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Engineers Working On Swarm Of Laser Wielding Satellites To Deflect Asteroids
Zothecula writes with news involving space and lasers. From the article: "A collision between Earth and an asteroid a few kilometers in diameter would release as much energy as the simultaneous detonation of several million nuclear bombs, and with the impact of an asteroid estimated at around 10 km (6.2 miles) in diameter believed to be responsible for wiping out the dinosaurs, numerous strategies have been devised to try and avoid such devastation. The latest idea comes from engineers at Glasgow's University of Strathclyde who suggest that a swarm of laser-wielding satellites could nudge Earth-bound asteroids off their collision course."
Sharks in space?
...we could attach sharks to the satellites...
Which means more space junk. Whee!
A feeling of having made the same mistake before: Deja Foobar
Are those friggin' satellites with friggin' lasers on their friggin...Yeah, I don't know where I was going with that.
So when asteroid come to hit us we can split them in two and then two can hit us! how practical
"These satellites, which we will use for asteroid deflection only, not for covert assassinations or as a dreadful weapon of war, will be a vital part in ensuring the future of human civilization" said a Pentagon spokesperson. "We look forward for a chance to put these satellites, which will not be a part of any secret missile shield program nor used to destroy terrorist hideouts, into orbit to protect our planet."
What political party do you join when you don't like Bible-thumpers *or* hippies?
Like the dozens of similar comments waiting to suggest that this technology could be used to target land-based settlements (although if you RTFA, it's suggested that it might not be able to) or other satellites, there will probably be a number of concerned politicians who will gun this down on the same premises. With all of the cyberwar going on these days, both intergovernmental and rogue, it seems inevitable that someone will figure out how to hijack these things. (Possibly Kevin Mitnick whistling into a payphone with a wad of chewing gum and a wrapper.)
And hence the first rule of world-changing mad science: don't make the world's largest bomb if you have to count on others to use it for deterrence.
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I stopped reading at "Swarm of Laser Wielding..." when an image popped into my mind:
A big bad asteroid hurtling towards our little blue planet. Then the camera pans around and we see a huge number of little dots. Flying closer, we see a huge swarm of frickin' space sharks swooping down towards the asteroid, shooting their lasers at it while Bruce Willis, riding the lead shark, yells "Yippee-ki-yay, motherfucker." I'd pay money to see that.
The Angels have the Phone Box
I don't know why they're looking at lasers, but the only idea I've heard, which sounds workable, is send up robotic rockets which attach, drive in a spike or something, and drive the thing to a new course.
Why lasers? Do you really trust them not to ever be directed earthbound, towards some guy who has a name which rhymes with Sim Pong Nun? So very tempting and all you need is a rationalizer-in-chief to make it so.
A feeling of having made the same mistake before: Deja Foobar
yep ... what could possibly go wrong?
Why satellites and not frickin' sharks?
"These satellites, which we will use for asteroid deflection only, not for covert assassinations or as a dreadful weapon of war, will be a vital part in ensuring the future of human civilization" said a Pentagon spokesperson. "We look forward for a chance to put these satellites, which will not be a part of any secret missile shield program nor used to destroy terrorist hideouts, into orbit to protect our planet."
Meanwhile, at the UN "We other, lesser governments, know that the US is only interested in protecting ALL of us (the little people) from comets and such and not just interested in militarizing space because they just couldn't....they wouldn't." "They'd never blow anybody up with these" added Iraq.
Lasers are just a way to transfer energy and the only energy those satellites will have comes from a few solar panels. It would be too weak to pose a threat to even a single human. It could theoretically be used for targeting though.
as i remember it did not go so well hint if they look like pyramids they are a NO GO
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It wasn't even a good movie when they did it with missiles.
Have gnu, will travel.
If you look at the details, which would include the mass and velocity of the asteroid in question, you'll understand. The mass and fuel needed for such a "tug" satellite would be directly proportional and not possibly to launch, much less have extra fuel to maneuver over to the target, etc.
They asteroids in question only look small and slow because of the incomprehensible size and emptiness of the background. That is, lack of a good reference point.
http://www.brighthub.com/science/space/articles/64710.aspx
Learning HOW to think is more important than learning WHAT to think.
