Not that the article was incomplete, but I was expecting at least a passing reference to Kessler Syndrome.
(New Registration, I’ve lurked a while…)
Very interesting WIKI article. I hadn’t heard of Kessler Syndrome before.
I did prick my ears up at the end of Cece’s column though…
The Kessler article doesn’t seem to offer any suggestions and Cecil seems indicate that it will be just a matter of launching a broom and dustpan.
Are there any ideas so far in how to deal with the issue?
It’s a very long, complicated issue, since the size of some of the stuff is smaller than a fist. Even a grain of sand going at… well, orbital velocity can cause a lot of problems.
The best solution I’ve read is a very large electromagnetic field that deflects everything down into an orbit that would eventually lead to it entering (and burning up in) earth’s atmosphere. However, this wont work with non-magnetic items (plastics, for instance).
The simplest solution is to stop sending missiles into orbit to blow up defunct satellites (I’m looking at you US and China!) and for us to clean up after ourselves. Spending the extra cash to put boosters on our satellites that either push them into Earth’s Orbit our out into Space far enough that they completely leave it.
Simply pushing them into ‘junk orbit’ is not really sufficient, imo, because at some point we’ll want to use those orbits too, given enough time.
When you look at the US, are you thinking of last March’s shoot down of a crippled spy satellite? They made an attempt to minimize the time the debris would remain in orbit by waiting until it was at a low altitude. From that link
Contrast that with the Chinese event, which was simply irresponsible:
Missed the edit window. It was shot down in February. It would have come down in March on its own.
Yes, they minimized the debris.
That’s kind of like me choosing to beat someone up and then justifying it by saying “Oh, I minimized the permanent damage by only punching him in the ribs, so I wouldn’t hit any vital organs…” (or some such similar story)
Yes, well, I still committed assault.
The fact of the matter is that the public justification (that they were worried about hydrazine) was bullshit and they were looking to show 1) that they could do the same thing China could do, 2) that they could (theoretically) shoot ICBM’s down in their midcourse phase and 3) they didn’t want the tech falling on foreign soil.
It was political strutting most of all, and it was, quite frankly, reckless.
All of this could’ve (potentially) been avoided if the US would’ve spent the extra 10 or 20 thousand dollars for ten or twenty pounds of compressed air that could be released via radio-coded command and sent he satellite into a lower orbit in a controlled manner, and they could’ve predicted the re-entry, and had it re-enter either over the ocean or Sovereign US soil.
This, of course, assuming that the re-entry fail-safe wasn’t built to the same High Standards that the satellite itself was manufactured to.
Your analogy is flawed. There was at least plausibly a danger to people on the ground. Applying the Heimlich maneuver to someone would be a better analogy.
You don’t know this. Neither do I, but I know that anyone who actually did know wouldn’t be posting about it on a message board.
Maybe. Do you have cite for this?
I disagree. My point is that the Hydrazine isn’t a realistic concern. It’s a liquid held in a hollow container would most likely rupture high in the atmosphere.
Here is a list of its adverse health effects. Hydrazine is recommended to not go above the low PPM (for the sake of argument, we’re ascribe single digit), that would be to say that a hollow container of hydrazine made it, not only through re-entry into earths atmosphere, but survived an uncontrolled burn, and the massive turbulence associated with it, below about 10,000 feet (I think lower, but I’m being generous here).
IIRC there was less than a few gallons of Hydrazine on board.
Valid point, however granting my posit that the hydrazine (only for the sake of this specific part of the conversation) isn’t a realistic threat, what other assumptions would you make?
I’ve always ascribed very closely to the idea behind “The direct use of force is such a poor solution to any problem, it is generally employed only by small children and large nations.” (David Friedman)
In fact, large nations very often act like small children, “If you can do it, I CAN TOO!”
There’s no real cite for this, it’s a compilation of my knowledge about space and trajectories along with commonplace estimates on how much it takes to lift 1 pound into space (10,000 per pound).
They could measure the thrust that the compressed gas would have based on the size of the nozzle releasing the gas, the length and the duration of the gaseous discharge. They could then input that to the orbital trajectories to determine exactly when to turn the satellites thruster on, (say, over Georgia, so that it comes down off the coast of California).
I’d like to note that I’m not a crazy conspiracy theorist (or a conspiracy theorist of any kind), and that this doesn’t seem like that big of a deal, other than the fact that I see space a relatively pristine area which should be saved for future generations, and for ourselves, in fact. For every single object we put into orbit, we increase the odds (if only minutely) of a catastrophic failure of one of our manned missions.
That’s just the sort of thing a crazy conspiracy theorist would say.
Uncontrolled burn should be Uncontrolled reentry. Sorry, I missed the edit window.
I see what you did there!:dubious:
The US trys to mitigate threats to orbiting assets from space junk using this system:
http://www.fas.org/spp/military/program/nssrm/initiatives/navyss.htm
Apparently used to keep tabs on what everyone else has up there too…
So, is it a solution (or part of a solution) to have satellites launched with some type of scuttling routine? (A self-distruct sequence that would push them into re-entry?)
My impression thus far is that the Kessler Syndrome is mostly a result of collisions and other accidents rather than the accumulation of derelict satellites and rocket flotsam.
Most definitely, at least in my opinion.
You are correct, but if we continue to accumulate orbital debris, the chances of impacts go up exponentially.
