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."
by Anonymous Coward
on Monday August 31, @06:25PM (#29267971)
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.
I'm very curious to learn which is their business plan. Could it be "pay us a gazillion dollars or we won't use our technology against the asteroid"?
Any technology that can be used to divert an asteroid away from the Earth can also be used to direct one toward the Earth. I would guess they could get venture capital for a business plan like "pay us a gazillion dollars or we will use our technology to alter the course of this asteroid."
Lots of other businesses have "destroy the Earth" in their business plan. Why should commercial space ventures be any different?
by Anonymous Coward
on Monday August 31, @08:00PM (#29268699)
Glad you support the free market!
That sound you hear is people laughing at you, not with you.
When the cost of making this device is equal to or less than the value provided by it, it will be made.
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.
Until then, since at the moment there would be no value provided by the creation of this that would be equal to or greater than the cost of its creation, the value expenditure won't be made.
And if there is something headed our way that will literally destroy the entire world, "free market" and all, then so be it, huh?
When the cost of making this device is equal to or less than the value provided by it, it will be made.
The problem with that theory is time. Free markets are highly reactive, not proactive. It takes a long time for a gravity tractor to significantly affect an asteroid. By the time the free market realizes that a gravity tractor is of value, it may be too late for it to be effective.
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.
Must be a mistake. The Goa'uld already tried that back in 2002... we used a hyperspace generator to jump the rock around Earth. Worked like a charm too, although it was a bit touch-and-go there for a bit. In any event, Apophis is only a false god. A dead false god.
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.
My backgrounds in space mission design, not geology.. pretty sure the cost to benefit ratio is going to show I'm better off working on asteroid deflection while the geologist down the street gets to work looking at mitigating supervolcanoes. And of course the automotive engineers over there on the other side of town are probably best off developing newer, more efficient cars, and my friends in aerodynamics should working on more efficient aircraft and better wind turbines.
by Anonymous Coward
on Monday August 31, @06:36PM (#29268077)
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.
The time required to make this work seems too long to be practical. I would think we'd have a year at most to find an asteroid on a collision course. Furthermore, I think we should concentrate our efforts on finding the rocks that are a threat.
I've always thought it would be best to use some kind of propulsion system to help move the asteroid in it's same direction causing it to overshoot us. Trying to change it's current vector or trajectory seems like it would be wasting energy.
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.
How are they going to know that they need to deploy their "gravity tractor", if NASA's program to inform them is shut down? And are they going to hire Bruce Willis to drive it?
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.
The summary seems to imply a "British Company To Pick Up NASA's Dropped Asteroid Ball" slant. "Seems" is used here because rhetorical device is relied on because the facts themselves don't do the job.
One failure is the false dichotomy created by positioning the Near Earth Object program(s -- there's seven http://neo.jpl.nasa.gov/programs/ [nasa.gov] ) for detecting and tracking thousands of rocks against a vehicle intended to take one such rock and push it around. A tactic like this is common when the writer has little faith in the intended focus of the piece to carry the story alone, and they present a badly constructed straw man in contrast.
The second problem is in presenting NASA's possible future NEO (a currently operating and planned continued project, mind you) budget crunch as problematic, whereas this British company's announcement of what amounts to grand plans on paper that would admittedly require huge national or international funding to even begin is held up as "taking the lead".
If announcing one has plans that one considers viable is "taking the lead", the team in TFA is taking the lead behind dozens of other "programs" in equal or farther planning stages, some described in a recent Discovery/Science Channel program, many written up in popular media over the years and available to the search engine of your choice, with the Top Ten Ways listed at http://dsc.discovery.com/space/top-10/asteroid-stopping-technology/index-03.html [discovery.com] . Harry Stamper's roughnecks and Spurgeon Tanner's shuttle crew are not among them, which didn't stop me from using them in the obligatory/. inclusion of SF references.
Ah yes. As always, the random Slashdot poster is smarter and knows better than whole legions of physicists and engineers.
Actually, he doesn't have to be smarter than legions of physicists and engineers. So far, this is in a very early planning stage. Therefore, changes are he only has to beat a board of executives who knows nothing about physics or science (on average) who have been given a high level executive summary of this great idea that they should invest in and how it can both lead to a better world (not being smashed up by said cosmic nasty) and possibly making a good deal of money based on their investment (after all
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).
The problem is that a number of the objects of interest
may be particulate agglomerations that aren't solid enough to have something push at them,
are likely to be spinning, so that you would first need to stop their spin, otherwise see this [howstuffworks.com]
are likely to be of irregular shape and mass distribution that would make it difficult to push them efficiently in the direction you want without getting unwanted spin resulting.
Sure you could solve each of these problems individually, but a gravity tug bypasses them all at once, at the expense of needing either
more time to operate
a larger attractive mass requiring more energy to move both it and the target object
Probably the cheapest solution would be to refine a good sized nickel-iron asteroid into a compact solid metal mass and then attach a solar sail for thrust. Bonus points for compressing the metal mass into neutronium compressed by a diamond shell.
