Dueling over asteroids

Des Emery,The Carborundum Chronicles,St.Thomas,ON, Canada — Thu, 22 Mar 2007 01:31:15 GMT

Hi, Alan -- Having a real astronaut - one who is familiar with space - is a plus for that gravity tractor discussed a while ago here. The time element was not considered then. I can see a massive rocket in solar orbit like the asteroid moving along and changing the latter's orbit little by little by virtue of the rocket's attraction. Myself, I still like the idea of that rocket getting behind the asteroid and changing its velocity by using a blunt snowplow mounted on it nose and firing intermittently to put the asteroid into a new orbit.

Dueling over asteroids

Mike Moore, Los Alamos, NM — Thu, 22 Mar 2007 01:49:47 GMT

When one has lemons, make lemonaide. Instead of deflecting the asteroid, why not capture it in high Earth or Lunar Orbit and mine the metals, which can typically be worth a trillion, trillion, trillion dollars in nickel iron meteorites. The asteroid capture project!

Dueling over asteroids

Bill — Thu, 22 Mar 2007 02:22:27 GMT

how many trillion, trillion, trillion, trillion, trillion dollars worth of technology would be required to change a trillion, trillion, trillion dollars of nickel from a solar-centric, hyperbolic orbit into an earth-centric orbit?

Dueling over asteroids

charles ritz, fort lauderdale, florida — Thu, 22 Mar 2007 02:29:36 GMT

i agree with mr moore there 100%! let's hope its big enough to hollow out and tie a microfilament (we arent that far away from a space elevator really...) to one end and spin it in stationary orbit over either brazil (preferred) or africa (um... obviously we dont want any body THERE to have the keys to the next step for humanity to take...!lol humans suck still!) but anyway i digress... seriously... invest in that and be richer than you might believe within just 20 years. because that would eliminate the cost of fuel to get into orbit! grab 4 of them!!

Dueling over asteroids

Chris, Toledo, OH — Thu, 22 Mar 2007 02:35:49 GMT

It would actually be pretty cheap to move it into orbit if it's not posing an immediate threat of impacting Earth. The math isn't anything we haven't been doing since the Apollo program, and if a probe or two are sent to it to show surface topography it would be easy to pin down where it is and figure out where to attach anything if you're going to shove it with a chemical rocket. The real trick to it is getting the technology to mine it effectively, but once that hurdle's been passed, whoever's figured it out is pretty much going to be the richest person on the face of the planet.

Dueling over asteroids

Chris — Thu, 22 Mar 2007 03:29:16 GMT

You don't try to move it into orbit, you mine it right where it is to build whatever you want. If it had water ice, it would be all you need itself!

Dueling over asteroids

Russ — Thu, 22 Mar 2007 03:42:41 GMT

There's no need to deflect them... just tether to the projectile at a 45 deg angle and slow down... the effect would be to divert the objects tangent to wherever you let it go.

Dueling over asteroids

Robert Murdock — Thu, 22 Mar 2007 04:04:15 GMT

I don't understand how a stand-off nuclear blast is going to do much of anything without air to carry a shock-wave to the object. You would only have a few hundred pounds of matter even with a shaped charge and only a small amount of that is going to impact the object, most of it will be coverted to radition that will only act on the object for maybe a second or two. It looks to me that ramming the asteroid with a ten ton projectile at around twenty thousand miles an hour would be far more effective.

Dueling over asteroids

Andy, Michigan — Thu, 22 Mar 2007 04:32:18 GMT

Actually it's not a bad idea if there is enough lead time. Any asteroid flagged as a potential threat would be moved to the top of the mining list. The space miners converge on it and by the time it reaches earth its all broken down into raw materials.

You were going to have to send a rocket to it anyway and all the raw materials would pay the cost of the operation.

Dueling over asteroids

Dan Vancouver WA — Thu, 22 Mar 2007 04:48:17 GMT

I don't know about most people, but what gives me the willies is people that are too politically correct to acccept setting of a nuke harmlessly in space to prevent the devastation of a city on earth.

