Asteroid defense office

[Spaceception]

So NASA recently set up "The Planetary Defense Office", and I was wondering what you guys were thinking about it.

Here's a link: http://www.popularmechanics.com/space/news/a18896/nasa-creates-a-first-line-of-asteroid-defense-for-earth/

Does this give humanity a higher chance of surviving a large Asteroid impact?

Edited January 10, 2016 by Spaceception

[Scotius]

No. Not until we have some real hardware set up in space and on Earth. Until then it's just another bureaucratic money sink.

[Kaos]

I think, we can set up a system that is effective in many cases in as few as 5 years. On the other hand, I doubt that will will set up such a system in the next 30 years. A central aspect of such a system on the other hand is to track potentially dangerous objects, which is something, that is already done. Only with enough time remaining, such a system can work efficiently.

So I see 3 different answers that represent a valid interpretation of my opinion to your question; two of these are not given as answer possibility, so I voted 5 years

[fredinno]

I don't really think something like this is necessary- asteroid impacts are such a low probability thing anyways.

[Scotius]

One word: Chelyabinsk. If that rock would hold together just couple of second longer, and burst closer to the surface damage would be much worse than shattered windows and cracked walls. After all, that explosion was measured in kilotones of TNT. We can detect and track dinosaur-killers relatively easily. But city-killers are much trickier.

[fredinno]

9 minutes ago, Scotius said:

One word: Chelyabinsk. If that rock would hold together just couple of second longer, and burst closer to the surface damage would be much worse than shattered windows and cracked walls. After all, that explosion was measured in kilotones of TNT. We can detect and track dinosaur-killers relatively easily. But city-killers are much trickier.

Still, those things happen every 100 years or so.

[Shpaget]

8 minutes ago, fredinno said:

Still, those things happen every 100 years or so.

So, we're already overdue?
Tunguska 1908.

As for the original question, it can take quite a bit, depending on how you define "ready enough". The capability to redirect 100 m rock with 20 years of advance warning is quite different from redirecting a 10 km rock with 2 years warning.

Then again Chelyabinsk roid was unknown until it smacked us.

Edited January 10, 2016 by Shpaget

[Nibb31]

Events like Tunguska and Chelyabinsk are rare, and not really worth spending huge amounts of money on. The chances of them doing any significant damage (other than breaking some windows) are low. It's not worth spending billions to divert an asteroid that would only break a few windows.

[Shpaget]

If an asteroid the size of the Tunguska one hit the central Europe, Eastern US, India, Japan or any densely populated area there would be a lot more going on than a few broken windows.

Searching and tracking requires large budgets too and if you don't constantly look out for potential impactors don't be surprised when one does hit.

[GeneralVeers]

5 hours ago, Scotius said:

No. Not until we have some real hardware set up in space and on Earth. Until then it's just another bureaucratic money sink.

Actually, even before we do this, there's something else we should do first, and we already have the technology to do it.

What we should do is stick a few nuclear bombs on a remote-controlled spacecraft--some of the warheads being mounted on missiles, the others on robotic landing pods--then fly the ship out to an asteroid and test-fire the warheads against it to observe the effects. How much damage is done, how much does the asteroid's trajectory change, that sort of stuff. The first step in our plan needs to be to find out what kind of weapons/tactics/tricks/gizmos will actually work to divert or destroy an incoming threat, and the nature of the countermeasure that actually works will probably have considerable impact on the nature of the orbital platform that deploys it.

There will be a minor problem with that treaty somewhere that forbids nuclear bombs in space, to which I say tough knickers.

[Albert VDS]

This is actually some the United Nations should do, because after all it's something which affects us all.

[Scotius]

1 hour ago, WedgeAntilles said:

Actually, even before we do this, there's something else we should do first, and we already have the technology to do it.

What we should do is stick a few nuclear bombs on a remote-controlled spacecraft--some of the warheads being mounted on missiles, the others on robotic landing pods--then fly the ship out to an asteroid and test-fire the warheads against it to observe the effects. How much damage is done, how much does the asteroid's trajectory change, that sort of stuff. The first step in our plan needs to be to find out what kind of weapons/tactics/tricks/gizmos will actually work to divert or destroy an incoming threat, and the nature of the countermeasure that actually works will probably have considerable impact on the nature of the orbital platform that deploys it.

