From what I can make out, the idea is that military satellites will circle the earth carrying big f*ck-off girders that can be propelled at enormous speed towards ground targets, which made me wonder…
If these rods are just flung earthwards without an onboard engine/propellant, how could they be usefully accurate from such a distance?
And if the speeds quoted are true, wouldn’t the recoil from firing them skew the satellite’s orbit badly?
How would they even achieve such huge speeds for the projectiles?
Apologies in advance if I’m missing the point here…
You’d have to accelerate them to that speed to get them into orbit in the first place. Give one a little nudge backwards, and all that stored up potential energy turns kinetic when the rod falls. The shape (long and thin) will help it slice through the atmosphere as quickly as possible, like a dart. Otherwise it would tumble due to air resistence, like an old Soviet space station.
It sure seems like a damn waste of rocket fuel; the only advantage I can see if that they’d be in orbit, ready do drop on anyone at any time, whereas something like a cruise missle takes time to set up.
I flatly don’t believe that they can be aimed with sufficient accuracy to take out Saddam’s bunker, as the article hypothesized. We have enough trouble with our airborne bombs falling on the wrong targets; imagine a misguided missile with the speed of a meteor.
Why? It would essentially be a smart bomb without the bomb part, and dropped from orbit instead of a plane. Do you not think a smart bomb could hit Saddam’s bunker?
We have a lot of problems with airborn bombs falling on the wrong targets? How much is ‘enough’?
I remember reading about this idea years ago. There was even a sci-fi novel that used it…Footfall, something like that. They called it Thor or some such, and they were basically flying guided crowbars that were used to take out enemy armor. I’m not sure how wise such a system would be, but it seems plausable that it could work…and it would probably be fairly efficient once you got them up there.
The Rod of God, when thou considereth it, dost thou say in the fastness of thy heart:
[ul]a) I exalt in the downfall of mine enemies?!?
b) Woe unto me, in my sinfullness!?
c) Yum yum! Good eats!?[/ul]
From the link in the OP:
“Jerry Pournelle, a science writer and chairman of the Citizens Advisory Council on National Space Policy, came up with the idea, which he originally named “Thor” after the Norse god of thunder. The Pentagon won’t say how far along the project, or variants of the idea, may be in development.”
The article is 3 years old so any day now someone is going to get a Tungsten Rod in their back garden. Let’s hope they deserve it.
It would take more than “a little nudge” to get them to drop. With a little nudge you get an orbital perturbation. If you wanna look to SF stories for confirmation, check out Arthur C. Clarke’s short story “Jupiter 5”.
The point is that, even if you cancel out the energy associated with the orbital velocity, you still have all that potential energy from the height above the earth’s surface, and you can get all that back, minus the energy lost to friction, as kinetic energy. This can make for one big boom on the ground.
I have no idea how accurately you could guide it – it would depend on exactly how the thing dropped. I could easily see you getting one of those MHD shockwaves that would reflect your radio sigtnals back (remember how the astronauts used to be out of radio contasct during a large part of re-entry), so you [ui]couldn’t* control your flight. Or the whole thing getting so hot that it’d disable any sensors and controls you had. But engineered properly, you could probably come up with something that had a pretty good chance of coming down in the general vicinity of where you wanted it.
Sorry Squink, Vetch…I didn’t read the link and I didn’t remember who the author of Footfall was…just remembered reading the book a few years ago. Was just working off the top of my head and winging it as I usually do. Didn’t mean to put in redundant stuff.
I’d have to see how they were planning on doing it, but hitting a particular bunker is no cakewalk even with highly sophisticated devices, I understand.
There is also a lot of leeway between “I have no idea how accurately you could guide it” (which is what CalMeacham…I read that as HE doesn’t have any idea how such a system would be guided) and saying its impossible to do. I am confident that if they actually deploy this as a weapons system that SOMEONE would have solved the engineering problems of guiding the weapon to target. I see no physical barriers to such guidance…just engineering to get it to work.
Almost true – I have no idea exactly how the existing plan does it, to overcome the possible problems I suggest. I can come up with some ways, but I’m not an aero/astro engineer, and I’m not sure if they’d work.