Dueling over asteroids

Jeff Spellman, Bellevue, Washington — Thu, 22 Mar 2007 06:41:10 GMT

It seems to me that the nuclear option would be the clear winner - wouldn't the impulse from a tractor be severely limited by the mass of fuel that could be carried up to the asteroid and ejected through the tractor's engines? A nuclear detonation on the asteroid surface, on the other hand, would deliver an impulse to the asteroid by accelerating mass which is already up there.

Dueling over asteroids

Andrew Stec Trucksville PA — Thu, 22 Mar 2007 11:34:32 GMT

STOP WASTING TIME AND MONEY ON SOMETHING THAT IS ALREADY OBSERVED AND CONTROLLED BY FORCES MORE ADVANCED THAN ANY WEAPONS SYSTEM. STOP KILLING THE VERY PLANET THAT NURTURES US AND GROW YOUR SOUL INSTEAD.
WATER AND SOIL ARE BEING POISONED, CHILDREN ARE STARVING, STUPID WARS ARE CONCOCTED FOR PURE PROFIT AND POWER AND YOU FEAR WHAT MIGHT BE? DO SOMETHING ABOUT WHAT IS!!!!!!!!!! Grow Up! Evolve! That is why we are here.

Read Hidden Truth, Forbidden Knowledge by Stephen M. Greer M.D. and the curtain shall be lifted. I promise.

Dueling over asteroids

Larry Wolf — Thu, 22 Mar 2007 11:48:23 GMT

Get a life webmaster! Your fixed fonts that can't be zoomed or resized make reading your material impossible for seeing impaired. Jerks

Dueling over asteroids

PiFfy StifFiNz — Thu, 22 Mar 2007 12:42:01 GMT

How about we track smaller asteroids and secretly guide them into trajectories that will impact our enemies. That way it looks like an act of God. None the wiser. Not to mention really cool TV!

Dueling over asteroids

Astrochronic — Thu, 22 Mar 2007 12:48:33 GMT

In the future that sort of mining may be feasible, in fact it may become necessary. First, though we need to get back to the moon and then we need to go to mars. Before we can do any of that we need to get these crazy terrorists under control.

Dueling over asteroids

Patrick Coyle, Seale, AL — Thu, 22 Mar 2007 12:53:12 GMT

A low-impulse, ion engine powered by solar energy over long periods of time could cause a significant change in orbit.

Instead of trying to capture such an asteroid for its mineral content, why not crash it into the Moon? We could then mine it there. This would probably take much less delta V. This would also provide a great deal of cheap data on lunar morphology.

There are lots of possibilities. The NASA mind set does not necessarily encourage thinking out side of the box. They do have limited resources and they are being increasingly focused on manned space exploration (which I frankly applaud).

Why not a Federal contract with the B612 Foundation (or similar NGO) to examine a wide range (as all encompassing as possible; silly to the sublime) of options to deal with the potential problem. Then we can have a serious international discussion of the options. After all, this is an international problem.

Dueling over asteroids

Michael, ATL, GA — Thu, 22 Mar 2007 14:09:31 GMT

This threat is far greater than any potential terrorist attack. This is the real hidden enemy of the people of the world. Unless we figure this out, we all may be doomed. Instead of spending money fighting each other, we need to wake up and look at the real potential killers of humanity.

Dueling over asteroids

J.R. PRESCOTT, LEESVILLE, LA. — Thu, 22 Mar 2007 15:11:06 GMT

Several cultures, including the Mayans, predicted collisions within a specific time-frame, but obviously had no plan for dealing with it. They probably realized the futility of trying something other than migration. Personally, I'm not so much concerned with the ones we know about; I'm worried about the ones we DON'T see. Our space budget is sadly underfunded, both for travel and research, and relocation on another planet(Mars, with its caves?) might best be looked into in order to perpetuate the species.