There will be a minor problem with that treaty somewhere that forbids nuclear bombs in space, to which I say tough knickers.

Won't happen until something big punches through the atmosphere, and flattens a city. Or at least a hundred square kilometers of habitated area. Only then everyone will wake up and get off their bottoms. And it will happen eventually. Our good luck will run out - it's inevitable.

[fredinno]

1 hour ago, WedgeAntilles said:

Actually, even before we do this, there's something else we should do first, and we already have the technology to do it.

What we should do is stick a few nuclear bombs on a remote-controlled spacecraft--some of the warheads being mounted on missiles, the others on robotic landing pods--then fly the ship out to an asteroid and test-fire the warheads against it to observe the effects. How much damage is done, how much does the asteroid's trajectory change, that sort of stuff. The first step in our plan needs to be to find out what kind of weapons/tactics/tricks/gizmos will actually work to divert or destroy an incoming threat, and the nature of the countermeasure that actually works will probably have considerable impact on the nature of the orbital platform that deploys it.

There will be a minor problem with that treaty somewhere that forbids nuclear bombs in space, to which I say tough knickers.

Wouldn't a normal impactor, or a gravity tractor be enough for most? I doubt putting warheads on a civilian rocket will be popular...

[Nikolai]

38 minutes ago, fredinno said:

Wouldn't a normal impactor, or a gravity tractor be enough for most? I doubt putting warheads on a civilian rocket will be popular...

A "normal impactor" won't work if the PHA is a loose rubble pile.  (It might be worthwhile to note here that the Deep Impact mission deflected Tempel 1 a lot less than we were expecting.)  And a "gravity tractor" works sluggishly enough that the area under threat would slowly be dragged across the borders of several different sovereign nations, each of which would be in a position to raise a stink if they so desired.

Deflection isn't an easy problem.

[GeneralVeers]

2 hours ago, Scotius said:

Won't happen until something big punches through the atmosphere, and flattens a city. Or at least a hundred square kilometers of habitated area. Only then everyone will wake up and get off their bottoms. And it will happen eventually. Our good luck will run out - it's inevitable.

Irrelevant. My point holds true no matter when we decide to build an anti-asteroid system (if that happens to be after an asteroid hits Earth somewhere, so be it). When we do build one, we need to do tests to find out what will actually work.

 

2 hours ago, fredinno said:

Wouldn't a normal impactor, or a gravity tractor be enough for most? I doubt putting warheads on a civilian rocket will be popular...

Depends if they work or not. Based on Nikolai's testimony vis a vis Deep Impact, I'm leaning towards "no". In any case, we should still do tests with nuclear bombs to see what effects they have on asteroids, if any. That's the kind of thing you want to know before an asteroid hits Earth, rather than after.

[fredinno]

47 minutes ago, WedgeAntilles said:

Irrelevant. My point holds true no matter when we decide to build an anti-asteroid system (if that happens to be after an asteroid hits Earth somewhere, so be it). When we do build one, we need to do tests to find out what will actually work.

 

Depends if they work or not. Based on Nikolai's testimony vis a vis Deep Impact, I'm leaning towards "no". In any case, we should still do tests with nuclear bombs to see what effects they have on asteroids, if any. That's the kind of thing you want to know before an asteroid hits Earth, rather than after.

The thing is though, Deep Impact's impactor was tiny-100 kg.

[RainDreamer]

Can we, instead of using a bomb, use lasers to nudge those asteroid away very early in its trajectory? Like send some satellite to orbit it, then use laser ablation to redirect it, little by little? Or maybe even attach some ion drives to it KSP style.

[Temstar]

@WedgeAntilles, you know, I never thought about it that way but you're right, since nuclear pulse propulsion is still the golden standard for high thrust high Isp we should probably practice it just to have some data on how it will work, when the time does come to save Earth you can't just send Bruce Willis.

Politically it's not workable, and not just because of Partial Test Ban Treaty. If the US came out and said "we're getting NASA to launch a hydrogen bomb on top of a Delta-IV Heavy to nuke an asteroid so we know what will happen", how do other country know this isn't actually a disguise for a Fractional Orbital Bombardment System that's a prelude to a first strike?

