Will you STOP using this wildly inaccurate description of the actual proposal !
A new international consortium has been set up to figure out what Earthlings could do if an asteroid came hurtling towards the planet on a path of imminent destruction. The project will look at three methods of averting disaster: the Hollywood-sanctioned solutions of sending up a crack team of deep drillers with a nuclear bomb …
"daringly innovative; on the cutting edge. "
Your point is ?
And I have been on this site for a number of years. And there does seem to be a tendency for posters to get their facts wrong - often wildly so.
Recently someone claimed that the NEO was 6 miles in diameter where most info sources were saying ~11m or bus sized
and it's a complete waste of money.* Anything that small will pretty much burn up on entry into the Earth's atmosphere, assuming it doesn't bounce off because it came in at the wrong angle. It's only the ones that would require a nuke that you need to worry about.
*Although I suppose from the politician's point of view that makes it even better, because nothing bad happens from failure, and when if the project keeps failing, you can keep asking for more money. ... Maybe that's why they included the Star Trek style tractor beam too.
Don't know what you read but the report(PDF) calls it a 'gravity tractor' approach. That does NOT mean tractor beam (scifi) it just means flying near it and slowly adjusting it's trajectory by using the tiny gravitational attraction between it and the 'tractor' to provide the virtual 'grappling iron' . As the report suggests this approach will need years to have an effect.
Has nobody thought of playing billiards with NEOs? Could we not build some nice big billiard balls on the moon (Newt will help you there) and fire them at any threatening NEOs using a giant cue?
Put the right spin on it and you could probably get two at once.
In all seriousness I think these people are playing up the threat from NEOs just a tad to try to improve their funding.
"Oh, I've heard of worse," said Ford, "I read of one planet off in the seventh dimension that got used as a ball in a game of intergalactic bar billiards. Got potted straight into a black hole. Killed ten billion people."
"That's mad," said Mella.
"Yes, only scored thirty points too."
The Restaurant at the End of the Universe - Douglas Adams
Soft land on the object with your tail in the 'air' and start pushing.
Rockets are good for lots of sudden thrust, but painful to send all the fuel needed - ion drive is vice-versa.
This approach would be suitable for most kinds of problematic asteroids as long as you can do a sufficiently soft landing.
It gives more control as well I would have thought, unless the object is rotating of course .. hmm I might have to think about that some more I suppose...
A thruster approach is the preferred approach to a NEO confirmed to be on collision course with a number of years notice (probably about five or so). Not only would it take time for the thruster kit to intercept the NEO, it would also need enough time for the slow, gentle push approach to have the desired effect.
The solutions being proposed here are probably for near-emergency situations (say, a doomsday comet gets confirmed with only a year's notice or less--think the 2012 predictions).
PS. To El Reg, the proper term (in the Trek universe) for a force beam intended to push something away from you is a REPULSOR beam. At least one other universe I've read has used the term "pressor beam" for the same thing, but the idea is you don't want to attract the object but repel it away.
But I suspect that they are talking about parking a massive object (ie one that has sufficient mass to do the job) near to the NEO and let the gravitational attraction between the two objects pull the NEO away - or towards the sun I suppose, as long as it's going to miss our blue marble.
"That is indeed what is being proposed although the object would have active propulsion to slowly 'tow' the NEO away from a collision course"
That sounds like a *really* big lump of matter, given the force of gravity. It seems pretty hard to believe moving something that big would easier than moving the NEO itself.
It does sound fanciful doesn't it ?. Nevertheless that is exactly what is being proposed in the document referenced in the article under the title "Gravity Tractor"
"..minimize fuel consumption and maximize the asteroid’s deflection? What are the trade-offs between the mass of the tractor, the distance between the tractor and the NEO, the control laws, and the time required to produce the required deflection? Reliability is a crucial issue given the long periods (several years to a decade) typically required for gravity traction to produce the required deflection. What are the requirements for autonomous spacecraft control procedures to manage hovering station keeping and maintain stability of the traction system over a long period of time in the (verynearby) presence of an irregular rotating mass?"
the issue is that the NEO may not be easy to 'get a hold of'. it may be a loose collection of rubble, for example, or spinning wildly.
in that case your large 'gravitational attractor' (read: huge lump of moon rock with rockets attached) is already under your control - you 'just' park it near to the NEO you want to influence.
the Enterprise was using a tractor beam in an attempt to pull the asteroid out of the path of the planet. But it failed to suitably change the course of the object and they need the deus-ex-machina repulsor beam on the planet to save the day. Never understood why they didn't use the photon torpedoes myself. Split it up into little bits, move the dangerous chunks out of the way, and don't worry about the rest.
"The first problem here will be to stop everyone freaking out when someone fires off a nuke by making sure nuclear response is internationally coordinated."
I would imagine it's quite easy to distinguish between a missile aimed at Moscow/Washington and a rocket equipped to reach escape velocity and enter, at the very least, Earth orbit, before a second stage takes it into outer space.
We are not talking about shooting down an asteroid as it enters the atmosphere over the Pacific. By that point it's game over, far too late,
Eventually it is, but not shortly after its being launched. Because in the first stages the rocket will go up, no matter where its destination lies. If the target is on earth it will eventually change its course and fly in the right direction.
However; most countries would already be on full alert even before the rocket has changed its course. Because the quicker you can intercept such a missile the better. And that's not even mentioning retaliation.
I would think that its vital that they hang around to see where the target is. It's hardly a trivial detail
Otherwise the day Pakistan nukes India, the US will nuke Pakistan, on the assumption it was for them, at which point Russia will nuke the US, on the same basis, and China will nuke Russia, who'll be nuked by Britain, who'll be nuked by France, who'll be nuked by North Korea, who'll be nuked by South Korea, just on reflex.
Kind of like a western bar fight where no-one cares whose swinging at who, everyone just joins in.
quite similar. They'd be launched from the same facilities and are space vehicles not merely rockets flying through the atmosphere. I'm not sure how much extra boos they'd need to break orbit. Initially I was thinking you'd need something Saturn V like, but the exploration satellites don't need launchers like that, so nukes wouldn't either.
On the other hand, if you are talking about a year or more before impact with Earth, there's plenty of time to arrange the nuke launch and clear it with everyone.
I think it's simpler than that, you know. Getting something to an asteroid by definition needs something that can get out of the gravity well, which again by definition means a much bigger rocket than anything in the nuke arsenal. (As you say, if it gets close enough that a regular ICBM could hit it, then we're screwed.) So the easy way to tell if it's a nuke destined for an asteroid is bcos it's sat on top of a sodding great multistage rocket at Baikonur...
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