Erm, actually, an asteroid big enough to knock out a city is about 10m in diameter. We'd probably have no notice whatsoever. Of course the likelihood that it would hit a city is pretty small.
Nuclear weapons would be far more entertaining; kind of a near-Earth fireworks display ("ooooh, aahhhh"). Besides, one more used up there is one less that may be used down here.
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 [johnstonsarchive.net]
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 [daviddarling.info] http://books.google.com/books?id=4S2KocYp8AkC&pg=PA159&lpg=PA159&dq= [google.com]"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
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.
I don't think that humans will go extinct, at least not before the second coming of Jesus Christ to this earth and then not either. We humans of modern times have come to think that we are in charge of this world even though we did not make it. This world will be destroyed by fire some day, but not until God personally does so. (2Peter 3:7) Contrary to what most people think this day and age, we are not the bosses of this world because this is not our world.
We're discussing science in this thread, not mythology.
The Free Market fixes another intractable problem! (Score:5, Funny)
Oh, never mind then.
What about their business plan? (Score:4, Funny)
Parent
Re:What about their business plan? (Score:5, Funny)
Be a shame if something happened to it.
Parent
Re:What about their business plan? (Score:4, Insightful)
I'm very curious to learn which is their business plan. Could it be "pay us a gazillion dollars or we won't use our technology against the asteroid"?
Any technology that can be used to divert an asteroid away from the Earth can also be used to direct one toward the Earth. I would guess they could get venture capital for a business plan like "pay us a gazillion dollars or we will use our technology to alter the course of this asteroid."
Lots of other businesses have "destroy the Earth" in their business plan. Why should commercial space ventures be any different?
Parent
Re: (Score:2)
(like killing Arabs).
Wait...what?
Re:The Free Market fixes another intractable probl (Score:4, Interesting)
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
Parent
Re: (Score:2)
The problem with that theory is time. Free markets are highly reactive, not proactive. It takes a long time for a gravity tractor to significantly affect an asteroid. By the time the free market realizes that a gravity tractor is of value, it may be too late for it to be effective.
The only question is.... (Score:2)
Smart Bomb or Hyperspace?
Re: (Score:2, Funny)
Those technologies don't even exist.
We should get some psychics and move it by telekinesis, duh.
Re: (Score:3, Informative)
Don't worry, the time travelers will give us the technology JUST IN TIME.
First things first. (Score:4, Insightful)
Not necessarily (Score:5, Informative)
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.
Parent
Re:Not necessarily (Score:5, Interesting)
http://en.wikipedia.org/wiki/Year_2038_problem [wikipedia.org]
Parent
Re:Not necessarily (Score:4, Funny)
Sometimes, you need to create a problem to solve another.
Warm regards,
Yahweh
Parent
Re: (Score:2, Informative)
This should scare some people.
I actually don't recommend reading this if you obsess about things.
http://en.wikipedia.org/wiki/Risks_to_civilization,_humans_and_planet_Earth [wikipedia.org]
For the rest - have fun and sweet dreams.
Re:Not necessarily (Score:5, Funny)
Apophis will make a near pass to Earth in 2029.
Must be a mistake. The Goa'uld already tried that back in 2002 ... we used a hyperspace generator to jump the rock around Earth. Worked like a charm too, although it was a bit touch-and-go there for a bit. In any event, Apophis is only a false god. A dead false god.
Parent
Re:First things first. (Score:5, Insightful)
Parent
Re: (Score:2)
Can't we do both at once?
My backgrounds in space mission design, not geology.. pretty sure the cost to benefit ratio is going to show I'm better off working on asteroid deflection while the geologist down the street gets to work looking at mitigating supervolcanoes. And of course the automotive engineers over there on the other side of town are probably best off developing newer, more efficient cars, and my friends in aerodynamics should working on more efficient aircraft and better wind turbines.
Lots of p
What could go wrong. (Score:5, Funny)
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.
15 years to prepare? (Score:2)
I've always thought it would be best to use some kind of propulsion system to help move the asteroid in it's same direction causing it to overshoot us. Trying to change it's current vector or trajectory seems like it would be wasting energy.
Re: (Score:2, Interesting)
Missile Command? (Score:2)
Seems like they could make some kind of game, and have people play that game to control the missiles that shoot down asteroids threatening cities.
(Ok, so that is a combination of Ender's Game and Missile Command)
Asteroids? (Score:2)
Seems like they could make some kind of game, and have people play that game to control the space-ship that shoots asteroids.
http://en.wikipedia.org/wiki/Asteroids_(video_game) [wikipedia.org]
Red lighted (Score:2)
British Company Takes Lead To Stop Asteroids
Thank God! That was such a stupid idea to base a movie on that game [slashdot.org].
Gotta find them first (Score:4, Insightful)
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.