We can't identify all potential large asteroids and astrophysicists have estimated those % and they are, as I recall, 10-20% of those in the Kuiper Belt.
Even with the best defensive satellites, we may not detect a big asteroid in time to deflect it. Some significant asteroids approach from the direction of the Sun making them hard to detect.
When the diameter of an asteroid gets twice as large, it takes 8 times the energy to alter its course a given amount and certainly has probably more than 8 times the impact damage.
The amount of energy needed to accomplish the task in a short amount of months seems unrealistic to me, but I admit I am not a physicist. If you have ten passes (near misses) to alter its course maybe you can win. Unfortunately, every time an asteroid comes close to Earth, its orbit changes a bit and who knows it doesn't get closer to some other object away from the earth that then swings the orbit dead on (pardon the expression) to earth, such that your early slight movements were counteracted.
It is certainly iffy. I want to go on a vacation now.
Hm, how about practice on space junk now in orbit around earth? Less distance means you need less precise aim, and you start making a dent in all the junk in orbit. In addition you don't have to wait until there is something in range to practice.
But it doesn't matter whether we use a gravity tug, a physically attached rocket tug, lasers or any other technology. At the end of the day the energy requirements are the same. We have to apply a considerable amount of force over a considerable amount of time. Even if we could come up with a long enough extension cord to plug satellite based lasers into the wall, the electric bill would be enormous. Incidentally, what's the energy efficiency on your average high-power laser? Also, how much of that energy ends up as delta-v when the lasers paint yon incoming asteroid?
At least a gravity tug doesn't require a constant input of energy to function - but even a gravity tug will end up costing the same amount of energy to do the same amount of work. Physics is a bitch - if we need a 3% delta-v on a billion-ton object, we need to pony up x amount of energy to do it.
...I deplore these aggressive measures. The better answer is to move the Earth out of the asteroid's way.
It's a power so great it can only be used for good or evil!
Where are the Spaceballs when we need them? Mega-maid will handle this!
We should just accept our fate. Why meddle in God's work? If the planet is wiped out by an asteroid, let us embrace our destiny instead of trying to change it. Our deity knows what is best for us.
Exactly how many gigatons is "several million nuclear bombs"?
I mean, obviously it's largely irrelevant at the scales they're talking about and the layperson reads that as "several million times the hiroshima bomb" which is what they're going for. But can we stop dumbing down this shit and actually try to educate people just a little?
I believe the supposition is that the lasers could act over a long time and at very long ranges when compared to kinetic methods which would have to wait until the thing got close before acting. The earlier you start pushing on the object the less you have to push in order to change its course sufficiently. As far as supplying power, in addition to solar and onboard reactors there is also the possibility of beaming energy from the ground. It would be inefficient, but then you just send way more energy than is needed at the other end.
... have the LHC generate a black hole, and time it so the black hole intercepts the asteroid and eats it?
It would be too weak to pose a threat to even a single human.
Careful with the hyperbole there. A couple 10s of watts is enough to pose a threat to a human (as in "burns-a-hole-through-you" threat).
50mw is enough if you count "blindness" as a threat.
Wrong! the solar cells don't have to be itty bitty things if they are out of the atmosphere.
Or, "How I Learned To Stop Worrying And Learned To Love Massive Asteroid Impacts That Wipe Out All Surface Life"
We are talking about a 400 lb payload. Compare that with the 1800 lb of a voyager probe.
This would make an awesome addition to our laser guided munition platforms. Most of the risk involved in operating those platforms is having to lase the target.
If we dual-purpose this project (atmospheric defense and orbital target marking) we could definitely get the money from our bloated defense budget to pay for it. After all, that is how we funded the space program during the 60s (the only time we actually made any real progress in space).
This sounds like an idea I had recently.
I wonder if the spacecraft actually have to get close to the asteroid for this to work. I mean, once you're in orbit, you're more than half way to anywhere you want to go, but I still wonder if a system like this wouldn't be more responsive and easier to maintain if we kept it in earth orbit? Do we have lasers that won't diverge more than a meter over a few gigameters of distance?