Terminal velocity of RVs from an ICBM generally get up around 25000 fps, and that with a relatively small tangential component. 12000 fps from an orbital platform actually sounds kind of low.
The other problem with cruise missles (several, actually), is that they are limited in range (~600 nmi); some Los Angeles class submarines and the Sea Wolf class can launch them from their VLS, boomers can launch them (in groups of seven) from their tubes, and they can of course be launched from most frigate and larger surface ships, but you have to have the vessels in position. An orbital platform, however, can drop anytime it is “overhead” (the launch envelope is more complicated than that, but with a constellation of satellites in a retrograde or ball of twine orbit you can ensure a launch window at most of the earth’s land surface inside of an hour)
Consider a lot of our difficulty in hitting particular targets isn’t the accuracy of the missile per se, but rather a difficulty in identifying the correct target visually. “Smart” bombs that are guided by a laser designator typically strike within feet of their designiated targets. ICBM RVs from Peacekeeper (control systems designed prior to 1985) have a CEP (circular error probability) of <90m, and are unguided after their release from the warhead bus stage (some claim the actual accuracy is measured in low double digit meters). A modern launch platform should be able to at least match if not vastly exceed that accuracy, not even accounting for active terminal guidance.
That being said, this would be a very expensive system to emplace, with no strategic value and of questionable tactical value. Yes, we’d be able to strike at a remote target without the logistical exercise of moving planes and support equipment or naval assets to within range, and the projectiles would be virtually unstoppable by any modern technology short of a HIBEX/Sprint-type nuclear tipped interceptor, but is the expense and maintainence of the system worth the (hopefully) occasional use of it? Permanent space-based platforms are difficult to defend against attack; at orbital velocities it doesn’t take much to damage a simple platform, as a shower of fragments a 0.5 m/s slower than the orbital speed of the weapons platform would be enough to put it out of operation. A high-altitude hypersonic platform, or a FOBS-type booster and RV would make a lot more sense, really, from a tactical point of view.
It also opens up orbital space as a battlefield from a political point of view. We’re already hard pressed to explain why other nations should not develop nuclear weapons when we maintain such a large stockpile ourselves; by sticking foot in this pond we’re opening up the arguement that other nations should, too, even if they’ve not the strategic necessity. Witness France and their pointless nuclear development and testing program. Put the two together (nukes and space) and its off to another, nastier Mexican stand-off between spacefaring nations, instead of committing to a non-military development of space.
But the article in the OP, despite the verbage implying that all of these options, including the penetrator rods are in some stage of development, is highly speculative. The DoD and SDIO/MDA are constantly funding blue-sky proposals for this sort of thing; most never make it past a feasibility stage, and even when the do, they often spend years or decades stalled in development while technical hurdles, internal politics, and treaty agreements halt or delay work on making an operational system. Things that seem like trivial issues–like who’s authorized by contract to do what work, or developing a C[sup]3[/sup]I system to integrate target discrimination and authorize launch–end up as stumbling blocks to system deployment. It’s easy to dream up this Tom Clancy-type stuff; it’s a lot more complicated to render it on the canvas of the physical world.
One concern with any of these space-based weapons, quite apart from the “Arms Race” implications, is the possibility of them being hacked.
Currently, the chance of an ICBM being launched from North Dakota (or a SLBM from a boomer) by an enemy, with the target being the US or one of its allies, is as close to zero as can reasonably be imagined. AFAIK, there is always a point where a human with a physical connection to the launch trigger (in a silo or sub) makes the decision based on received orders.
In an unmanned space-based weapons platform, the targeting and launch data will be sent remotely (presumably via radio if it’s a global system). So, however unlikely it may seem, the possibility of such a system raining death on the White House is several orders of magnitude greater than the possibility of terrorists launching a US ICBM or SLBM against a friendly target.
I know that the hacking of space-based systems has been the subject of popular fiction (Diamonds are Forever, Goldeneye, and Under Siege 2 all spring to mind), but it is a potential security hazard.
I think it’s more important to hope that the point – or sharp end of the rod or whatever – misses you! (Cue for someone to add an “In Soviet Russia…” joke).
