Deep Impact scenario

[hongi]

What if the circumstances of the movie happened today? We find an 11km wide asteroid that will hit the Earth in say, 5 years (in the movie, there was 1 year between the discovery and the arrival of the asteroid). Is there anything we can do to deflect or destroy it?

[NecronLord]

The one in Deep Impact was supposed to be a comet. And realistically, no, probably not. At least, not in secret, like that.

[Temujin]

We certainly have some ideas on how to do it, but even with five years I'm not sure we could collectively get our asses in gear to actually stop it.

Even if it was just an asteroid, I actually would have more faith in the Russians actually being able to get something together in an attempt to stop it than the US. In the face of the Gulf disaster I no longer have much faith in the US to do much of anything in the face of disaster but resort to partisan infighting and finger pointing.

[NecronLord]

We certainly have some ideas on how to do it, but even with five years I'm not sure we could collectively get our asses in gear to actually stop it.

Even if it was just an asteroid, I actually would have more faith in the Russians actually being able to get something together in an attempt to stop it than the US. In the face of the Gulf disaster I no longer have much faith in the US to do much of anything in the face of disaster but resort to partisan infighting and finger pointing.

In fairness, in Deep Impact, the ship was supposed to be a US-Russian Orion Drive vessel.

[Srelex]

If space agencies work hard enough, I guess, we could divert it a bit by slamming an object into it, like NASA did with that comet a while back.

[Temujin]

We certainly have some ideas on how to do it, but even with five years I'm not sure we could collectively get our asses in gear to actually stop it.

Even if it was just an asteroid, I actually would have more faith in the Russians actually being able to get something together in an attempt to stop it than the US. In the face of the Gulf disaster I no longer have much faith in the US to do much of anything in the face of disaster but resort to partisan infighting and finger pointing.

In fairness, in Deep Impact, the ship was supposed to be a US-Russian Orion Drive vessel.

You know I forgot that that was actually a joint mission. I guess I remember the Russians from Armageddon better thanks to how horribly they depicted them/him (forgot how many there were, at least one on the actual mission).

[Srelex]

You know I forgot that that was actually a joint mission. I guess I remember the Russians from Armageddon better thanks to how horribly they depicted them/him (forgot how many there were, at least one on the actual mission).

There was one, played by Peter Stomare. Like much of the movie, his presentation was hilariously bad.

"THIS IS HOW VE FIX THEENGS ON RUSSIAN SPACE STATION!"

[cosmicalstorm]

I doubt it would be diverted. And I'm pretty sure that there would be vocal groups from all around the world who would either deny it existed, believe it was the will of god that it hit or believe that god would protect them from it.

[hongi]

If we don't manage to stop it, how would we fare? It's about the size of the one that caused the KT extinction event.

[Eternal_Freedom]

Yeah, you would probably get at least five different religous groups or cults saying it was the Hammer of God come to destroy the wicked, and an equal number saying it was a test of faith and we should do nothing to stop it.

Fortunately, they would most likely be ignored by the US, the Russians and maybe the Chinese and Japanese working to shift it, or blow it up, or deflect it or something

Heck, maybe they could shift it into a stable Earth ornit and strip-mine it

[Temujin]

If we don't manage to stop it, how would we fare? It's about the size of the one that caused the KT extinction event.

If we managed to survive at all it would probably be at a very reduced level of civilization, probably Iron Age at best.

[CaptainChewbacca]

Fortunately, they would most likely be ignored by the US, the Russians and maybe the Chinese and Japanese working to shift it, or blow it up, or deflect it or something

Heck, maybe they could shift it into a stable Earth ornit and strip-mine it

Shift it into a stable orbit? That's gonna require orders of magnitude more energy than a simple deflection or fracturing. It's not possible with our current level of technology.

[Sky Captain]

It might be possible to deflect it to slightly different orbit that misses with multiple standoff nuclear explosions. It really depends of how many nuclear bombs are needed to alter the orbit of impactor and how many rockets needed to deliver the bombs. Quickly available rockets might be a limiting factor because it would take time to seriously increase the production rate of rockets. Also the earlier the deflection operation starts higher the chance of success.

[Havok]

I honestly find it ludicrous that the public would not be warned that this was coming and would be kept a secret. We have seen how countries can unify and industrialize to meet a challenge. Imagine if the entire world was able to come together to save itself in this fashion.