Re:Gotta find them first (Score:5, Informative)
Already on it:
http://en.wikipedia.org/wiki/PAN-STARRS [wikipedia.org]
http://en.wikipedia.org/wiki/Large_Synoptic_Survey_Telescope [wikipedia.org]
Parent
CCTV (Score:5, Funny)
Re: (Score:2)
Does this plan involve taking all of Britain's CCTV cameras and pointing them towards the sky?
Yes indeed it does, thereby making one giant CCD imager.
Re:CCTV (Score:5, Funny)
Parent
I have a few questions... (Score:2)
Re: (Score:2)
And are they going to hire Bruce Willis to drive it?
No, Robert Duvall [wikipedia.org].
One stone, two birds... (Score:3, Interesting)
Here's an idea...
How many tons of launch debris do we dodge daily in orbit?
Why not collect it, and use its condensed and combined mass for such a "gravity tractor?"
Just asking...
Re:One stone, two birds... (Score:5, Interesting)
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.
Parent
Rosoideae Rosa By Alternative Nomenclature (Score:4, Insightful)
The summary seems to imply a "British Company To Pick Up NASA's Dropped Asteroid Ball" slant. "Seems" is used here because rhetorical device is relied on because the facts themselves don't do the job.
One failure is the false dichotomy created by positioning the Near Earth Object program(s -- there's seven http://neo.jpl.nasa.gov/programs/ [nasa.gov] ) for detecting and tracking thousands of rocks against a vehicle intended to take one such rock and push it around. A tactic like this is common when the writer has little faith in the intended focus of the piece to carry the story alone, and they present a badly constructed straw man in contrast.
The second problem is in presenting NASA's possible future NEO (a currently operating and planned continued project, mind you) budget crunch as problematic, whereas this British company's announcement of what amounts to grand plans on paper that would admittedly require huge national or international funding to even begin is held up as "taking the lead".
If announcing one has plans that one considers viable is "taking the lead", the team in TFA is taking the lead behind dozens of other "programs" in equal or farther planning stages, some described in a recent Discovery/Science Channel program, many written up in popular media over the years and available to the search engine of your choice, with the Top Ten Ways listed at http://dsc.discovery.com/space/top-10/asteroid-stopping-technology/index-03.html [discovery.com] . Harry Stamper's roughnecks and Spurgeon Tanner's shuttle crew are not among them, which didn't stop me from using them in the obligatory /. inclusion of SF references.
Re: (Score:2)
Ah yes. As always, the random Slashdot poster is smarter and knows better than whole legions of physicists and engineers.
Re: (Score:2)
Ah yes. As always, the random Slashdot poster is smarter and knows better than whole legions of physicists and engineers.
Actually, he doesn't have to be smarter than legions of physicists and engineers. So far, this is in a very early planning stage. Therefore, changes are he only has to beat a board of executives who knows nothing about physics or science (on average) who have been given a high level executive summary of this great idea that they should invest in and how it can both lead to a better world (not being smashed up by said cosmic nasty) and possibly making a good deal of money based on their investment (after all
Re:Bad science (Score:5, Informative)
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).
Parent
Re:Bad science (Score:4, Informative)
Sure you could solve each of these problems individually, but a gravity tug bypasses them all at once, at the expense of needing either
Probably the cheapest solution would be to refine a good sized nickel-iron asteroid into a compact solid metal mass and then attach a solar sail for thrust. Bonus points for compressing the metal mass into neutronium compressed by a diamond shell.
Parent
Re: (Score:2, Informative)
Works perfectly fine if you have enough lead time
We should be happy enough when we see it coming at all.. How much "lead time" do you expect to have?
Re: (Score:3, Informative)
Re: (Score:3, Insightful)
Nuclear weapons would be far more entertaining; kind of a near-Earth fireworks display ("ooooh, aahhhh"). Besides, one more used up there is one less that may be used down here.
Re:Bad science (Score:5, Interesting)
Parent
Re:Bad science (Score:4, Insightful)
Holy crap, decimate used with the original definition.
OK, now I've seen everything.
Parent
Re: (Score:2)
I'm not worried about radiation exposure from this sample. The odds of one of those atoms decaying is infinitesimal!
Re:Bad science (Score:5, Insightful)
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.
Parent
Re: (Score:3, Funny)
Re: (Score:3, Insightful)
...If humans do go extinct,...
I don't think that humans will go extinct, at least not before the second coming of Jesus Christ to this earth and then not either. We humans of modern times have come to think that we are in charge of this world even though we did not make it. This world will be destroyed by fire some day, but not until God personally does so. (2Peter 3:7) Contrary to what most people think this day and age, we are not the bosses of this world because this is not our world.
We're discussing science in this thread, not mythology.
Re: (Score:3, Funny)
All of them? I don't recall seeing a seven headed dragon anywhere.
Re: (Score:2, Insightful)
now how are we gonna get a gazillion tons of water all the way to the asteroid?
Re: (Score:2)
Won't matter much if we can divert an asteroid if budget cuts cost us the ability to see it coming.
Deep down, nobody really believes it will ever happen, especially Congress, which has no awareness of consequence anyway.