Orbital strikes would take upwards of half an hour to hit the ground. It wouldn't be useful for moving targets.

Also, not for a long time. Unless a new cold war starts, there wouldn't be much reason to do it when a fighter jet can carry anti-satellite missiles.

The costs are prohibitive and the platforms are not really necessary. I don't imagine we'll see it any time soon.

The Outer Space Treaty of '67 prohibits orbital weapons platforms.

So... never?

Quote from: MyNameIsCharlie on May 02, 2017, 03:04:22 PM

The Outer Space Treaty of '67 prohibits orbital weapons platforms.

So... never?

Only WMD platforms, actually.

No space nukes.

That's why Reagan's Star Wars bluff didn't get the US in trouble with the UN.

Many weapons platforms fall in a grey area. Kinetic bombardment is a good example of this.

Quote from: Ramona on May 02, 2017, 02:18:49 PM

Quote from: BaconShelf on May 02, 2017, 02:16:01 PM

Orbital strikes would take upwards of half an hour to hit the ground. It wouldn't be useful for moving targets.

Also, not for a long time. Unless a new cold war starts, there wouldn't be much reason to do it when a fighter jet can carry anti-satellite missiles.

not a payload dropped from space, more like a predator missile

There would be zero advantages to this system.

The ability to strike any target anywhere in the world within the hour with absolutely no preparatory measures?

Instead of sending our warships to NK and alerting them that we're reafy to take action, we instead just quietly slip a sattelite into geosync, which cuts the human cost of preparing an assault to nothing?

If we had anti naval weapons in space during the cuban missile crisis we could've made all the same threats to the USSR's fleet without ever endangering our own vessels or lives, though the possibilty of war would still be the largest concern, and not neutralized.

2047

Quote from: Ramona on May 02, 2017, 03:32:05 PM

Quote from: DAS B00T x2 on May 02, 2017, 03:19:52 PM

Quote from: Ramona on May 02, 2017, 02:18:49 PM

Quote from: BaconShelf on May 02, 2017, 02:16:01 PM

Orbital strikes would take upwards of half an hour to hit the ground. It wouldn't be useful for moving targets.

Also, not for a long time. Unless a new cold war starts, there wouldn't be much reason to do it when a fighter jet can carry anti-satellite missiles.

not a payload dropped from space, more like a predator missile

There would be zero advantages to this system.

The ability to strike any target anywhere in the world within the hour with absolutely no preparatory measures?

Instead of sending our warships to NK and alerting them that we're reafy to take action, we instead just quietly slip a sattelite into geosync, which cuts the human cost of preparing an assault to nothing?

If we had anti naval weapons in space during the cuban missile crisis we could've made all the same threats to the USSR's fleet without ever endangering our own vessels or lives, though the possibilty of war would still be the largest concern, and not neutralized.

and they couldn't detect and intercept the missile in the air like they can now why?

They totally can.

But that's equally true to missiles fired from the ground though, so all of my points still stand.

In practice, what would be the difference between a HE shell and a depleted uranium rod wrapped in tungsten? Chemical explosives? The delivery package would provide the energy. Not the warhead.

Quote from: MyNameIsCharlie on May 03, 2017, 01:25:10 AM

In practice, what would be the difference between a HE shell and a depleted uranium rod wrapped in tungsten? Chemical explosives? The delivery package would provide the energy. Not the warhead.

A warhead would be useless. These things would be Kinetic Kill.

Exactly. Space based platforms are neat. But banned until kenetic weapons are exempted

Hopefully never. I'd imagine a kinetic weapon that could pierce the earth's crust would do far more damage than any nuke could.

You'd also have to be accelerating it to relatavistic velocities to pierce hundreds of kilometres of solid rock.

OT. Here's some quotes that describe why Ortillery would be a waste of time (In the context of being a civilisation hanging around on only one planet. Obviously, if the Martian sandniggers want to try it they'd have to rely on Ortillery)

Or maybe it wasn't such a good idea in the first place. The blog Tales Of Future Past points out that neither the Moon nor Earth orbital bases turned out to offer any sort of advantage over surface-based missiles. Lunar bases are easy to target, require missiles with huge amounts of delta-V to deliver the nuclear weapon to the target on Earth, and will take days of transit time. Orbital bombs have utterly predictable orbits and can be seen by everybody (unlike ground based missiles), can only be sent to their target at infrequent intervals (unlike ground based missiles), and will require a deorbiting rocket with pretty much the same delta-V as a ground base missile. So what is the advantage? Please note that not all of these drawbacks apply to enemy spacecraft laying siege to Terra.

This one talks about why Rods from God aren't really all that advantageous to a non-spacefaring species.