[Srelex]

On a related note, isn't there a nutjob conspiracy theory that the Deep Impact space mission in 2005 was a cover for NASA diverting the course of a killer comet? Yeah, I know, but I was wondering if anyone else had heard this notion.

[starslayer]

Five years, huh? That's a tall order, to say the least. In any case, the solution is going to involve lots and lots of nukes (it's the only solution we can whip up on such short notice), either detonated on the surface or standing off a little ways (I don't know what the most effective distance for a good push would be). Even so, it may not be possible to intercept early enough, as we would need to build the interceptor, ready the nukes, launch, and get it into position, which could take a year or two all by itself. Assuming it is possible to divert it (attempting to fracture it is a Bad Idea), the nukes would be detonated against one side of the asteroid, one after another, vaporizing part of the surface and generating a small thrust. It should hopefully then miss the Earth, and go on its merry way, though we may have to deal with it again in the future. In any case, massive celebrations!

If it's not interceptable, and even if it is, massive civil defense style projects would be going on all over the world, building underground shelters to house as many people and as much industry and agriculture as possible. These shelters would be a couple meters underground (you don't need more cover than this, it turns out), and would have to be well stocked; they may have to hold out as much as two years, or provide transportation to warmer climes. The public would find out, whether the government wanted them to or not; remember the Glomar Explorer?

Assuming we don't manage to intercept it or deflect it enough, everything for several thousand miles around the impact site is going to come down with a bad case of death, whether due to the earthquake, thermal pulse, air blast, or - if it's an ocean impact - the gigantic tsunamis. The ejecta from the impact comes down all over the world; the heat released by all of this burning up on reentry serves to heat large portions of the atmosphere to incandescence, creating conditions not unlike those on the Venusian surface for a short time; this is why the shelters were built all over the world, because almost no one not underground or in a sturdy building of some sort (with plenty of cool, life-saving water) is going to survive this. After several hours, this passes, and the dust thrown up by the blast spreads out around the world, severely diminishing the amount of sunlight reaching the surface. Most of this dust falls out after a year or two, and then begins the long task of rebuilding.

Humanity would almost certainly survive such an impact; even a semblance of industrial civilization could be rebuilt in a relatively short time with enough preparation, I would wager. During the first few years following the impact, the world would be much colder than normal, with glaciers and heavy snowfall probably extending over most of the world, but the climate in fact soon returns to normal (IIRC, probably a decade or two at most). Even so, billions of us are going to die, whether from the immediate blast or from starvation and disease after the fact.

[Eternal_Freedom]

Hmmm. Massive civil defence projects. the Ark from "Deep Impact" springs to mind. And I agree, it makes no sense to keep this quiet.

Incidentally, that was one of my bigger objections to that damn 2012 film. They didn't tell anbody. Retards

[Cykeisme]

What would the best way to detonate a nuclear warhead to get maximum diversion in the path of a comet?
Would it be better to bury it slightly under the surface to maximize the mass of ejecta that is thrown outward to get a proper reactive push in the opposite direction?
Would a "shaped charge" detonation like those mentioned on Atomic Rocket work better? The directed radiation would bore a hole into the surface, I think, and generate a jet of ejecta almost entirely directed perpendicular to the surface, right?

Keeping it a secret from the public.. hmm.. I guess they didn't want everyone to panic, or worse, start acting in completely uninhibited ways without fearing the consquences since the world was ending.

[Caiaphas]

Would it be better to bury it slightly under the surface to maximize the mass of ejecta that is thrown outward to get a proper reactive push in the opposite direction?

I'm no scientist, engineer, physicist, or whatnot, but I'm guessing that managing to bury a nuke within a comet remotely is going to be a difficult proposition. I mean, you gotta put a drill or something on the top of the nuke, plus a power supply--that's going to be a good deal of extra weight that could be replaced with propellant--and then you have to deal with the cracks that could potentially occur. I mean, you set off a nuke within a big chunk of ice and rock, there's going to be shockwaves aplenty. I think.

Keeping it a secret from the public.. hmm.. I guess they didn't want everyone to panic, or worse, start acting in completely uninhibited ways without fearing the consquences since the world was ending.

Agreed. I bet when November 2012 swings around, we're going to see a huge spike in crime and other crap like that.