Or alternatively, if you say you're developing this technology to learn how to deflect asteroids away from earth, then by the same token the same technology would also allow you to replace the word "away" with "towards" and "earth" with "the Kremlin".

[Spaceception]

I just remembered PBS Space Time did a video about how to stop a killer Asteroid, enjoy:D https://www.youtube.com/watch?v=dEIjKjIgCA0

[Shpaget]

2 hours ago, Temstar said:

If the US came out and said "we're getting NASA to launch a hydrogen bomb on top of a Delta-IV Heavy to nuke an asteroid so we know what will happen", how do other country know this isn't actually a disguise for a Fractional Orbital Bombardment System that's a prelude to a first strike?

The same way you know that some of the countless military satellites already in space aren't armed. You don't know. You can only place trust, hope and silently do it yourself, just in case.

Anyway, without a very accurate trajectory prediction over long periods, there is little hope we can do anything. To achieve such accurate predictions, we need space based telescopes, and not just in LEO, but in solar orbit, and preferably inclined.

[SomeGuy123]

I'm amused by the posters saying it would be a waste of money.

If an asteroid on a collision course could be found soon enough - a few years lead - and the predicted damage was enough - you would expect a Total Effort - something last seen in ww2.  In practical terms, if there was total effort - everyone in the USA, the EU, China, and Japan all were investing everything they had into it - you could basically from scratch probably develop and deploy orion drive, fusion drive, build thousands of saturn V scale rockets - in about 5 years.  It would be a parallel effort - 50 separate projects at the same time, and each project would be run like the Manhattan project, where whenever there is uncertainty as to which approach to use, you just pay to use all the approaches.  

 

 

Edited January 11, 2016 by SomeGuy123

[Matuchkin]

I'm quite sure we can do something about the smaller asteroids, but we can not do anything for the average-sized ones in the next 25 years. Protecting ourselves from a Los Angeles sized rock is not quite possible.

Edited January 11, 2016 by 073198681

[YNM]

Let's stick some IR - NIR telescope in Venus - Sun L2. That'd worth a lot (in conjunction with Venus - Sun L1 for studying the sun, both act as relay to each other). Keppler telescope limped off, guess we can do better this time ?

[SomeGuy123]

46 minutes ago, 073198681 said:

I'm quite sure we can do something about the smaller asteroids, but we can not do anything for the average-sized ones in the next 25 years. Protecting ourselves from a Los Angeles sized rock is not quite possible.

If we know it's coming, and we have 5-10 years of warning, and all the wealthy nations know they can either

a.  Invest everything they have into developing the technology and constructing the Spacecraft to deal with it

b.  Risk extinction

Then you'd see an effort that has never been seen.  More progress could be made for space technology in 5-10 years than was made in the previous 50 years previously.

I mean, obviously, the simplest thing to do would be to make a fleet of Orion drive craft - just tear up the environmental regs and launch them right from the ground in a remote area.  You'd get the fissionables for the bombs by tearing the cores out of the current nuclear arsenals and remanufacturing them (after building and testing a variety of optimized designs for the bombs)

You then just dock the orion drive pusher plate with the asteroid, probably just 1 out of the fleet of craft, and then start exploding bombs.  A few thousand flashes later and the problem's solved and humanity can go back to disliking each other.

[Nikolai]

15 hours ago, fredinno said:

The thing is though, Deep Impact's impactor was tiny-100 kg.

Right.  Deep Impact's impactor delivered some 2e10 joules (20 gigajoules) of energy (around five tons of TNT), being a 370 kg impactor moving at 10.2 km/s relative to Tempel 1 at impact.

The amount of deflection, though, was only about 0.0001 mm/s (1e-7 m/s).  For a comet massing 7.2e13 to 7.9e13 kg, this corresponds to a change in Tempel 1's kinetic energy of 0.36 to 0.40 joules.

The fact that the impactor was tiny does not alter the fact that the deflection of Tempel 1 was rather smaller than we might expect given the conditions of the impact.

Edited January 11, 2016 by Nikolai
Changed "a little over" to "around", which is more accurate