> Starlink would be the platform for the interceptor as discussed in Project 2025
This makes no sense—a plane change in LEO takes about as much energy as a launch to LEO. What you gain in proximity you lose in propellant. Interceptors on Starlink is nukes on the Moon.
LEO constellations make sense for sensing—it’s harder to plausibly deniably take out a ring of satellites than an early-warning radar. But not for interception.
> Castelion
SpaceX’s work on rapid turnaround and hypersonic reëntry absolutely has implications for missile intercept. But they’re contributors to the aim and not pursuing it themselves.
> point of hypersonic weapons (used for interceptor) is they start at orbital velocities
The point of hypersonic weapons is they can fly under the radar, literally, and manoeuvre. (I should say goal, because there is no stealthy hypersonic missile yet due to heat signatures.)
The hypersonic flight regime starts at Mach 5, or about 3,800 mph. LEO is at 17,000 mph. To leave LEO quickly, you need to cancel out a lot of that velocity, and that’s just to deörbit, I’m ignoring that you’ve gone from needing to pre-cool your engine to having to pre-cool your entire interceptor because you’re manoeuvring through the atmosphere with orbital energy.
Orbiting missile defence doesn’t make sense. It’s worse than launching from the ground for space intercept. It’s worse than launching from atmosphere for boost or terminal-phase intercept. If you look at what Griffin is doing versus saying, you’ll notice Castelion is building missiles designed to be launched from conventional platforms.
That’s Griffin talking again. Not the DoD. (I may have missed something. If you have an excerpt, I’m happy to respond to it.)
Even then, he doesn’t really make a case for space-based interception. He just says it isn’t as expensive as it was in the 80s, which is true. He also ends by talking about sensing from orbit which, as I said earlier, makes sense.