Dueling over asteroids

Alan Sheets, Loveland CO — Thu, 22 Mar 2007 16:19:44 GMT

Rusty may be a former astronaut, be he seems to have forgotten that NASA doesn't have any heavy lift capabilities right. A gravity tractor would have to have a lot of mass to do any serious deflecting, and would need a long lead time to do the job. That means it has to get launched at escape velocity, get to the asteroid fast, and then maneuver around. The tractor would have to probably be bigger than the ISS to do the required job. How long and how many launches has it taken to get ISS to its present mass, while being stuck in LEO and completely unmaneuverable?

On the other hand, an existing nuke or 3 could be launced by an existing Delta 4 or Atlas 5 rocket and get to any place beyond Jupiter in less than 3 years.

I like the idea of trying to capture asteroid in Earth orbit -- and it would be easy enough to do with a solar (or nuclear) powered magnetic rail mass launcher. It would work about the same as bringing an iceberg to Los Angeles to provide fresh water -- about half the mass would be gone by the time it would arrive, but there would still be plenty left over for profitable purposes.

Dueling over asteroids

Howard White — Thu, 22 Mar 2007 16:35:20 GMT

Why the apathy by so many as to the future destruction of maybe the entire population of the planet earth?We are so involved with fighting among ourselves that we have lost sight that we are on the same voyage through space ,on the same ship(Planet Earth),and TOGETHER!If we stop for a minute and reflect, we could unite and figure out ,ahead of time,what we should do to stop NEO,s from destroying life as we know it. I hope someone can convince the world that this ranks at least as important as the next world Olympics or U.N.Security Council meeting!!

Dueling over asteroids

Sid Goldstein, North East, PA — Thu, 22 Mar 2007 16:56:29 GMT

No need to change the orbit for mining. Just mine in place and deliver finished products or raw materials to orbital space factories. Any viable technology to change an object's orbit can't produce future hazards to navigation, so forget about blowing it up. Developing only the technolgy dicussed here to change the orbit assumes we have enough time to get there and affect the change. What if we discover an object that will impact before we can physically get there? For that, the only protection that would work would be a directed energy beam of some sort, (e.g. lazer or microwave) that could impart a velocity change by vaporizing the surface. We should spend the money do develop detection and all deflection technologies at the same time, now, before it's too late. Cosmic protection won't be cheap, but it will be a lot less expensive than the alternative (remember Katrina?). The time for talk has passed. Make it so now.

Dueling over asteroids

Bruce Ellison — Thu, 22 Mar 2007 18:02:04 GMT

Here's an idea. Lets all talk about it for the next 50 years and hope one of these things doesn't land in our back yard.Whatever they/we/you/me or whoever does we better do it soon or it will be too late.Sooner or later one of these things is going to hit us.If we take all the money we pour into the "Oil War" and the dollars we throw away everything else we would already have a solution.But that won't happen.Because we're all Idiots.Listen to the astronauts who have been in space. I trust them a whole lot more than some egg-head in a suit who is only worried about how big a jet he gets when he/she is elected to office.Ah what the heck. Lets just worry about what everyone is wearing to the oscars and if Britney will make it through rehab ok.Thats the REALLY important stuff..Yeah lets worry about the cost.What a bunch of schmoes.Get your head out of the sand, people.

Dueling over asteroids

Bruce Ellison Millersville md — Thu, 22 Mar 2007 18:04:25 GMT

Andrew from Trucksville Pa--Well said.End of comment

Dueling over asteroids

Frank, Dallas, TX — Thu, 22 Mar 2007 18:29:42 GMT

I don't fully understand what's wrong with breaking an asteroid into smaller pieces. The portion of the asteroid that burns up in the atmosphere is a function of its surface area, and to increase that surface area is to reduce the mass of material that reaches the ground. A model of this would be to take two bowls of water, and to drop equals masses of sugar (one a cube, and one granulated) and to observe in which bowl the sugar impacts the bottom harder.

It doesn't totally make your problem go away, but I'd rather have a survivable catastrophe than an unsurviveable impact any day.

