I’ve been having a discussion with a pen pal of mine.
He has proposed the idea that a nation could protect itself from spy satillites by blinding their cameras with a laser whenever they pass over a sensative area(missle sites, navy bases, etc).
Hypothecially, it sounds like it could be done, though I think it would be a lot harder to do then he believes. It seems like you’d have to hit an awfully small target on an already rather small moving target and keep it on there for something akin to several minutes. I think if you were going to all the trouble with the laser, might as well just shoot down the satillite.
I’d guess it would be impossible as of now, unless you could track the satellite by sorta hacking into the satellite to find out exactly where it was. Not only this but the actual targetting of it is gonna be hard. If you had a laser shooting up at it, even the slightest vibration could knock the laser a tiny degree off of it, and miss the satellite. Also, even if you have all this, you still gotta deal with things like air distortion/clouds
I suspect it would be nearly impossible. As Ryle Dup said, you’d need to know with a fair degree of precision the orbital parameters of the satellite(s). Although I’m sure most governments have ways of obtaining such data even about secret spy satellites, it would take little effort on the part of the satellite’s operating country to adjust the orbit enough to throw this countermeasure off.
Indeed, and then you have the problem of getting the laser through the atmosphere. Various atmospheric effects will scatter the light emitted by the laser, and the end result would be a not very focussed beam at all. It would, therefore, be useless in ‘blinding’ a laser.
And then of course, if the position of the satellite is always known, and at certain points the satellite is blinded, causing a loss of coverage, then its going to be pretty darned easy to work out that there’s something there that your enemies don’t want you to see.
Call me naive, but assuming you could detect and track an satellite, wouldn’t it then just be a matter of advanced mathematics (Calculus and Geometry) and orbital phyiscs to plot the orbit of the satellitle to a fairly close approxmation?
Some US survellance satellites are in orbits only a few hundred miles high, and thus may be within the range of less powerful lasers, such as the Airborne laser, or the similar ground based theatre defense laser we’ve given to the Israelis.
Well firstly, many countries are capable of tracking satellites. 2ndly, lasing satellites has been done, and with a laser that’s 30 years old. I was trying to find an article (from space.com, I thought) I remember reading that documented damage to a satellite, and the concerns that this violated several international treaties, but someone else’ll have to look that up.
You’ve also got to contend with the satellite’s optics. Effectively, what the satellite will “see” is a normal landscape going by beneath it, but with one spot exceptionally bright. If it’s bright enough, that spot could burn out a line across the satellite’s sensor (presumably a CCD), but it couldn’t burn out the whole thing in one pass.
I’m not so sure of that. If the optics were ideal, then yes, you’d be completely correct. However, diffraction and reflection effects act to “smear” out light entering the camera with real-world optics. Under normal lighting conditions, the result of these effects is negligible, but with a powerful enough light source, such as a powerful laser, it becomes more significant. See what happens when a buddy shines a laser pointer at your camcorder’s lens from a distance while taping.
A big telephoto like on a spy bird would reflect light, like a cat’s eyes in the dark. If the vague location of the sat is known, it can be pinpointed by reflecting laser light off it and then shooting it with your 1920’s style death ray, or just a big laser.
Well, if a laser won’t work, why not a thousand massively-powerful floodlights pionted straight up over the area to protect? I mean, sure, that’s kinda like a big neon sign saying “hey, something cool and super-secret down here!”, but as for getting any details, try again, right?
The satellite builders have anticipated the possibility for some time now of lasers hitting satellites. Shutters can be closed to protect the detector elements. You’d probably lose a couple before you realised what was up but after that you know just where to look for the origin of the laser.
They were at least thinking about it. And adaptive optics in reverse might helpful in maintaining focus for regular lasers. Another SDI technology that’s now used by astronomers for viewing through a turbulant atmosphere.
But, the strategy of blinding a satellite over a certain target seems foolish. Better to put it out of commission in a seemingly random location. Or…, be more stealthy in the first place.
If I was only able to see your site from one satellite, and you could always know exactly when I was looking at your location with that one satellite, then you could possibly make it impossible to see it for a few seconds, once or twice before I figured out what you were doing.
Other than that, you would have to actually disable my satellite with your laser. I might notice that. I might consider it to be an act of war. Or, I might just send every diplomat from your country back home for his parking tickets. But I would almost certainly task every satellite in my inventory, not to mention other types of assets to investigate that particular site. Thanks for the tip.
It would be much easier to build something interesting and offensive on the site first, so I would get used to watching, and knowing what I was seeing. Then you could start doing something else offensive there, and I would not notice.