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NASA Asteroid Capture Mission To Be Proposed In 2014 Budget
MarkWhittington writes "Included in President Obama's 2014 budget request will be a $100 million line item for NASA for a mission to capture and bring an asteroid to a high orbit around the moon where it will be explored by astronauts. Whether the $2.6 billion mission is a replacement or a supplement to the president's planned human mission to an asteroid is unclear. The proposal was first developed by the Keck Institite in April, 2012 and has achieved new impetus due to the meteor incident over Russia and new fears of killer asteroids."
Is this a real word? asteroinauts? really?
This is a program designed to be cut, to show that this administration is being 'fiscally responsible'... I expect many such 'pie-in-the-sky' projects to be proposed, only to be cut at the altar of fiscal responsibility... And blame the minority party for the cut as well.
Hey, if they can count as savings the money they don't spend on wars that have ended, why not propose wild plans to pump up the savings?
Do you know how much (in inflation-adjusted dollars) we have saved since we stopped fighting the Second World War these last 65+ years?!?!?!
Ken
catching a 7 meter 500 ton space rock has nothing whatever to do with diverting dangerous asteroids or killer asteroids or even the mostly annoying asteroid that broke Russian windows. Real asteroid diversion would use tutally different tactics over many months or years, provided early enough warning was had.
That was extremely poetic. I'll be surprised if that doesn't make it into the quote list.
". . . can I keep it . . . ?"
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
But I read a post that he keeps his bitcoin wallet there!
An asteroinaut?
Silence is a state of mime.
Since all the money will be spent here on earth, they can have fountains, Rolls Royces, and Yachts just by doing banker tricks with all those funds
that Boeing and General Dynamics and lowly technicians deposit from the NASA contracts.
Sig Battery depleted. Reverting to safe mode.
I think Obama has a ways to go to catch up to George Bush on vacation time.
http://www.rootstrikers.org/
L4/L5 is valuable real estate. First nation to park a base there owns it.
We should send two.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Bruce Willis and Ben Affleck don't come cheap.
Some have an "in" and other have an "out."
Seriously, wouldn't sending a handful of robotic spacecraft to characterize larger asteroids be much more worthwhile? While it could be argued that astronauts on the surface of Mars with good geologic training and tools could be more productive than a robot, I'm not sure what value sending astronauts to such a small asteroid in lunar orbit really adds.
The asteroids that really threaten Earth are an order or two of magnitude bigger -- a hundred meters to a few kilometers in size. A 7 meter asteroid may give us some insight into their composition, but it would be better to actually go an analyze the actual type of asteroids we are worried about. Knowing details of their structure and how they are held together could immediately eliminate some solutions for diverting their course if the need ever arises and provide insight that could spark creative solutions that haven't yet been thought of. This kind of work could actually be done much cheaper with robots than astronauts if what we really care about are actual results.
Human's have to get out there. Not as entertainment, but because if humans remain exclusively on this rock and in near earth orbits, humans are a sitting duck. The lessons learned in getting humans into low earth orbit, then high earth orbit, then to establish permanent bases on the Moon and Mars, are going to be used to develop longer term programs for human interstellar travel, exploration and in time colonization.
Or we can just develop robots to go out and do that for us and roll over here on earth and give up.
You never know...
plan to capture an asteroid, have something go wrong and find it breaking up an hitting several large population centres.
L2 is even more precious as it is the only fairly stable spot in the Earth-moon system where if you're not careful you fall into interplanetary space. Every other place but this requires significant delta-v to escape the Earth's or the moon's gravity. Here though, just drift a little too far from the moon and away you go.
Help stamp out iliturcy.
I don't mind if we send out robots first to make it safe and comfy for the humans who follow. As long as we get moving.
Help stamp out iliturcy.
We should be looking at getting the technology to capture LARGE asteroids instead of planning a mission to mars. If we use government funds to push private industries into getting a large rock with value into moons orbit it can provide us with a source of material to help us colonies space which is a much better goal than trying to visit mars with humans. We can continue use robots to explore mars while we work on mining space rocks for rare earths for earth and also for space and for a moon base. Perhaps it would be even better to capture a comet since the most valuable space element is water. http://rawcell.com/
L2 is even more precious as it is the only fairly stable spot in the Earth-moon system where if you're not careful you fall into interplanetary space.
