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Chinese Want To Capture an Asteroid
geekmansworld writes "The Chinese want to capture an asteroid into earth's orbit and mine it. From the article: 'At first glance, nudging an asteroid closer to Earth seems like one of those "what could possible go wrong" scenarios that we generally try and avoid, and for good reason: large asteroid impacts are bad times. The Chinese, though, seem fairly optimistic that they could tweak the orbit of a near-Earth asteroid by just enough (a change in velocity of only about 1,300 feet-per-second or so) to get it to temporarily enter Earth orbit at about twice the distance as the Moon.'"
It's a research paper. It's 2 guys looking at the possibility for the sake of their course grade/diploma. It doesn't mean there's a plan, or a will, or even a wish. Come on editors, click through your links and understand your articles before approving crappy summaries.
your thin skin doesn't make me a troll
I guess slashdot is running out of nerds who post anymore. I don't post much or read many comments here anymore, but when I saw the direction this was heading, I had to log in for the first time in ages.
The first few comments I saw were like the parent comment above - a bunch of bleating from a group of pussies who are still cowering after Sept 11, 2001, waiting for the gubermint to protect them from any and all potential harm or risk.
I grew up on sci-fi, reading about the possibilities - things humanity can do if it sets out to accomplish something grand. Bike helmets didn't exist, I ate dirt, skinned my knees climbing trees, and broke bones on (unsafe by today's standards) playground equipment. I dreamed of the stars, and of people inhabiting the entire solar system one day.
Which is worse - mining the asteroid belt or open pit mines in sensitive areas? I fully recognize that sci-fi has as much fantasy as science, but I recall novels from the 1980s that included LEO refining of asteroids, followed by dropping the materials down to earth by shaping them into gliders or capsules similar to those used in the Mercury program. There should be enough silica waste to make some heat-resistant tiles up there, and the metal can be foamed or made hollow to drop the density.
If the first few comments are representative of today's /. audience, no wonder CmdrTaco bailed.
Slashdot - the place where you can look like a genius by restating the obvious
Whyever would you return the output of your mine to Earth?
The primary value of a bug chunk of rock and metal in orbit is that it's cheaper to make things from it than to haul the same amount of metal into space.
Right now, one of our big limiters on space activity is that we have to move EVERYTHING out of a deep gravity well to get it into space at all. If we can eliminate the need to move, say, the structural mass of a solar power satellite into orbit, we can reduce the cost of solar power satellites by an order of magnitude or three.
Ditto anything else we want up there....
"I do not agree with what you say, but I will defend to the death your right to say it"
How does doing or not doing any of those things have any effect on whether or not they can capture an asteroid?
Suso would like China to get their shit together regarding some of these more common failings before trying to snatch an asteroid out of the sky with their as-of-yet undeveloped space chopsticks.
This isn't 'The Chinese' (as in the Government) its some Chinese guys at a university in Beijing with a crazy idea they posted on Arxiv. Arxiv is not the place that the Chinese government will be posting their world domination plans.
You want to move Mars and Venus into Earth orbit?
Disclaimer: Evolution comes with NO WARRANTY, except for the IMPLIED WARRANTY of FITNESS FOR A PARTICULAR PURPOSE.
Do you really think that this type of endeavor could ever take place without governmental involvement?
I think that was the point he was making.
First off, all of the Lagrange points are further from Earth than the moon.
Not quite.
Notice this diagram of the earth-moon system at:
http://en.wikipedia.org/wiki/Lagrangian_point
Points L3, L4 and L5 are all at very nearly the same distance as the moon. L1 is actually closer. Only L2 is significantly farther away. Technically, the more the biggest body is larger than the secondary, the more the 3, 4, and 5 points will tend to fall slightly beyond the secondary's orbit, So for the Sun-Earth system, the L3, L4, and L5 are slightly outside Earth's orbit. But, the Earth is not as much proportionately greater than the Moon, and the 'points' are actually larger than pure points so for the Earth-Moon system, L#, 4, and 5 fall partly inside and partly outside the Moon's orbit.
You are, however, quite right that putting an object at a Lagrangian point doesn't keep it there. The range of velocities that are even semi-stable is pretty narrow, and for points L1, L2, and L3, the stability is in a plane perpendicular to the two major bodies, and there really is no gain in stability along the line between them, Every time we have parked a satellite at one of these points, it has been by using station keeping thrusters to give it an occasional nudge to keep it there. It's cheap on thrust, but not free. You're also right that the points have naturally attracted stuff already and tend to be cluttered spots. I don't know if that really affects costs or risks - there have been solar observation satellite missions to the sun-earth Lagrangian points, where the same problems should apply, and these have worked well so far.
Because the orbits of the various major bodies are elliptical, the Lagrangians aren't really points. If there weren't other planets and such around, the orbits would be roughly kidney bean shaped, but since there are, objects tend to be pretty close to stable in complex orbits called Lissajous orbits. Making those fairly large may be a way to avoid some debris.
Who is John Cabal?
Falling off of a playground gym won't result in a crater the size of a medium-sized city.
If it was my sister that fell it sure would.