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British Company Takes Lead To Stop Asteroids
An anonymous reader writes to tell us that following the news of NASA's budget cuts impacting their ability to do things like watch the sky for asteroids, a British company has decided to create a "gravity tractor" ship that could divert asteroids away from Earth if the need should arise. Of course, a gravity tractor certainly isn't a new idea. "Dr. Cordey said the company had worked with a number of space authorities on other methods of protecting the Earth from asteroids, but this one would be able to target a wider range. He said: 'We have done quite a lot of design work on this with the European Space Agency and we believe this would work just as well on a big solid iron asteroid as well as other types.' But the high cost implications mean that before the device could be made, it would have to be commissioned by a government or a group of governments working together."
Oh, never mind then.
Competition, not coordination, in attempting to stop asteroids from ending all life on Earth. What could go wrong...
Meanwhile, in an East Texas courtroom...
Dr. Cordey: Your honor, I'd like to file an injunction to prevent NASA from using their gravity tractor to stop the asteroid that will impact Earth next week.
NASA: This patent is ridiculous. They don't have their own working gravity tractor. They aren't even trying to build one. All of their ideas in their patent come from working with NASA and the ESA.
Dr. Cordey: We don't have our own gravity tractor, but we are working with the ESA to build one. It should be done in a year or two.
NASA: Everyone on the planet will be killed next week. We have to be permitted to stop the asteroid.
Judge: I'm going to allow the injunction. You can appeal it within 60 days if you like. Without patents protection, all we have is chaos. We can't make an exception here just because it suits us.
1 week later: BOOOOOOOOM.
99942 Apophis will make a near pass to Earth in 2029. However, if it passes within a narrow window, called the keyhole, the Earth's (and Moon's) gravity will deflect it such as to place it on a direct Earth impact in 2036. Now this isn't all that likely to happen, but it is possible. Worth having some contingency plans for at least.
All this relies on finding said asteroid years if not decades out.
I can't confirm, but I remember hearing that between NASA and all the other space agencies we track less than 20% of space inside of Jupiter's orbit. A large dark asteroid out of the Kuiper Belt could be closing on us right now and we wouldn't see it until months before impact, too late to do anything about it.
IMHO, lets work on finding and tracking large asteroids first.
Does this plan involve taking all of Britain's CCTV cameras and pointing them towards the sky?
Sure, but at least we have some idea what to do about an asteroid impact. How would we prepare for a supervolcano? The only way to survive is by being somewhere else when it erupts.
That sound you hear is people laughing at you, not with you.
Except that when the "product" is the collective safety of the entire earth and there is no opportunity for profit, then the free market will let it slide, waiting for "big bad government" to fill in the gaps, as it always does, no thanks to the randites.
And if there is something headed our way that will literally destroy the entire world, "free market" and all, then so be it, huh?
FTFY
Nice planet you've got here.....
Be a shame if something happened to it.
I'm curious what it being weaker than the weak and strong nuclear forces and the electromagnetic forces has to do with it. If the design works, it works. I'm curious to see your equations if you think it won't work. Also gravity is the only purely attractive force, and the one thats hardest to explain, which is why we really pay attention to it.
The advantage of a gravity tractor is that you don't have to land, because landing is a *VERY* hard problem on an asteroid. The biggest problem is that its very difficult to latch on, since you can't rely on gravity to hold you in place. Since you don't hae a good idea of the surface before you arrive, its rather difficult to design a solution thats going to work for all the different possibilities.
This leads one to consider how can you manage to deflect an asteroid without landing, and a gravity tractor is an obvious elegant solution. Note also that in this case you're still using the vaunted ion thrusters to impart the force on the asteroid. Considering the spacecraft and asteroid as two separate systems you have to use the thrust to maintain your standoff distance; considering them as one system (my preferred analysis), you have the thrusters moving the whole system, with internal gravity keeping the whole thing together. The only difference between it and landing, as far as thrust is concerned, is that you are limited to a maximum thrust by the gravity bond: the same sized ion thruster on a landed spacecraft and on a gravity tractor will have exactly the same effect.
The only time it would make sense to land is if you wanted to do a very high-thrust chemical burn (or maybe something like VASMIR, which would only be in the emergency case. Of course, in that case, the costs become irrelevant ($50B for a mission or wiping out Europe isn't a hard decision to make) and you're more likely to seek to impart a maximum impulse by doing a high-risk/high-reward method such as a kinetic impactor or nuke (and multiples as backup).
Fuel. The debris occupies a huge volume, and to collect each piece, you have to spend enough time in an intersecting orbit for the piece to come to you.
Nerd rage is the funniest rage.
I think the whole "search for killer asteroids" is fatally flawed. Let's see... the last one hit 200,000,000 years ago. The last time someone won my State lottery was just last week, and typically they hand-out ten of these multi-million dollars prizes a year, so 10 out of 4 million tickets sold.
I have about 500 times better odds of winning my State lottery, than getting killed by an asteroid.
You have a problem with your math and your numbers. Big asteroids hit about every 68 million years. If one hit tomorrow it would kill 6.8 billion people. So on average, we can expect asteroids to kill about 100 people per year. That means you are about 10 times more likely to be killed in an asteroid impact than to win the state lottery.
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If you explode a nuke outside the Van Allens, the fallout is swept away by solar wind. We've done it before. http://www.johnstonsarchive.net/nuclear/hane.html However, a conventional nuke might only decimate an incoming Big Rock, leaving 90% behind. I'd rather see a pusher plate mated to the Big Rock, then detonate specially designed nukes against the plate, like in the Project Orion ship in FOOTFALL. http://www.daviddarling.info/encyclopedia/O/OrionProj.html http://books.google.com/books?id=4S2KocYp8AkC&pg=PA159&lpg=PA159&dq="pusher+plate"+Orion&source=bl&ots=yRM2KRDRst&sig=NWZvu3gbjAAwyKva2-Jl_jlduhM&hl=en&ei=qnucSs-xCJSwsgPxwNCaDg&sa=X&oi=book_result&ct=result&resnum=4#v=onepage&q=%22pusher%20plate%22%20Orion&f=false
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