Steps to an earthbound humanity

How hard would it be to lock humanity in Earth forever under a cloak of space debris that prevents all space flight?

LEO would do, even if it lasts only a few years, it would be devastating enough for our telecomm-depending way of life, I think.

Is this a goal that the Taliban could reach? Bill Gates? China?

It would be impossible if the entire current resources of humanity were devoted to it. I don’t think I’m going to worry too much about it.

Upon further consideration, Iran and North Korea have solid rocketry backgrounds and no real perspective for a future space program (and would benefit more from darkness than, say, China). Are they anywhere near to being capable of doing such a thing to the rest of humanity? How many launches would it take? Are the powers that be giving this idea any thought?

I’m wondering if a modified form of a Berserker probe wouldn’t work: a nanotech space fighter that attacks anything in outer space moving under its own power and self-replicates. To destroy them you’d have to launch enough stuff to take them all out at once, and there’s always more, more. But probably never enough to blot out the entire sun, thankfully.

I think the concern exists that, even without ill intention, we are headed that way. Space debris is a real threat to astronauts and equipment up in space.

A quick search turned out this excellent NYT article:

(as usual, be quick before it goes pay-only)

They speak about a potential chain reaction where debris hits equipment and in turn produces more debris which… you know.

I am guessing it is easier to launch your own space frag grenades than trying to hit orbiting satellites. Sounds like a fairly basic project even for a country without a serious space prgram.

Dagnabit, there was a link to some calculations on how much sand would be needed to destroy orbiting satellites in this thread, but the thread with the calcs has disappeared.
IIRC, the result was a large number, but not undoable, if you’re willing to spend a hundred billion or so. That’s for a temporary barrier in LEO.

Well, it’s impossible.

Let’s say your debris field is at the top of the atmosphere, that’s a debris field with a surface area of 706 million square kilometers. (surface area=4 pi r squared, radius of earth is roughly 6500 km, plus another 1000 km of atmopshere). Or put another way, a one foot thick debris field would have to be – 7,608,553,985,304,428.4 cubic feet There ain;t that much matter on earth, unless you blow up the planet itself.

There are some other even bigger problems. First, the gravitational field of the earth would prevent any planet-covering field from staying in place, and the further out you put it, the bigger it would get.

Then there is the practical problem of transporting your debris field from one place to another, and the fact that after you have covered the entire planet, all that’s needed to break free is one small hole…

You want to hamper telecommunications – a few well placed pulse weapons would do the trick.

I beleive that the need to depend on satelites for communication may be coming to end with the advent of high altitude ballon stations and laser linked communications. I think that I saw this on the Discovery channel last week on a series about technology in the year 2057. Pretty neat show.

Space is an awfully big place. Could you block transatalntic travel with a debris field (or anything else)? Even if we limit it to surface traffic, I doubt it, and that’s an exponentially smaller problem.

I’m not convinced you even block air travel over a major city.

But you don’t have to interdict that whole area. Satellites go around the earth. So if you create a ring of debris which also goes around the earth, a satellite will intersect it twice on each orbit. That fact reduces considerably the amount of material you need to make LEO untenable.

These probes would need to collect raw materials in orbit in order to self-replicate. And if there’s that much junk in Earth orbit, you don’t need the probes.

Well, some US scientists have proposed blotting out the sun to stop global warming. cite.

Seems reasonable to enough me, not like all that gay-ass shit about cutting emissions, reducing consumption of fossil fuels, and developing alternative fuel sources.

I think you misunderstand the problem. You don’t need to cover the entire surface of the planet; you just need to intersect every low-Earth orbit, which is much, much easier. Just put a relatively small cloud of stuff up, in a retrograde orbit: Eventually, everything else in low-Earth orbit will hit that debris cloud, at very high relative speed. Punching “one small hole” through won’t solve anything, since everything up there is always moving, and therefore won’t stay in the safe hole.

If you’re trying to stop satellites, the field you propose won’t do much at all; most of our low-earth-orbit satellites are between 500-1000 km. You could put a 500kg satellite in a retrograde orbit and have it fire little 1g ball bearings laterally at 5 m/s every minute or so, and that would give you a few thousand particles sweeping through one orbital band. If you could carry 100kg of ball bearings (100,000 1g projectiles), they would be spaced 300m apart but would cover two 15,000 km-wide swaths. Their forward motion would very quickly make them intersect lots of orbits, and atmospheric randomness would pull some of them to lower altitudes before they decayed and reentered. For bonus points, pack 1kg of explosive on board and blow up the satellite when you’re done.

Couldn’t you just launch your satellites in retrograde orbit along the same path as the debris?