L1 through L3 are not stable points. L4 and L5 have weird dynamics, but things put there will stay there with extremely low delta v.
And you can "fall" into interplanetary space very easily (that is, with arbitrarily low, but well timed delta-v) from any of the Lagrange points. L2 is not unique in this respect.
I really wish that we would test out some technologies for diverting large asteroids so that we're not trying to scramble at the last minute when we realize something large is coming our way. I'd like to know for certain that we'll be ready for when we see something coming our way that could cause us some serious pain or even extinction.
// file: mice.h
#include "frickin_lasers.h"
Well yeah, L4 and L5 are more stable. L2 requires station keeping - but not much. I don't think L1 or L3 would be very useful. You got me on the falling out piece - I had forgot. I should think habitations at L4 and L5 where they won't fall out, refining and fuel depot at L2. Anyway, as long as we're talking about exploring the solar system on a low energy budget, I suppose folks will want to read about the Interplanetary Transport Network.
Help stamp out iliturcy.
I don't think L1 or L3 would be very useful.
L1 is between Earth and the Moon. That makes it quite useful for anything going on between the two, like communications networks. It also makes a great anchor point for a space tether (something which could be made with current materials!) from the Moon.
L3 is just like L2 though a touch closer to Earth. You can park spacecraft out there with modest station keeping issues. The L2 advantage is that it's line of sight with the far side of the Moon so you can either park spacecraft that hide from Earth (when very close to the L2 point) or which can communicate with both Earth and the far side of the Moon (a halo orbit further away from L2). But if you're just looking for some place to put something, L3 will work.
Imagine seeing an astronaut by an asteroid, with the Earth and Moon in the background.
Sig: I stole this sig.
It's a handy thing to practice catching, and a handy thing to have in orbit to practice refining fuel, but L2 is not the place to do it. L1 and L2 are extremely unstable, you have to continuously consume fuel to remain there, though you can reduce the amount by orbiting them. L3 is better, but on the opposite side of the primary. L4 and L5 are where you can actually store stuff stably - that's where asteroid fields tend to naturally accumulate.
Where L2 is useful is to hide something from the primary - for example space telescopes orbiting the Earth-Sun L2 remain constantly shielded from the sun by the Earth's shadow. Or in space-elevator scenarios, where for example a cable extending from he Moon through the Earth-Moon L1 or L2 points will hang stably in tension.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I think you mostly nailed it - L1 is great as a pass-through point for a lunar elevator, which could potentially extend all the way down to geostationary orbit, obviating the need to each orbital velocities for an Earth-Moon transit. Probably *the* prime piece of orbital "real estate". Not really anything special otherwise, after all the Earth and Moon already have line of site with each other.
An L2 halo orbit would be handy for communication with the far side of the moon, though a simple collection of 3+ satellites in lunar orbit would do much the same for a far larger area with less transmission lag time, and any lunar communication satellites would destroy the radio "quiet spot" potential of using it for telescopy completely shielded from basically all earthbound and orbital signal sources. Could also send another tether through the point itself, but I don't see that that is really all that useful - a low orbiting tumbling cable space elevator would be far cheaper and more effective for launching stuff from the moon's surface out of Earth space.
L4 and L5 are handy gathering points since stuff will tend clump together and they make a pair of nice big targets for incoming asteroid captures and the like.
L3 is... just a place that's there. Can't really think of any special use for it beyond being a focal point on the Interplanetary Transport Network along with the other L-points. After all, if you're just putting something in orbit any orbit will do, and unlike L3 most of them don't require any appreciable station-keeping.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Earth-moon L3 is on the opposite side of the earth from the moon, as you know. It's a nice spot for a telescope to look for NEAs. As you pointed out it's not stable. Therefore it's not a good spot for a space station with human inhabitants. Yes, it would be a good spot for a LH2/LO2 distillery with good 0-energy transits to L2, as that sort of operation could manage their stationkeeping by changing the orientation of their thermal outputs. But refining is a messy business that messes up telescopes, so it's best if we reserved that one for astronomy. L2's angular momentum makes it a better fuel depot and jumping off spot for people in a hurry, like humans vulnerable to cosmic radiation. I think L3 is the "least best" of all the Earth-moon Lagrange points. It's where you park the least important stuff. Computing a vector from L3 to interplanetary missions seems more iffy to me than L2, which is relatively straightforward. Almost all of the paths from L3 to interplanetary space lead through L2 anyway.