A 2003 USAF report describes rods that are 6.1 m × 0.3 m tungsten cylinder The report says that while orbital velocity is 9 kilometers pre second, the design under consideration would have slowed down to about 3 kilometers per second by the time it hit the target. The report estimates that the rod will impact with a force of 11.5 tons of TNT. The back of my envelope says that a cylinder that size composed of pure tungsten will have a mass of 8.3 metric tons, but the figures in the USAF report imply that the rod has a mass of 8.9 metric tons. Which is close enough for government work.

11.5 tons of TNT per rod is pretty pathetic, you might as well use a conventional bomb. This is because 3 kilometers per second is 1 Rick, which means each kilogram of rod is equal to one kilogram of TNT, so why not just drop TNT from a conventional bomber?

An article in Popular Science breathlessly suggests that the rods will strike the target at 11 kilometers per second. This is 13.4 Ricks, which will give the rod an impact of 120 metric tons of TNT. That's more like it, now we are getting into tactical nuclear weapons levels of damage. But the article does not explain how the rod is suppose to start at 9 km/s and strike at 11 km/s after being slowed by atmospheric friction. Popular Science left that as an exercise for the reader.

The rod is admittedly quite difficult for the enemy to defend against. It is moving like a bat out of hell, er, ah, has a very high closing velocity, and it has a tiny radar cross section.

The trouble is, the "plasma sheath" created by atmospheric re-entry prevents remote control of the rod. Radio cannot pass through the plasma, so the bar has to be inertially guided. Or not. A Russian scientist thinks they have found the key to allowing radio signals to pass through the plasma sheath. A related problem is that anything on the rod that is not made of tungsten is going to want to burn up in re-entry. Things like the guidance computer, sensors, and hypothetical remote control radio.

The main drawback to Project Thor is the prohibitive cost of boosting the rods into their patrol orbits. Of course if you have a space-faring civilization, the rods can be manufactured already in orbit, thus eliminating the boost cost. Which means any planetary nation without a presence in space is going to be at a severe disadvantage, but that is always true.

Another problem is maintaining the rods in orbit. Things are going to break down, so you either have to have a budget to boost replacements or have assets in orbit that can do maintenance.

Finally, no, this is not the same as the Magnetic Accelerator Cannon from the Halo games. That is a coil gun, Project Thor is more like a weaponized version of dropping a penny from the top of the Empire State building.

sauce

Until we're building space stations and travelling to other worlds on a regular basis, conducting trade and industry in space, orbital strikes are as much of a meme as nuclear fusion. Once we're conducting campaigns to wipe out the Belter allahus and Europan iceslimes it's a different game but in the scope of the next few decades; pretty fucking unlikely.

You wouldn't want to send a projectile directly into the atmosphere. You'd want to enter at a shallow angle.

I will compute the orbital parameters later when I have a bit more time, but I will note that the situation you describe will not work on a world with a significant atmosphere. On Earth, for example, the projectile will slice through the exosphere and hit the mesosphere at a steep angle, rapidly getting to regions of air dense enough for the shock heating to incinerate the projectile while the ram pressure disintegrates it. Here, the atmosphere does not help. To get the atmosphere to help you need to enter at a shallow angle, where you can stay in the upper reaches of the mesosphere for long enough to let drag do its work without incinerating you. This would be something like the minimum energy solution I described earlier - or more likely an orbit with a periapsis at an altitude of 100 to 150 km or something similar.

Alternately, you can kill off much of your orbital velocity so the projectile enters the atmosphere at a much lower speed - similar to the method I described earlier, with the projectile dropping straight down.

For what it is worth, a projectile given 2 km/s delta-V straight down from a spacecraft in a circular 200 km altitude orbit above airless Earth will have a surface track distance of 781 km before impact, and will take 100.25 seconds for impact. It will hit with a speed of 8.275 km/s.

With an atmosphere, of course, it disintegrates long before reaching the ground.

It'll be a quite a bit easier to shoot down a satellite than you think. You can just force the satellite to fly into your pace junk.

The main point is that the orbiting invading spacecraft have nowhere to hide, while the defending ground units can hide in the underbrush.

Of course it is a bit easier to inflict damage on orbital person now that lasers have been invented. Keep in mind that if the planet in question has an atmosphere similar to Terra, laser beams with wavelengths shorter than 200 nanometers are worthless for either bombarding spacecraft or planetary defenders. Such frequencies are totally absorbed by the atmosphere, this is why they are nick-named "Vacuum frequencies". The frequencies include Ultraviolet C, Extreme Ultraviolet, X-rays, and Gamma-rays.

And keep in mind that the defender's anti-orbit rocket also does not need a warhead, a bursting charge surrounded by nails and other shrapnel will do. The relative velocity between the more or less stationary cloud of shrapnel and the orbital speed of orbital person will do the rest. Orbit person will be riddled by shrapnel traveling at about 27,500 kilometers per hour relative.

From the first page I linked

Good job BaconShelf you made Sol commit suicide

I crashed his orbital kill satellite with no survivors