Obviously, your first choice would be to make the asteroid miss earth altogether, but that to even be an option means the asteroid has to be discovered while it is extremely far away, and then it has to intercepted while it is still very far away.

If there's no time, breaking it into pieces is probably better than nothing.

The downfall to this approach would be if you break it up in such a way that the pieces are still close together. If that happens, when the first piece hits the atmosphere it could create a "hole" that the second piece would zip through without burning up at all. That would indeed make it worse than doing nothing at all, but for that to happen you'd have to break it up in a way that each piece had an extremely low delta v. As long as you use a sufficiently large explosion, that shouldn't be a problem.

None of this relies on "shockwaves in space" (nearly an oxymoron) to work. Direct vaporization of material can happen with a direct impact (if the asteroid is small enough or your nuke big enough), whereas a standoff explosion would vaporize a small part of it (and hopefully not break it up in a low delta v manner) which would change the object's mass, inertia, and orbit.

And lastly, knowing something about the object you are trying to blow up would be a good idea too. Some asteroids are very low density, some are nothing but flying rock piles, some are almost solid iron; each of these would require a different size explosion relative to its mass. Oh yeah, nailing down the thing's mass before launching rockets would be a good idea too.

Dueling over asteroids

Sam S, E. Brunswick, NJ — Thu, 22 Mar 2007 19:46:19 GMT

I would hope that there could be a global cooperation for the gravity tractor idea. In the sci-fi book series Red Mars (along with Blue and Green), there was mention of putting some of these objects in orbit of Mars.

I remember that there was the high impact satellite that was launched by Japan (possibly someone else). Would something like that work to start the deflection of larger objects? To get these high impact kind of devices, ion engines could be used. Until a space elevator is up and running, we would could to build some pieces here on Earth and do the final assembly in space if it is too large to launch on a rocket or shuttle replacement.

I would hope that in the future we could put some of these objects together and build a complex within them; it might make for a different kind of long term spacecraft. If it is large enough, then it might be possible to make a generational spacecraft to explore to the next star system in something a little more durable than what we can make now.

Dueling over asteroids

Joe, Houston — Thu, 22 Mar 2007 19:56:13 GMT

Has anyone considered the possibility that an asteroid strike may not be all that bad? Sure, there will be mass extinctions. But EVERYTHING likely won't die, since EVERYTHING didn't die in the previous massive asteroid strikes. Besides, if you're one of the ones that fails to survive the astroid strike, you're not going to really give a rip about living conditions on our little blue dot. And if you do manage to survive the strike, look on the bright side--real estate will be CHEAP CHEAP CHEAP and you'll have your pick of just about any of the prime spots on the planet!

Dueling over asteroids

Frank Glover Rochester, NY — Thu, 22 Mar 2007 21:51:35 GMT

To Robert Murdock: Search on 'Project Orion' (not the current spacecraft design, but the old nuclear pulse proposal) They did plenty of study on how a nuclear detonation in space can propel an object. (though the physics of an asteroid will be different from a pusher plate optomized to get the most from the interaction, which already concerns some people...it may work with fairly solid asteroids, but have minimal effect on loosely bound 'rubble pile' objects)

To Andrew Stec: Other people are working on all those other things. (but you may not find them in an obviously space-oriented website) Are we a civilization that can't walk and chew gum at the same time? It can be argued that the dinosaurs didn't get the *chance* to evolve much more, because they didn't have the ability to address asteroid threats...

Dueling over asteroids

Gaetano Marano - Italy — Thu, 22 Mar 2007 23:07:44 GMT

.
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I'm sorry, but I think we can do (nearly) NOTHING to move/break an asteroid with to-day's space technology and vehicles... and, unfortunately, the only vehicle that can "assemble something" in space (the Shuttle) will be retired soon...

so, just cross your fingers... :)

.
.

Dueling over asteroids

Chris — Thu, 22 Mar 2007 23:28:32 GMT

I agree with Frank from Dallas who said in regard to using nukes: "If there's no time, breaking it into pieces is probably better than nothing."

