Part of me gets that you can't "kill" an asteroid, and that a giant rock moving towards the earth would just be turned into many smaller rocks moving towards the earth... but that said, I think this sort of thing still might be useful, and I'd love someone to explain to me otherwise.
First, small rocks more easily burn up on their way down. So smashing a big rock to pieces increases the surface area enough that maybe that can make it safer for humans.
Secondly, perhaps the energy hitting the big rock would 'deflect' it ever so slightly. Fire it early enough, and you can make it completely miss the earth.
As a deflector (launched years or decades from impact), you can nudge the impactor out of its present orbit by gently ablating one side from a distance; You can do this iteratively until the impactor's orbit changes enough to miss Earth.
Decades is sufficient for some of the continuous-thrust alternatives, though, depending on scale.
As a point defence weapon (launched weeks or months from impact), you can send the nuke in as close as possible and detonate in order to break up the body. Yes, this would cause lots of smaller impactors, but over some size ranges it's preferable because ablation is insufficient. If 99% of the smaller impactors miss Earth, we win... in some cases.
Just breaking up a large impactor (at the very last minute, launched minutes or hours before impact) doesn't help so much if everything still hits Earth, because a planet-killer turns into hundreds of city-killers randomly spread out.
On the other hand, a small impactor could be dramatically affected by a nuke, with plausible amounts of vaporization going on. There's quite a lot of risk surface in small impactors, and they would be hard to spot until very close.
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Bong Wie is working through a NIAC grant on the problem:
One interim observation: a nuke which detaches from a small cratering round which hits first, digging a hole for the nuke to fit in, would multiply its effectiveness severalfold.
It's a very different problem in each different size class of impactor (as well as orbital classes). 10m, 100m, 1000m, 10000m are all of concern in unique ways; each order of magnitude increase in diameter raises mass by three orders of magnitude.
Impact energy would rise with the cube of the diameter, I guess. So splitting up one large asteroid into a swarm of smaller ones is desirable. With any luck, some of the debris would even miss.
The bigger problem is that that kind of missile system can be easily weaponized (China and the US have successfully tested satellite killers and the USSR maybe too), so simply enhancing ICBMs for that without international oversight is problematic.
The United States continues to invest billions of dollars in advancing nuclear weapons science (NIF,ASCI,LEP). A critical detonation of a weapon is unnecessary. There is plenty of useful data available from a long-term program such as NIF, which DOE uses to refine physical simulations of weapons phenomena.
If USSR would get capability to kill GPS satellites, U.S. nuclear subs could not target their missiles anymore. The rest of U.S. nuclear arsenal is in B2 bombers in known airfields and ICBM's in known silos. So by using their ICBM's to knock off airfields and silos, USSR could theoretically kill U.S. nuclear cabability withouht being hit.
This is potentially a powerful statement for Russia, though the article doesn't make it clear if the weapons are designed to break up the asteroid or redirect it. If the latter, it's extremely threatening: if you have the capability to deflect an asteroid to miss the earth, you can just as easily deflect one to hit.
The article describes the asteroid Apophis as coming dangerously close but doesn't mention that it's not deemed a threat anymore.
It's good PR for Russia's military power though if it could be done.
[+] [-] mabbo|10 years ago|reply
First, small rocks more easily burn up on their way down. So smashing a big rock to pieces increases the surface area enough that maybe that can make it safer for humans.
Secondly, perhaps the energy hitting the big rock would 'deflect' it ever so slightly. Fire it early enough, and you can make it completely miss the earth.
Thoughts?
[+] [-] mapt|10 years ago|reply
As a deflector (launched years or decades from impact), you can nudge the impactor out of its present orbit by gently ablating one side from a distance; You can do this iteratively until the impactor's orbit changes enough to miss Earth.
Decades is sufficient for some of the continuous-thrust alternatives, though, depending on scale.
As a point defence weapon (launched weeks or months from impact), you can send the nuke in as close as possible and detonate in order to break up the body. Yes, this would cause lots of smaller impactors, but over some size ranges it's preferable because ablation is insufficient. If 99% of the smaller impactors miss Earth, we win... in some cases.
Just breaking up a large impactor (at the very last minute, launched minutes or hours before impact) doesn't help so much if everything still hits Earth, because a planet-killer turns into hundreds of city-killers randomly spread out.
On the other hand, a small impactor could be dramatically affected by a nuke, with plausible amounts of vaporization going on. There's quite a lot of risk surface in small impactors, and they would be hard to spot until very close.
---
Bong Wie is working through a NIAC grant on the problem:
http://www.spacesafetymagazine.com/space-hazards/asteroid-hi...
One interim observation: a nuke which detaches from a small cratering round which hits first, digging a hole for the nuke to fit in, would multiply its effectiveness severalfold.
It's a very different problem in each different size class of impactor (as well as orbital classes). 10m, 100m, 1000m, 10000m are all of concern in unique ways; each order of magnitude increase in diameter raises mass by three orders of magnitude.
[+] [-] iSnow|10 years ago|reply
The bigger problem is that that kind of missile system can be easily weaponized (China and the US have successfully tested satellite killers and the USSR maybe too), so simply enhancing ICBMs for that without international oversight is problematic.
[+] [-] workitout|10 years ago|reply
Deflection sounds like a great idea, hit it right and send it off to a safer orbit.
[+] [-] cm2187|10 years ago|reply
[+] [-] DominikR|10 years ago|reply
I doubt that Russia or the US needs to really test nuclear weapons at this point, it is all about the delivery mechanism.
[+] [-] cocoablazing|10 years ago|reply
[+] [-] jgreen10|10 years ago|reply
[+] [-] mattybrennan|10 years ago|reply
[+] [-] ck2|10 years ago|reply
https://www.baycitizen.org/news/japan-disaster/radioactive-r...
http://www.nytimes.com/1997/08/13/us/in-idaho-anger-over-195...
[+] [-] dschiptsov|10 years ago|reply
[+] [-] vlehto|10 years ago|reply
This would mean that "pre-emptive" strike is suddenly lot sweeter deal for U.S. Alternatively restart midgetman program. Yay, more nukes. https://en.wikipedia.org/wiki/MGM-134_Midgetman
This would be "destabilizing" technology. I hope it goes nowhere.
[+] [-] scrumper|10 years ago|reply
[+] [-] fsiefken|10 years ago|reply
[+] [-] ethbro|10 years ago|reply
[+] [-] stephenr|10 years ago|reply
Same applies for phones/tablets/watches, next time you want to write an article about a Samsung device.
[+] [-] dangerpowpow|10 years ago|reply
[+] [-] ascotan|10 years ago|reply
[+] [-] dkarapetyan|10 years ago|reply
Russian scientist (rs): I guess. I mean against international law anyway so we couldn't use them even if we wanted to.
rmc: Can we come up with an excuse.
rs: I guess we could say they're good against asteroids.
rmc: Great, do it!