Cutbacks to NASA Funds for Asteroid Detection

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http://www.cnn.com/2009/TECH/space/08/13/nasa.asteroid.detection/index.html

I think it really shows how America is the Big Brother of the rest of the world. We are willing to allocate tons of cash to help protect the world against disasters from space, no matter how unlikely they are....

 

I really think that identifying the asteroids is not necessary until we have a way of stopping them.

 

We still have to develp and improve our range of what we can see, otherwise trying to develop a means to stopping them is useless. We just need to develop a Space Station or Spacecraft that can launch at them, destroying or changing the path of the object. I would think they are equally important. We have got the easy part down now, identifying them, now the hard part is ahead of us...

 

For T2, once an object is identified (outside of the asteroid belt), it's pretty easy to plot it's course through space for a hundred years. We aren't just looking for things that'll threaten Earth tomorrow, but also in the future.

For Blades, I'd imagine we could launch some re-programmed ICBMs to alter an incomming object's course significantly, or even shatter it into insubstantial pieces. Many of them have exit-velocity potential already, and it's not like the asteroid is taking any evasive action. Even if you're worried about a near-miss, adding a few simple directional thrusters that can be remotely fired after launch and you're almost guaranteed impact.

 

NOG - I would think it is all about the Mass, Density and the Speed of the object. I'm no scientist, so don't quote me on that outside of these boards though. Can we actually alter the course of a Big Asteroid? Even if we hit it, will it make a difference?

 

I understand how all this works. I just don't see the point if all that can happen is mass hysteria. There really is no reason for the project until we have the means to stop a large asteroid or comet. It is certainly a good thing for the future, but until we can send Bruce and Ben up to stop the damn thing it's just wasted money. This is a congressional knee jerk reaction to Hollywood imagination -- no one was concerned after Lucifer's Hammer was written, probably because most law makers don't seem to read.

I'm also not sure why it should be funded 100% by the US.

We can't consistently hit an ICBM with a seeker missile that was specifically designed for that purpose. Why would you think we could reprogram and send an ICBM and successfully hit an asteroid travelling many times faster than the missile?

 

T2 - I don't think we should foot the bill, but apparently nobody else is willing to ante up, so we're stuck doing it ourselves. Though I would prefer that we were the only ones with the Technology, for future security reasons.

 

I'd have to do some serious math to be sure, but I'd bet a few of our nuclear warheads could alter most anything that's coming at us, especially if we can get to it soon enough. If we see it coming while it's still all the way out at Mars, a very tiny impact could radically alter it's course. Now, there are a few asteroids out there that are large enough to cause serious trouble, but they're also large enough to be spotted by telescope a long, long time before they hit us.

The ICBM takes a total flight time of, at most, a few hours, and can be noticably impacted by wind (not enough to miss a target with a nuke, but enough for the missle to miss). For the asteroid to be so close that it'd hit us in a few hours, it'd probably be well within the orbit of the Moon. We're talking something that's already reached a distance that astronomers would call it a bullet-burn pass if it didn't hit us. I'm thinking launching while it's still days away, and then having the ability to correct course durring those several days. Plus, there's no real wind in space.

Because we can (or at least could for a while) afford it.

 

I would think just a hit is not enough though. If it's big, we would probably need a precise location to hit, in order to alter the path of the asteroid.

 

Again, that depends on a lot of factors, but remember that the larger it is, the less precise you need to be with a hit. If it's the size of a mountain, you may need to hit within a few feet of a particular point to change it's course the way you want. If it's the size of a large city, you may be talking about a square mile or more.

And as for whether hitting it is enough, it depends on the mass. Really, there's little difference between a force applied instantaneously and a force applied over time, so long as the amount of kinetic energy transfered is the same.

 

I don't think it would quite be the same as playing Asteroids on BoM Arcade.

We are currently talking about it taking months to send a vehicle to Mars at its closest trajectory -- how far away do we need to hit a planet killer with a 120 megaton warhead (or a pack of ten such warheads, or a hundred) to really have an effect on the trajectory so it will clear without damaging the moon as well? Such missile would be traveling for weeks.

An asteroid that is only 450 meters across could be vaporized by a large enough warhead, but you're talking about trying to hit a 450 meter wide target at a distance of 10 million miles, maybe only a million (that would be cutting it real close). That's not much room for error. You certainly don't want to be waiting until the thing is within the orbit of the moon -- that's just suicide.

Perhaps we have the capability of stopping a planet killer, I have my doubts we could stop one with a piecemeal combination of ICBM's strapped to a Saturn V booster.

Edit: Oh, yes. Would a surface impact have much affect? I think you would need to develop a weapon with sufficient penetration power to truly focus the blast and redirect the asteroid/comet -- such a weapon doesn't exist right now. Especially when you consider the asteroid's rotation and the direction of the blast would need to be fairly exact.

 

The theory I heard is that you'd want to get it when it was far away. One option would be to get a fairly small object with a thruster, and actually land it on the asteroid, and then fire the thruster. Even though the mass of the lander and the power of the thruster is miniscule compared to the size of the asteroid, if you do this when it is far away, altering the asteroids course by a fraction of a degree is enough to change it's tragectory into a safe orbit. When the object is 10 million miles away, a one degree course alteration moves the object tens of thousands of miles away from it's intial course.

EDIT: And yes, we currently have the technology to land an orbiter on an asteroid. In fact, we've already done it. (Granted the one we landed didn't have a thruster attached because the goal of the mission was not to change the asteroid's course.

 

When these are the odds, I think I can sleep peacefully without the detection funds.

 

Yes, but that's not a problem. Once launched, the missle doesn't need to do anything but coast until it nears the point of convergence, then it can easily fix on the actual target and recalculate it's course. At this point, we're talking about math and programming my calculator could probably do.

It would be guided, and able to self-correct it's course on the way.

It depends on the desired affect. If you're trying to destroy the object, a surface impact wouldn't likely do too much, though it'd likely make a sizable impact on the smaller objects (like that 450 meter target). If you just want to alter the course, it doesn't really make all that much difference. It'd be best to target it at the center of a crater or crevice to try and focus the blast a little, but it probably wouldn't increase effective force much more than a few percent.

Yes, this is the idea. The farther away the object is, the slighter the course correction needs to be.

That is one option, and is definitely feasible with modern technology, but we'd actually have to build it.

Actually, it's goal wasn't even to land on the asteroid (it wasn't expected to work), but it had already completed all other mission parameters, well outlived it's projected lifespan, and was unable to completely escape the orbit of the asteroid it was orbitting (low on fuel). Most impressive of all was that neither machine nor programming were ever designed to handle a landing of any kind, much less on an asteroid, but were able to handle it (the acual landing was performed by the probe's AI, one of it's many experimental systems, and was considered one of the AIs more impressive feats).

 

In theory such a thing could work. I've seen missile launches. I know their accuracy. We don't have a missile that good.

 

I think that if we saw something that was coming at us and was going to hit us in a few years, we'd be pretty quick to get the tech assembled and the rockets built.

IMHO, we have more pressing problems here and now on the planet that need some more funding.

 

The last reserve unit I was in, half of us supported the Naval Research Labs, the other half supported Stennis Space Center. Granted that was about five years ago, but I just don't have as much confidence as other do on the boards that NASA could pull off an Armegeddon type mission.