Smaller pieces = more surface area = less damage to Earth! I'd also think that as the individual pieces came in, you could use standard nuclear missiles and MIRVs to target them in the upper atmosphere. A nuke would vaporized a pretty significant chunk... Ever hear about how entire islands are now gone in the Pacific?

Frank Glover, thanks for pointing out how Orion was designed to use the push of the blast. I, too, was one of those wondering if there really would be a shockwave in space.

Dueling over asteroids

Joe, Seattle, Wa. — Fri, 23 Mar 2007 00:44:43 GMT

Hypothetically, A NEO is destroyed in Near Earth Orbit by Using the 'deflect' with a Nuclear warhead in space. If the Asteroid WASN'T Diverted or in fact did break up into Hundreds of smaller pieces by using the Nuke, Would those pieces (or Whole Asteroid) be radioactive when they come through Earth's Atmosphere? When they hit Earth, wouldn't that be worse than a nuclear device going off? Radiation City All around.

Dueling over asteroids

Jonathan Burns, Melbourne, Vic., Australia — Fri, 23 Mar 2007 01:32:06 GMT

There's an approach which would suit some asteroids, given some proto-mining apparatus. I haven't seen any actual study of it, but it seems worth investigating.

Most asteroids should have some rotation; in fact, there's recent evidence for a solar radiation driven spin-up mechanism. There will be a distance from the axis of rotation at which centrifugal force exceeds the asteroid's gravitation.

Anchor a tether, initially with an explosive piton fired from beyond the radius; let it reel out to the radius times two or three.

Fasten to the tether a bucket chain or conveyor belt in the form of a closed loop.

Place on the asteroid surface a crushing and pulverising mechanism, with an initial energy source - 10-100 kW should do as a minimum.

The conveyor belt is ready to operate as a siphon. Prime it, by loading the bottom buckets with dust, and hauling them up to and past the radius. As a bucket passes the radius, centrifugal force will make it pull outward on the tether. If the bucket is kept closed until it reaches a multiple of the radius, the dust content will add to the outward pull.

At a sufficient multiple of the radius, the dust is released, and moves off at a tangent. As operation continues, a disk of dust spreads out from the asteroid.

Once the system is running, the outward pull can drive the belt. In fact, with some gearing or an alternator, it can drive the pulveriser too.

Solar radiation pressure acts on the dust, gradually pushing it into a comet-like plume away from the Sun. The plume is a "gravity tug" pulling in this one direction; but one direction is all we need, to divert the asteroid. The cross-section of the plume will vary from circular to narrowly elliptical, depending on the orientation of the spin axis to the solar radial direction.

For every kilogram per second of dust added to the disk, 86.4 tonnes will be added per day. This compares to the 20 tonnes suggested for an ion-propelled gravity tug. The gravitational effect of the dust will be greater if it is released shortly above the centrifugal radius (because it won't drift far), but the drawing power of the tether will be greater if it is released at a greater multiple of the radius; this is a tradeoff, but at worst it means we sacrifice some dust.

This, I suggest, is an asteroid deflection scheme that Leonardo da Vinci could have proposed. The failure points are all mechanical, i.e. the belt or the pulveriser might get stuck. That would be a show-stopper; but it should also be a very typical exercise for contemporary astro-robotics students, especially if they have space mining ambitions.

Dueling over asteroids

JC, Fairbanks, AcK — Fri, 23 Mar 2007 01:44:32 GMT

Quite a few of the responders to this post should spend some time educating themselves about at least some basics of astrodynamics . . . like Rusty Schweickart and Edward Lu have apparently done. If you don't know, trust the words of those who DO, or take the time to learn.

