).

      It will only "carry away the momentum" if you hit it against the direction of its motion. Depending on the hit point, you can nudge it in practically any direction (although some are more favourable from the POV of celestial mechanics and our technological limitations).

      But it's unknown exactly how much momentum will be carried away by the ejecta as this depends on the makeup of the asteroid, its density, porosity, how quickly the impactor stops and releases its energy, etc.

      But you ought to be at least able to consider a perfectly inelastic collision as the minimum for your momentum transfer. Seems like everything else is an (uncertain) bonus.

      --
      Ezekiel 23:20
  10. Re:I predict AEAOR by Oswald+McWeany · · Score: 2

    I predict "an equal and opposite reaction"

    The asteroid will fire a satellite back at us!

    --
    "That's the way to do it" - Punch
  11. Re:No danger from the asteroids... by spikenerd · · Score: 1

    Good point. We should avoid preparing for the future so we can minimize the total number of experiments with potential to go wrong!

  12. You mean... by bferrell · · Score: 1

    Not on accident?

  13. ITT by GrumpySteen · · Score: 1

    People who don't understand that a refrigerator sized satellite won't blow apart or make large changes to the orbit of a 527 billion kg asteroid.

    1. Re:ITT by Shotgun · · Score: 1

      I'm wondering what happens when the fridge hits at 6 time the speed of a bullet. (WTF is that? Why can't they just give a velocity?)
      Will it vaporize? Punch through?

      I'd like to see them harness another, much smaller asteroid, by landing thrusters on it. Then, using it's much larger mass, impact with much lower velocity. Slowly change the orbit of the conglomerate to bring it all into a near Earth orbit and then use it as the beginning of a space station.

      --
      Aah, change is good. -- Rafiki
      Yeah, but it ain't easy. -- Simba
    2. Re:ITT by erapert · · Score: 1

      They're planning on impacting the moon of Didymos-- nicknamed Didymoon-- not Didymos itself.
      At present the mass of Didymoon is unknown, but certainly smaller than 527 billion kg.

    3. Re:ITT by techno-vampire · · Score: 1

      If we can change its velocity by 1 cm/s, after 1 year, its position will have changed by almost 316 K. That may not sound like much, but it would probably be enough to change a grazing impact to a very near miss. And, of course, the faster the projectile, the higher the kinetic energy is and the more effective it is. And if we can't get a higher impact velocity, we can always make the projectile more massive; this won't raise the kinetic energy much, but it will improve the momentum which might be enough.

      --
      Good, inexpensive web hosting
    4. Re:ITT by Khashishi · · Score: 1

      its position will have changed by almost 316 K

      Its position changes by a temperature?

  14. The real story here: by Gravis+Zero · · Score: 1

    NASA Is Going To Crash a Satellite Into an Asteroid on Purpose

    I mean, accidental hypersonic impacts into things is kind of old hat. ;)

    --
    Anons need not reply. Questions end with a question mark.
  15. Funny thought by sumsguy · · Score: 1

    FTA: "Neither pass poses any threat, according to NASA." It would be hilarious if that collision will suddenly change the asteroid's path to collide with Earth.

    1. Re:Funny thought by gtall · · Score: 1

      Only if it lands on your head leaving the rest of us rolling in glee.

  16. Downsides? by Holi · · Score: 1

    Are they the least bit worried that they put an asteroid on an eventual collision course?

    --
    Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
    1. Re:Downsides? by gtall · · Score: 1

      NASA Scientist: Let's deflect an asteroid.

      NASA Supervisor: But what if we deflect it into the Earth, we'd better run some simulations with our supercomputers first.

      NASA Scientist: Bah, humbug. Let's just wing it.

  17. Dear NASA by DivineKnight · · Score: 1

    Dear NASA,

    If you ever wish to remain relevant, you had best put someone (a human), on a celestial body, and quick. The Moon is always an option, as is Mars, Venus, etc. But at the current rate things are going, people are focusing a bit too much on...earthly affairs. They are forgetting that there are other worlds out there, and that they are accessible to us; hence, they begin to care too much about what they have here, in front of them. And as such, they are beginning to feel claustrophobic, even when there is plenty of space, both on Earth and elsewhere.

    1. Re:Dear NASA by angel'o'sphere · · Score: 1

      Venus most certainly is not an option.
      Besides Moon and Mars there are not many options anyway, Titan? Europa?

      --
      Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
  18. Re: CNN doxxing and blackmailing by MightyMartian · · Score: 1

    Has he been shot?

    --
    The world's burning. Moped Jesus spotted on I50. Details at 11.
  19. Re:No danger from the asteroids... by R3d+M3rcury · · Score: 1

    Well, if it works "really well" and that asteroid is knocked into a collision course with Earth, we could always do it again and knock it somewhere else.

    I'm pretty sure that NASA is smart enough to swat it "away" from Earth so that, at the very least, they'd have sufficient time to swat it away again.

  20. Re:Idiotic by cavreader · · Score: 1

    Wow! You best get on the horn to NASA and share your stunning insight because I'm sure nobody involved in the project realizes the danger.

  21. BOINK!... by ZNetracer · · Score: 1

    Am I the only one that was reminded of the satellite crashing into the mother ship at the beginning of Independence Day?

  22. Be careful of the shrapnel by Kernel+Kurtz · · Score: 1

    Just sayin

  23. Starship Troopers by TheStickBoy · · Score: 1

    But its common knowledge that these asteroids are being sent by the Arachnids.
    You know its true, we gotta send our soldiers to Klendathu



    "We thought we were smarter than the Bugs"

  24. Re:Idiotic by Jhon · · Score: 1

    "Wow! You best get on the horn to NASA and share your stunning insight because I'm sure nobody involved in the project realizes the danger.", he said is his best "Frasier Crane" voice.

  25. Deep Impact by Zorro · · Score: 1

    They already did this with a comet. https://www.jpl.nasa.gov/missions/deep-impact/

  26. Re:No danger from the asteroids... by K.+S.+Kyosuke · · Score: 1

    So what happens when the test works really well and suddenly that asteroid is knocked into a collision course with earth?

    Nothing, because it won't happen. Any change of the asteroid's orbit that we're capable of effecting at this point in our technological evolution with non-nuclear means is barely measurable, and even the nuclear option would be negligible.

    --
    Ezekiel 23:20
  27. Re:question is .... by gtall · · Score: 1

    Yeah, yer right. We shouldn't attempt deflection experiments on asteroids because they might go wrong. We should wait until one has our address stamped on its ass and then either be too late to deflect it or have one Hail Mary shot at it.

  28. Re: No danger from the asteroids... by aicrules · · Score: 1

    Yeah it would look something like the shape of his shadow permanently emblazoned on the chunk of street surface that he had been standing on as it floats through space in the orbital path formerly occupied by Earth.

  29. Calling Bruce Willis by gazelam · · Score: 1

    Needed: 1 drilling team willing to crash their spacecraft craft into an asteroid, drill a hole in it, place a nuclear weapon and then kiss their asses goodbye. Send CV and client testimonials to NASA, c/o CraZY Eddie, PO Box 1998, Canaveral, FL

  30. Re: No danger from the asteroids... by K.+S.+Kyosuke · · Score: 1

    Environmentalists are in no position to allow or disallow the use of nukes against anything, governments are.

    --
    Ezekiel 23:20