Kinetic "Ortillary" Platform

[Graham Kennedy]

Designed to be a cheap and easily deployable form of "orbital artillery", a constellation of these satellites would be deployed into many different orbits around a planet - much like the GPS system only with many, many more satellites. They dont require any special launcher - each satellite is only 12.56 m long (41 feet 2.4 inches) and 3.1 m wide (10 feet 2 inches), so you can literally stack them by the hundreds on the boat deck of any Coalition warship (I did some quick calculations, and a single frigate that filled the boat deck three deep would stock 1,500 of them.) All you need to do is turn them on and shove them out the door and they'll deploy themselves.Each platform can sit in orbit for years on end waiting for the call.

When activated they shed their nose cover, revealing 54 kinetic rods. Each rod is a solid tungsten "dart" with a nose cover hiding a homing unit, and a set of fins at the back. The outer ring rods are 6.6 m long and 35.2 cm in diameter (21 feet 7.8 inches by 13.8 inches), massing 8,700 kg (19,175 lbs). There are two inner rings, one in front of the other, with each dart half the size (one eighth the volume and mass).

Impact velocity is approximately Mach 10. The larger darts hit with energy equivalent to roughly 11 metric tons of TNT, which is the equivalent from a hit by a MOAB bomb. See here for what that looks like. The smaller darts strike with the equivalent of 1,375 kg of TNT per hit.

In stowed configuration :


Orthographic view with person to scale :


Engines, power cell, and fuel tanks above and below. The satellites can change orbit to pretty much any inclination and altitude, many times over. Childs play for a civilisation that can push lightspeed in normal space :


Cooling fins open. I debated adding these, as they're really ancient tech by the Coalition era. Honestly, I jus tthought it looked kinda cool :


Nose cone jettisoned to show the teeth :


You do not want this pointing your way :

[Mikey]

Quite interesting. I like the idea; no use putting a lot of complex, expensive, and prone-to-fail mechanisms into a piece of materiel that's bound to just sit around for a while and then just drop bombs. Are the "darts" powered at all, or do they just depend on gravity and steer by adjusting the fins against atmosphere?

[Graham Kennedy]

No power other than a little battery to run the sensor and fins; the satellite givers them a boost to get clear and head down into the atmosphere, then they just fall on down under guidance from the fins.

Orbital KE weapons are actually a real thing that the US looked into back in the day under "Project Thor". Sci fi writer Jerry Pournelle originated the idea, and it features in one of his books, Footfall. The biggest problem with it today is that it takes a lot of energy/money to get the things into orbit in the first place, as compared to a bomb dropped from a plane. For a spacefaring civilisation that's not so much of a problem, of course, and if you're arriving at an alien planet with no infrastructure on the surface, these things would be just perfect. It doesn't even matter much if they get shot down, because they are so cheap and plentiful.

[Mikey]

So, nothing more than the dart itself, a receiver to take guidance instructions from the satellite, and a little battery to power the actuator for the fins? I like how simple it is.

[Graham Kennedy]

You could add a homing head, smart enough to recognise something like a tank or a ship from above and steer towards it. But for most uses you just feed it latitude and longditude coordinates and let it drop. The deorbit process only takes a few minutes, and with a few hundred satellites in orbit you never have to wait more than a few minutes for one to be in drop position. Simple, easy, cheap.