Something as small as a baseball or a fist hitting an old, broken down satellite would create a situation where tens of thousands or new particles would be created, increasing the chances of these impacts happening again, and again, and again.
:smack:
Magnets. BIG magnets. 
What about for nonmagnetic debris?
Plastics, glass, etc
Hoover. BIG hoover.
Here’s another article on space debris.
Among other things, a huge aerogel blob has been suggested to absorb debris into itself.
So, what exactly is your “knowledge about space and trajectories”? Because what you’ve demonstrated here is little more than handwaving that is apparently based on a pop science understanding of spacecraft design and orbital mechanics.
First of all, most modern satellites and orbital space vehicles are designed to either eventually reenter the atmosphere at shallow angle that virtually guarantees breakup and virtual annihilation of the debris (satellites in Low Earth Orbit), or to attain a permanent parking orbit that is sufficient to prevent it from dropping to LEO on any reasonable time scale. Those with circular or near-circular LEOs are equipped with sufficient maneuvering reserve to effect a controlled deorbit maneuver. This is performed at the end of useful life. Adding another propulsion subsystem to perform this specific maneuver (which would include not only the mass of the propellant, but also all of the plumbing, valving, avionics, and nozzles) is not only cost prohibitive but also unnecessarily adds to the complexity and likelihood of failure. If communication and control is lost with the spacecraft, or if the space launch vehicle fails to place it in a functional orbit (as happened with the satellite that was shot down earlier this year) then an extra ten or twenty pounds of compressed air propellant isn’t going to make much difference one way or another. You’re certainly not going to achieve an Earth escape trajectory with that paltry amount of energy, so if you can’t build enough reserve into the stationkeeping system already onboard, adding another system isn’t going to get you there.
The satellite that was shot down by an SM-3, by the way, had an estimated 1,000 lbs of frozen hydrazine, and had failed to enter a sustainable and operable orbit. While I would tend to agree that the shootdown was as much a saber-rattling exercise as anything and that the risk posed was minimal, the fact is also that all of the debris from that impact reentered Earth atmosphere within a few weeks.
The majority of small debris in orbit isn’t actually satellites themselves (either whole or broken due to impact) but various bits of ordnance hardware and other loose pieces associated with the launch and orbital boost vehicles. In modern designs these objects are all designed to be captured, i.e. bolt cutters, separation rings, et cetera are all enclosed or tethered to prevent them from flying loose in undetectable small pieces. However, there is still debris from decades past that is still in orbit when orbital pollution was not considered, and this can both pose a danger and create more debris from impact with extant satellites. Separable pieces of modern space launch vehicles are designed to either reenter in toto (like the STS External Tank, which is released into an induced tumble which causes it to break apart and create a defined debris field over the Indian Ocean) or follow the spacecraft in a well-defined trailing orbit. Any object of sufficient size in a known orbit can be tracked and entered into a catalogue; NASA, ESA, and JAEA all maintain current catalogues of satellites and known orbital objects that are readily available.
There is still the danger associated with fragments of paint, insulation, et cetera that may come lose during launch and insertion. One of the Shuttles had the cockpit glass pitted by such an impact. There is also gear and trash ejected or launched during manned missions, and there was actually quite a bit of concern about John Glenn’s golf shot coming back around and hitting his spacecraft. There is little that can be done to prevent this type of debris other than minimize the amount free to come loose, and make certain that trash is either brought home or ejected with enough velocity to effect a deorbit.
All of the proposals I’ve seen for clearing orbital space of debris–including deploying silicone aerogel buffers, using lasers to target and slow debris, drag tethers, et cetera–are speculative and not ready for application. It’s one thing to make an artist’s rendition for next month’s Popular Science, but quite another to design, test, and deploy such devices in reality.
Stranger
Not exclusively based on Pop-Science… but I certainly do enjoy a good magazine when I see one. (Have they published anything other than Adds in that magazine in the last ten years, by the way?)
This, I was aware of. However, I’m not a fan (at all) of “Parking Orbit.” I think it’s simply putting the problem off for another day.
I was using a gross oversimplification, no argument there. There is absolutely no need for another system to be installed, on top of the maneuvering one.
Unless the Satellite is in an uncontrolled spin, it seems to me that a fail safe could be built into it, so that the entire thing could, automatically, re-enter earths atmosphere over <insert safe place here>. However, there would probably be the increased associated risk that this would go off accidentally, and that would be bad…
Yes, it was a gross oversimplification on my part, adding it to the maneuvering system would be far more efficient, without question.
Jeeze, was it that much? My bad.
All of them? If it was just saber rattling, any debris that didn’t reenter earth’s orbit are (in my opinion) irresponsibly fired projectiles in a currently uncrowded, but potentially (in the future) crowded room.
This is the type of stuff that I’d be most worried about when blowing satellites up in space, honestly.
Agreed, it’s all on the drawing board, and even the best we have now is unrealistic.
I’m still of the opinion, though that cleaning up after ourselves (and not making explosions in space, unless absolutely, 100%, no questions asked necessary) is the best solution. All the rest of it is speculation as to whether or not it’s even possible.
When a satellite is done, it should (imo) either re-enter earth’s orbit or achieve complete escape velocity. The latter is obviously extremely expensive and unrealistic, so the former seems like a much more reasonable solution (and the one I was attempting to advocate, not 10 pounds of propellant to give us escape velocity).