4 ms·

Lets get bunch of rails into the low polar orbit. Once a 1000 or so is deployed, there will be an almost-instant (20 minutes) strike capability for any location

by vl 16y ago

Lets get bunch of rails into the low polar orbit. Once a 1000 or so is deployed, there will be an almost-instant (20 minutes) strike capability for any location on the earth. The good part is that kinetic energy of re-entering rail will be unmatched by any railgun. On the serious note, they didn't specify the weight of the projectile, and this is quite important factor. Comparison of the energy delivered at the target range to the energy delivered by the conventional winged missile would be useful as well. Blog of the guy who build portable supersonic railgun at home (in Russian): http://railgun.org.ua/ http://railgun.org.ua/ Check out his video page: http://railgun.org.ua/video/ http://railgun.org.ua/video/

bigiain 16y ago
If you take the numbers from the article as accurate, 33 megejoules at Mach 7 means the weight is ~15kg (assuming I got all my conversions and orders of magnitude right, feel free to do your own e=1/2mv^2 calculation...)
- aidenn0 16y ago
  I got ~10kg from the 2500m/s number, and under 12kg from the Mach 7 number. Google agrees: http://www.google.com/search?q=2*33megajoules/(2500+m/s)^2+in+kg http://www.google.com/search?q=2*33megajoules/(2500+m/s)^2+i... http://www.google.com/search?q=2*33megajoules/(7+*+speed+of+sound)^2+in+kg http://www.google.com/search?q=2*33megajoules/(7+*+speed+of+...
- borism 16y ago
  Projectile speed will be much less after it has travelled 100km.
pak 16y ago
I don't think other world powers would be totally cool with us putting superweapons into low polar orbit right over their heads... you should totally expect those satellites to be shot down as soon as you put them up there.
- vl 16y ago
  Why would they shoot down relatively harmless rails from the orbit and not other already existing spy satellites?
  - borism 16y ago
    because of offensive vs. defensive purpose?
icegreentea 16y ago
You already have 20-30 minute strike capability for any location in world. You've had it for decades. What you want is 20 minute strike with less warning than existing ICBMs. And also banned. The nuclear weapons reduction and restriction of weaponization of space treaties are some of the successful treaties with regard to controlling weapons that anyone, let alone the United States has been involved with. Violating said treaty will bring ridicule and anger to whoever breaks it, and a non-miniscule chance of the other major nuclear powers launching all their nukes.
- smhinsey 16y ago
  As much as I would prefer otherwise, it seems pretty clear that space has already been weaponized. Between the Shuttle the X-37, and whatever else exists, for all we know there are already satellites in orbit armed with kinetic kill vehicles.
  - jerf 16y ago
    All satellites in orbit are already kinetic kill vehicles, just with varying degrees of sophistication. Everything in space is a kinetic kill vehicle. The idea that space can somehow not be weaponized is sheer physics ignorance. In some ways this is the largest challenge to space exploitation, which is rapidly becoming relevant as commercial spaceflight recently passed a milestone. A corporation that can retrieve an asteroid for mining purposes is a corporation that can drop that asteroid on your capital. There aren't very many realistic treatments of this scenario in "the literature". ("The Moon is a Harsh Mistress", at least the base scenario if not the details of the superintelligent computer, is one of the few.)
    - smhinsey 16y ago
      Maybe I shouldn't have used that term. I am aware of the basic physics of the situation, but that's not what I was talking about. I think it's likely there are already devices in orbit with the capability of launching "dumb" (i.e., non-explosive ) munitions to either take out other satellites or small targets on earth. When people discuss the weaponization of space in terms of the treaties, implying ignorance because it isn't about basic physics doesn't provide any constructive input, and is frankly just needlessly hostile. These treaties are about weapons in a military sense, with the ultimate issue being the presence of nuclear weapons in orbit. I don't think it would be news to anyone that the whole business is inherently dangerous and that anything in orbit can come down anywhere on earth with little warning.
zitterbewegung 16y ago
Yea except that inconvenient treaty that states you can't put weapons in space. Oh and also if you try to do this China would just try to shoot it down anyways. http://en.wikipedia.org/wiki/Outer_Space_Treaty http://en.wikipedia.org/wiki/Outer_Space_Treaty

by vl 16y ago

bigiain 16y ago

If you take the numbers from the article as accurate, 33 megejoules at Mach 7 means the weight is ~15kg (assuming I got all my conversions and orders of magnitude right, feel free to do your own e=1/2mv^2 calculation...)

aidenn0 16y ago
I got ~10kg from the 2500m/s number, and under 12kg from the Mach 7 number. Google agrees: http://www.google.com/search?q=2*33megajoules/(2500+m/s)^2+in+kg http://www.google.com/search?q=2*33megajoules/(2500+m/s)^2+i... http://www.google.com/search?q=2*33megajoules/(7+*+speed+of+sound)^2+in+kg http://www.google.com/search?q=2*33megajoules/(7+*+speed+of+...
borism 16y ago
Projectile speed will be much less after it has travelled 100km.

pak 16y ago

I don't think other world powers would be totally cool with us putting superweapons into low polar orbit right over their heads... you should totally expect those satellites to be shot down as soon as you put them up there.

vl 16y ago
Why would they shoot down relatively harmless rails from the orbit and not other already existing spy satellites?
- borism 16y ago
  because of offensive vs. defensive purpose?

icegreentea 16y ago

You already have 20-30 minute strike capability for any location in world. You've had it for decades. What you want is 20 minute strike with less warning than existing ICBMs. And also banned. The nuclear weapons reduction and restriction of weaponization of space treaties are some of the successful treaties with regard to controlling weapons that anyone, let alone the United States has been involved with. Violating said treaty will bring ridicule and anger to whoever breaks it, and a non-miniscule chance of the other major nuclear powers launching all their nukes.

smhinsey 16y ago
As much as I would prefer otherwise, it seems pretty clear that space has already been weaponized. Between the Shuttle the X-37, and whatever else exists, for all we know there are already satellites in orbit armed with kinetic kill vehicles.
- jerf 16y ago
  All satellites in orbit are already kinetic kill vehicles, just with varying degrees of sophistication. Everything in space is a kinetic kill vehicle. The idea that space can somehow not be weaponized is sheer physics ignorance. In some ways this is the largest challenge to space exploitation, which is rapidly becoming relevant as commercial spaceflight recently passed a milestone. A corporation that can retrieve an asteroid for mining purposes is a corporation that can drop that asteroid on your capital. There aren't very many realistic treatments of this scenario in "the literature". ("The Moon is a Harsh Mistress", at least the base scenario if not the details of the superintelligent computer, is one of the few.)
  - smhinsey 16y ago
    Maybe I shouldn't have used that term. I am aware of the basic physics of the situation, but that's not what I was talking about. I think it's likely there are already devices in orbit with the capability of launching "dumb" (i.e., non-explosive ) munitions to either take out other satellites or small targets on earth. When people discuss the weaponization of space in terms of the treaties, implying ignorance because it isn't about basic physics doesn't provide any constructive input, and is frankly just needlessly hostile. These treaties are about weapons in a military sense, with the ultimate issue being the presence of nuclear weapons in orbit. I don't think it would be news to anyone that the whole business is inherently dangerous and that anything in orbit can come down anywhere on earth with little warning.

zitterbewegung 16y ago

Yea except that inconvenient treaty that states you can't put weapons in space. Oh and also if you try to do this China would just try to shoot it down anyways. http://en.wikipedia.org/wiki/Outer_Space_Treaty http://en.wikipedia.org/wiki/Outer_Space_Treaty