Earth-moon L2 is permanently eclipsed from Earth by the moon. We can't see it from here. That's a downside. As a relay for the far side of the moon you're right: it works - as long as we have relays in orbit around the moon to relay to it. Just one would do, in a polar orbit around the moon on a plane perpendicular to the earth-moon angle, or close to it. That lunar satellite though would then have almost all the coverage L2 would directly except for the smallest "polar" patch pointed at L2 hidden by terrain. On the upside there is no more angular momentum advantaged path to interplanetary space than Earth-moon L2. Not even sun-Earth L2.
Getting to Earth-moon L3 and then killing your inertia seems costly in Delta-V to me relative to L2. Of course having their proximate gravity well L4 and L5 don't have this as much of a problem. Care to weigh in on that? You seem to know more about this than I do.
Of course all of the Lagrange points are part of an interplanetary highway that after 4 billion years have some traffic flowing. For capturing asteroids with robots this is good. For human habitation it may be bad.
Help stamp out iliturcy.
Earth-moon L2 is permanently eclipsed from Earth by the moon. We can't see it from here.
But a spacecraft can orbit the Earth-Moon L2 (via a halo orbit) far enough away and have line of sight with Earth.
Nothing there to tax.
Ok, so once the asteroid collector has delivered the asteroid to high lunar orbit, what does the spacecraft do then?
Well, if its got even a tiny fraction of its propellant left over (remember it just towed something maybe 100x its size clear across the inner solar system) , it slowly spirals down to low earth orbit and... REFUELS.
Now here's where things get interesting. Once it's refueled (remember its main consumable is up to 12,000 lbs. of Xenon, it gets its energy from solar power), it can do any number of things. Of course it could be sent out again to get another asteroid (including, as I mentioned in a previous post, one with precious WATER) but that might be boring. How about having it PAY FOR ITSELF by moving satellites from LEO to geosynchronous orbit. (This is very expensive as it typically requires an additional booster, I think the cost per pound is at least double that to low orbit). I think this market is on the order of $5B per year.
The reason why this would work is because the asteroid tug would clearly be capable of moving very(!) large payloads. It wouldn't even have to be very slow, if it can accelerate a 500 ton asteroid at 1/10,000th of a g, it could accelerate a 5 ton satellite at say 1/200th of a gee (taking into account the tug's own weight). So it could deliver the satellites in weeks if not days. Of course there would need to be a few minor design modifications to the tug. The collapsible "bag" would have to be removable and some sort of industry standard docking ports added. There would need to be some provision for refueling ports and critical components (gyroscopes, reaction wheels, electronics) would need to be replaceable/upgradeable like the Hubble space telescope. Of course servicing this "space tug" in this way is probably beyond the near term capabilities of robotics. However, rather than this being a problem, it could be an opportunity -
- for the International Space Station to actually be USEFUL. Here it could serve as a fuel depot, servicing "garage" and interchange point for these "space tugs". The kind of problem that robotics can't handle yet are ideally suited for an astronaut with a wrench (and maybe some elbow grease). The fact that the main propellant for these tugs is Xenon, an inert noble element, makes handling the fuel much less problematic (no problems with corrosion or toxicity) and safer (no fear of explosive combustion). Even the fact that these tugs use ion thrusters would be an advantage meaning that everything would be happening very slowly, if one went out of control they could probably move the entire station out of the way (like they do when avoiding space junk). The station could also keep spare, interchangeable parts for these tugs such as additional "bags" or robot arms or other modules. In short, the ISS would have a PURPOSE.
With even a little thought, these space tugs have lots of additional uses. The same high power ion engines that can move a 500 ton asteroid could also send 500 tons of cargo cheaply (if slowly) to Mars. The same collapsible bag that can capture a tumbling asteroid can easily capture a much lighter piece of space junk. All it takes is for a government with foresight to make the initial investment that may (as I've suggested) quickly repay itself perhaps many times over. And isn't that the purpose of government (if not NASA)?