Dueling over asteroids

Buck Rogers — Fri, 23 Mar 2007 06:40:10 GMT

To Joe in Seattle:
The additional radiation risk would be minimal. First, space is virtually full of radiation(every star is a nuclear chain reaction in full swing), so these asteroids have been getting bombarded by radiation for a few billion years. A standoff blast would radiate in all directions with only a small percentage of the energy striking the surface of the asteroid, The rest would be like a puff of smoke in the solar wind (which is radiation flowing from our sun). On Earth most of the radiation problems from a nuclear blast come from fallout of contaminated soil leaving a concentrated layer of radiation on surfaces, much easier to get a bad dose that way. In space, even if they vaporized a big chunk out of the asteroid and made lots of dust, most all of it would blow away in the solar wind.

Dueling over asteroids

Chris Eldridge, HBG PA — Fri, 23 Mar 2007 19:17:54 GMT

Joe from Seattle, Good thinking about the radiation as those pieces come through the atmosphere and land all over. That was totally lost on me. After thinking about it, I don't think such radiation would be all that much. We've detonated plenty of bombs here on earth that have kicked up all kinds of fallout over the years. I'd imagine that a contaminated asteroid only hit by a few nukes wouldn't be anything near what we've already done. Good thinking though!

Dueling over asteroids

Frank Glover Rochester, NY — Fri, 23 Mar 2007 21:07:48 GMT

To Joe: Merely being exposed to a nuclear detonation does not necessairily make an object radioactive. (as demonstrated in the use of radiation to preserve food by killing bacteria) It will depend on the materials (and specific isotopes) in question, the particular form of ionizing radiation (alpha particles, beta particles, x-rays, gamma rays or neutrons) and their intensity. In general, if it's close enough to the detonation to matter, it's close enough to be vaporized by absorbed light/heat, anyway...

However, last-minute shattering of an incoming object is still problematical. Depending on how massive it is and how small most of the resulting particles are, the fact that they 'burn-up' in the atmosphere means all their kinetic energy gets converted to heat in the atmosphere, instead of mostly at Earth's surface. If you've seen a lone meteor, or re-entering man-made objects, imagine enough of them, in a fairly short period of time, to make a dangerously bright patch in the sky. You could get an effect not unlike that of a very large, high altitude nuclear detonation, with signifigant light/heat still being radiated to the ground below (a large object 'skimming' the atmosphere could be dangerous for similar reasons), and you still have that material (which doesn't disappear) lingering in the upper atmosphere as well, with potential climate-altering effects, again depending on the mass.

It may well be better than nothing, but you still want to deflect the object completely clear of Earth, if at all possible...

Dueling over asteroids

Tim Gullett, San Angelo, TX — Sun, 25 Mar 2007 07:52:02 GMT

I would agree that the best way to deal with the NEO asteroid problem is to turn it into a benefit. Instead of putting them together in Earth orbit they should be nudged into one or both of the Earth-Sun Lagrange points. Far less energy would be needed. These assembled rock piles could then be used as the construction sites for future space exploration. We keep talking about how much it costs to send mass to Earth orbit. Why not use the mass that is there? Put the rocks together and use them as our first shipyards! If we are truly serious about exploring / settling the solar system and beyond we will need some frames with some serious mass. That won't be launched from Earth anytime soon.

Dueling over asteroids

Rich, Omaha NE — Mon, 26 Mar 2007 13:18:46 GMT

The "nuclear only" option is not based in science. I'm not particularly anti-nuke, just anti-ignorance. Good old gravity and Newtonian physics for me.

Also, this mining talk is rubbish. Even today, over twenty years after the last man walked on the moon, we don't have the technology to make this sort of space mining profitable. Do the math: if the moon (a mere 250,000 miles away) was made of solid gold, it wouldn't make any financial sense to go get it. It would be like driving from New York to Los Angeles because you heard gas was one penny less per gallon. There may be reasons for space mining; just don't try to sell it as profitable.

Dueling over asteroids

Harold Huff, Cat Spring, Texas — Tue, 27 Mar 2007 18:39:52 GMT

There are no options if you dont know it is coming. We need to fund finding the dangerous rocks. In a ddition we need to get off this planet in a sustainable way to insure against the one we miss. It is not a question of if but rather when.