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I played this game years ago. http://en.wikipedia.org/wiki/Asteroids_(video_game)
..a single laser mounted triangular ship that spins and thrusts on a 2d plane
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Lasers are more efficient because they use bits of the asteroid itself as reaction mass.
This idea is to use lots of little lasers instead of one big one. The big one could theoretically be directed Earthward, maybe, but the little ones almost certainly can't. They're too small to have much effect through the atmosphere.
If some military with launch capabilities wants to put lasers in orbit, you won't even know about it. Why would they advertise it by calling it an asteroid shield?
"At the end of the day the energy requirements are the same."
No.
Conventional rocket: you have to haul up the fuel and the reaction mass. Also very inefficient
Ion thruster: very efficient, can be solar powered, but you still have to haul up the reaction mass
Lasers: probably more efficient than a conventional rocket, can be solar powered, don't need reaction mass (they use the asteroid for that)
The amount of stuff you have to haul up to the asteroid is GREATLY reduced using the laser solution, and therefore the total required energy is much less.
Its for... asteroids where asteroid means: hostile target.
This sig is not paradoxical or ironic.
gas's can be use to make laers of HIGH power these could be use to power the lasers and soler used for the computers to guide the lasers
If these swarms could be used to nudge asteroids so that they don't hit Earth, they could also be used to nudge asteroids so that they do hit Earth.
Any such project will have unprecedented offensive capability.
I have this capacitor bank that's been charged for a few weeks by some modest solar panels and this whole setup powers this free electron laser I've been working on. If you think it's too weak to be a threat, then I hope you wouldn't mind stepping in front of it during the next planned demonstration for the black budget comittee.
Would that still apply if the source of the laser is out of the atmosphere and the human in question is within the atmosphere, quite a distance away?
an autonomous network of satellites orbiting earth safely out of reach, with lasers powerful enough to deflect a huge asteroid - what could possibly go wrong?
If some military with launch capabilities wants to put lasers in orbit, you won't even know about it. Why would they advertise it by calling it an asteroid shield?
You advertise it so you can put a bigger laser in orbit; since this is a popular threat scenario you can probably militarize the hell out of space before people wake up to object. But then again, maybe I'm a cynic.
all about time. IF you had enough time, you could just launch rocks and have a robot pt them on the asteroid. the increase in mass will changes it's course.
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The proposal is to put smaller lasers up.
The proposal is to put smaller lasers up.
Meh, really?
day of the triffids
The article: the details it has.
"These satellites, which we will use for asteroid deflection only, not for covert assassinations or as a dreadful weapon of war, will be a vital part in ensuring the future of human civilization" said a Pentagon spokesperson. "We look forward for a chance to put these satellites, which will not be a part of any secret missile shield program nor used to destroy terrorist hideouts, into orbit to protect our planet."
With all of the computer network breakins in the past couple of years, what's to stop the same thing from happening here?
We can't even tell if an asteroid will hit Earth or not with reasonable precision, we can only calculate a chance. Controlling or even telling where will it hit Earth is impossible, which means anyone who tries this has a fair chance of directing the asteroid on themselves.
I'm pretty sure the same thing that keeps that from working is the same thing that keeps us from getting cooked by the sun.
Why go to the bother of lofting power supplies and creating lasers when there is a nonstop source of radiant energy at the center of our solar system?
Just create a bunch of mirrors and point them all at the same spot on the side of the asteroid, create the big gas plume, and send it on its way.
Context, it doesn't really mean anything to you then.
It's much more likely they would be used to disable or destroy other spy or communications/command & control satellites than to deflect an asteroid...
wouldn't it be more efficient to have the lasers ground based and just give them extra juice to overcome any losses in the atmosphere? Seems like it would be a lot cheaper and avoid that "militarization of space" problem.
if they are too big then they run the risk of being damaged by debris.
I wouldn't entirely put that past the Americans though.
Hard to maintain focus through the atmosphere. You could focus well enough to hit a collection array in LEO but probably not well enough to vaporize rock at distances measured in AU. It also occurs to me that the charging beam could be constant while the ablation beam could be pulsed for energy density.