As to fracturing, how small would you have to get a piece of comet so that it would burn up harmlessly in the atmosphere?

everything for several thousand miles around the impact site is going to come down with a bad case of death, whether due to

Does it make me a horrible person if I laughed at the bolded part?

On a related note, isn't there a nutjob conspiracy theory that the Deep Impact space mission in 2005 was a cover for NASA diverting the course of a killer comet? Yeah, I know, but I was wondering if anyone else had heard this notion.

Nope. In any case, the impactor was 370 kilos, going 10.3 km/sec at impact, against a 7.5e13 kilo comet. It's like a fly headbutting a sequoia.

[Havok]

Incidentally, that was one of my bigger objections to that damn 2012 film. They didn't tell anbody. Retards

This I could see a little more. This is basically the planet changing completely with absolutely no way to stop it. No amount of work is going to stop what is going to happen. The reasons that they don't tell people in Armageddon and Deep Impact actually seem plausible as reasons in 2012. Civil unrest, lawlessness... basically chaos.
I mean I suppose you could put the world to work building Arks, but the idea of evacuating every country to China or where ever else they could and where the Arks could work, seems like a logistical nightmare and just completely impractical.

[adam_grif]

I'm agreeing with whoever said the nuclear shaped charge thing. ~85% of the energy put into a 22.5 degree cone of white hot plasma death, that's a substantial improvement over a regular nuclear burst that can hope for 50% of it's energy going towards the target at best.

The earlier a mission is launched against it, the better the chances of success will be, by virtue of smaller changes having bigger impact over a longer period of time. If necessary, multiple missions can be launched, one as soon as possible, and then increasingly mass-intensive ones as it gets closer and closer (easier to send more cargo at it if the target is closer).

Five years is, as others have said, a tall order. We didn't get to the Moon overnight, and that was back in the days when NASA had a respectable budget. Of course, near-unlimited funding by virtue of near-extinction being the alternative will no doubt expadite the process. Such an event is likely to spurr innovation in the field of "getting heavy things into the sky". Big-ass unmanned orion boosters are very promising in the short-term.

Oh god, I'm thinking about a supermassive US-Russian Orion battleship deflecting an asteroid. Somebody stop be before I start masturbating.

[starslayer]

If we want to have a hope in hell of stopping this thing, we need to get the deflector into orbit and on its way as soon as physically possible. This means current heavy lift rockets only, we don't have time to develop new ones. So Orion spacecraft, cool as they are, won't be on the agenda. As for funding, it's going to be a case of "what NASA/ESA/РКА wants, NASA/ESA/РКА gets," with straight up seizure of the required assets if the money doesn't talk enough. I agree, though, that multiple missions might be the best way to go, if and only if we have the personnel and facilities on hand (we don't have time to build new ones, remember!). If not, we will have to make do with one.

I didn't know about the possibility of nuclear shaped charges; if we can make them reliable, they would undoubtedly be the best choice to try and deflect the asteroid's path. Setting it off within the asteroid is not the best choice, but this has more to do with the fact that you waste a lot of the energy than anything else; it is also possible to fracture an asteroid of this size doing so if it has the right composition, something we don't want happening, as that would create the solar system's biggest shotgun, with it all coming straight for us.

[adam_grif]

I agree that the first mission(s) need to be with existing heavy lift systems. But the later ones can be an orion-craft

The nuclear shaped charge is what is used for propulsion on the Orion craft. So if we have shaped charges, we have the Orion-drive ready, and it's just a matter of physically constructing the body of the Orion. Of course we don't detonate it inside the asteroid or anything silly like that, instead we park the Orioncraft next to the asteroid, flip it around, and start dumping the magazine of propulsion charges, but this time they're rigged to explode facing the asteroid, instead of the pusher plate. That we also ablate the surface of the asteroid somewhat by doing this is a good thing.

[Srelex]

I thought Orion had been discredited as a viable system?

[adam_grif]

I haven't heard anything like that. Source?

From what I can gather, it breaks down as follows:

++ High thrust (good for launching cargo into space especially).
++ High delta vee compared to chemical rockets.
+ Relatively compact fuel/remass for drive (nuclear fission > igniting chemicals).

- Thrust comes in waves of high-G followed by no-G (bad for passengers).
-- Radiation must be dealt with.
- Public complains about nuclear anything.

Even if radiation / vomit inducing acceleration issues make it infeasible for a crew of squishy humans, it may still be viable as a heavy launcher and for unmanned missions.