Seriously, how many flights would you need to make even a significant number of orbital paths unviable? How many gaps would have to made impossible to aim for to get satellites above the cloud? How would the offending nation do this with their launch pad blown to component atoms?

It’s not going to happen, except possibly in a movie starring Bruce Willis.

What **Chronos ** said. You don’t need to roof the whole planet (cool as that might sound). The link I provided shows the debris left by the recent Chinese anti-satellite test. A veritable band of shrapnel. This one happens to be in a fairly high orbit so it shouldn’t be too too troublesome for most of our telecomm satellites.

Still, making a serious mess sounds like a fairly simple project. A handfull of rockets to LEO packed with nuts and bolts and a small explosive charge is all it would take. My GQ is, are there any missiles out there (in the hands of baddies, of course) that could be repurposed to just go up to LEO with such a payload? How many of these launches would it take to turn LEO into a mosh pit (it doesn’t have to be instantaneous, if it takes a few years, it is still enough).

I’m too lazy to figure out hom many rockets full of ball bearings would do the trick, but here’s some related photos I found:

You misunderstand (atypically, for you) – ball bearings or some other small (but big-enough-to-be-lethal) debris won’t have a single well-defined orbit that you can go aklong the path of. You’ll very qyuickly get criss-crossing orbits of unpredictable particles moving at very rapid velocities. They’re not going to stay in an equatorial orbit, if you release them right – you can easily cover a large portion of northern and southern latitudes as well. Covering the poles would be more diffilcult, unless you launched from near there. The point wouldn’t be to deny space-travelling nations all access to space, but to make it a great deal more dangerous. Keeping track of a vastly increased "threat clioud’ of orbiting random debris becomes more difficult and more prone to error as the number of bits goes up (and increses the likeliness of colliding with other junk up there, randomizing orbits and onjects still further.
Can you make a effective shield? It depends upon the level of risk that will deter the people who want to launch through that debris field.
The son of Daniel O. Graham, proponent of the “High Frontier” space-based weapons concept (that was one of the sourcers of reagan’s support for SDI) wrote a science fiction novel about this – ]B]The Gatekeepers**. Certainly they believed it was a possibility.

Right now, a weather satellite needs to be on-orbit for 7+ years to be considered a success. If you can put a debris band near the most useful polar orbit altitudes, you can cost the U.S. a lot more money – either we’ll build a backup satellite or we’ll spend hundreds of thousands of engineering dollars on debris tracking sensors and orbit planning. I’ll get back to the idea of “useful” orbits in a moment.

As for “launch pad blown to component atoms,” China just performed an ASAT test and suffered no reprisals for it. That debris cloud was unpredictable when they created it and easy to get around for now, but it will serve to black out imagery over China once or twice a day for the next decade (because it denies anyone the use of those nearby orbits). Also, any ballistic missile that can go 3,000 km with a useful ballistic payload could probably also put an ASAT payload in low earth orbit, and for a relatively modern missile it would only require a guidance software change. It’s pretty common for countries to make MRBMs of that size road-mobile, so the “launch pad” is a truck that is 40 miles away by the time you can get anything on the original launch location. China, Russia, and (maybe not today, but definitely in the next decade) Iran have the capability to do satellite-denial with road-mobile MRBMs. I don’t think the U.S. maintains any road-mobile missiles, but we could start. :dubious:

The nasty property of the “cloud” is that it doesn’t really have an edge – there’s no way to be 100% sure that your satellite is above the cloud. You can put a satellite very high up and be pretty sure you’re safe, but for some missions (e.g. imagery satellites) you want an orbit that is very high at some points and very low at others. Not crossing the cloud isn’t really an option for those orbits, and eventually probability will catch up with them.

It’s true I didn’t at first understand the OP, but I think the way it was originally expressed was misleading at best and has shifted considerably.

My point is that if a nation acts in this way, it’s an act of war against the world. Much different from the Chinese blasting a satellite or SDI or any of the current means of disrupting free space travel.

Sapo, your talk of the baddies getting away with this for years is fictional. It could happen once. Neither China nor Russia nor Iran for that matter could live with the consequences of destroying intercontinental communications just to prevent spy satellites; they are all far too dependent on satellites themselves. Here’s a quote from your very own link:

Only true rogue non-nation-based terrorist groups have any incentive to do so, but that also means that they could have no support anywhere. This would result in a real coalition of nations to end their predation, and they could not survive that, no matter what scenarios you might want to conjure about mobile trucks out of North Korea or Taliban-controlled Afghanistan.

And one more quote from that article:

It’s easier to imagine international cooperation to remove debris from important orbits than it is to imagine space travel becoming nonviable.