(By the way, putting the mini-asteroid in high lunar orbit may be useful as a last resort because, if we detect a threatening object heading our way, it might be in a good position that we could put the mini-asteroid on a new trajectory to hit the object and thus deflect it out of the way. With luck the 500 ton mass will strike the incoming object at a high incidental angle and at a significant velocity since it'll be coming from a completely different orbit. Of course it would be much preferred to nudge the incoming object years before in deep space off of an intercept trajectory but if we're caught with our pants down it would be nice to have a big rock whirling in the sling of its lunar orbit. In that case, we coud call it "David's Rock" or "The Goliath Killer".)
Only when you count Bush going to the ranch that was his personal property from before he was elected, then yes. Somehow, I don't think Bush was charging the Office of the President for time spent there.
Even when there's pork and fanboys involved, mankind will advance by being challenged and a challenge is much more rewarding the harder it is to achieve.
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> L1 is great as a pass-through point for a lunar elevator,
Rotovator/Skyhook type rotating elevators are demonstrably better in mass ratio, transit time, and meteor exposure than a stationary elevator.
Assume you want to take off and land from the Moon, and your rotating elevator is designed for a comfortable 1 gravity at the tips. Lunar orbit velocity @ 280 km altitude is 1560 m/s. To have an equal rotation tip velocity @ 1 g you need a 248 km radius. Thus the tip becomes motionless over the Lunar surface at about 30 km altitude (we want some clearance to avoid mountains and for orbit shifts). The rotation period is 1000 seconds. If you wait half a rotation and let go, you are moving at twice orbit velocity, because the velocity of tip + orbit motion of the center of the structure now add instead of cancel. This is more than enough to escape the Moon. By climbing some part of the 248 km radius and timing when you let go, you can inject to a wide range of orbits. Compare this to climbing a 60,000 km stationary elevator to Earth-Moon L1. It takes longer, and is more limited in destinations. Not to mention 120 times less exposure to damage from meteoroids.
As far as materials required, the acceleration varies linearly from center to tip, so it is equivalent to 124 km stress at 1 gravity. Carbon fiber has a scale length of 360 km ( http://upload.wikimedia.org/wikipedia/commons/d/d4/Materials_Scale_Height_and_Tip_Velocity.PNG ). Allowing a 2.8 reduction of the breaking strength for factor of safety and structural overhead, we get 128 km design scale. Rotating structures need to taper by a factor of e per design scale, so this Rotovator would taper by a factor of 2.8 from center to tip. This is quite reasonable as a design.
Personally I envisioned a rotovator (fine name, I'll have to remeber that) where the tether ended in a secondary adjustable-length tether on a long winch that could be extended to almost graze the surface at the "touchdown" point, allowing it to lift objects directly from the surface where their motion would be completely predictable, minimizing the coordination complexity. You'd just need some sort of maneuvering thrusters at the very end of the tether.
And the properties are even better than you suggest. I sat down a while back and worked out the math for a rotating elevator who's end becomes geostationary (luna-stationary?) at it's lowest point, and one of the interesting properties is that for a given lower altitude, the shorter your cable the more energy it will impart. I don't have the exact numbers handy, but a fairly small lunar rotovator that never even reaches 1g can not only impart enough momentum to escape lunar orbit but, depending on the relative position of elevator, Moon, and Earth during release, easily escape Earth as well, with enough delta-V to be on a transfer orbit to beyond the orbits of either Mars or Venus.
The biggest potential problem I saw was that it's not possible to build a "lunar-stationary rotovator" who's payload energy at maxima is compatible with a transfer to Earth orbit - the tether would have to be longer than the Earth-Moon distance. That means that Earth-destined transfers would have to be released with only a small fraction of the possible energy, and more worryingly that Earth->Moon transfers would have to dive-bomb the Moon and catch the tether at nearly the last moment when it's velocity matched. Any mistake and there would be no way to avoid an extremely energetic impact. And since one of the biggest benefits of a rotovator is that it can act as a "momentum bank" to allow transfer to/from orbit without energy consumption that's as far as I pursued the idea.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Naturally, you get modded down. These people are suckers for aerospace industry lobbyists.