v0.9: 227 kg (500 lb)
v1: 260 kg (570 lb)
v1.5: ~306 kg (675 lb)
v2 mini: ~740 kg (1,630 lb)
v2: ~1,250 kg (2,760 lb)
It’s definitely nonsense. As in if they are attempting it it’s virtually fraud on the American taxpayer.
Barring a sci-fi breakthrough in propulsion technology (or vacuum directed energy weapons), it cannot work. (And even if you have that propulsion technology, its existence obsoletes the concept again. You’d need to rewrite orbital physics to make plane changes a better idea than new launch from the ground. It’s just a phenomenally fucked idea.)
> the latest versions of the starlink satellite are significantly heavier than prior generations
This is in the same calibre of evidence as that for more planes meaning chemtrails are real.
So, any secret military project is effectively fraud?
No. A project based on bunk science is a fraud.
To be clear, space-based boost interception isn't impossible. You can do it. But in practically every case it's inferior to ground-based systems (with space-based early detection). The only case where it has merit is in containing a specific, small adversary with very few missiles, e.g. North Korea or Iran. But even there, a ground-based solution is superior in stealth, numbers and cost.
Space-based missile intercept is a political project. That doesn't mean it won't be done. But it's not something SpaceX is working on, or would work on without first cashing a substantial cheque.
Namely, the plane change from the pre-positioned orbit to one that intersects with the target? Sorry if this is a dumb question, but is it really that bad? No way to get the loitering orbits closer to an interception than launching from the ground? (Ed: well, those definitely wouldn't be the orbits starlink is on, I think I can see that at least)
(The guy you're responding to has mostly deleted their posts, so I'm missing context, but I did get as far as the wiki page for brilliant pebbles.)
Yes. The closer you get to the surface the faster the orbit which means while you have less orbital energy to kill on approach you need more birds to cover a given area. (To communicate how unintuitive orbital mechanics can be, consider that thrusing "up" or "down" (radial in or out) doesn't actual increase or decrease your mean altitude [1]. You have to fire retrograde, which means a long, swooping, predictable, observable (and thus avoidable) approach to intercept unless you're Project Orioning it [2].)
> guy your responding to has mostly deleted their posts
They were repeating a conspiracy theory around SpaceX's actual purpose being to create a space-based missile defence system. The proof being there are senior people who were involved with the latter who have been around SpaceX. It's total nonsense somewhat orthogonal to why space-based missile defence is between difficult and stupid.
The core concept of boost-stage (i.e. in the atmosphere) space-based intercept isn't physically fucked. It's just that every case where one presents it, ground-based interception--including at the boost phase--does better. You can hide your interceptors better. For any given cost, you can deploy more of them (and more early-warning/targeting satellites). And even primitive ASAT can reliably punch a hole in it.
The only benefit is political/PR, because it sounds cool--that doesn't rule it out. But it isn't something SpaceX is working on much less was founded for.
(Space-based midcourse (i.e. in vacuum, while the warhead coasts) interception is stupid on all levels. It's a slightly more difficult version of blanketing the skies in drones for intercept--except you have more volume to cover and have planes which send off a screaming signal every time they change course.)
[1] https://space.stackexchange.com/questions/44608/what-happens...
[2] https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
Nope. And I can say this with more authority than almost anything on HN.
> Trump & Elon literally discussed it on X a few weeks ago
One, they discussed a lot of things. Two, they discussed capability. As I said, any launch system provides this capability theoretically. But (a) the capability is based on the faulty premise that pre-positioned orbital interceptors are superior to stealthy ground-based ones. And (b) it’s going to be true for any cheap space-launch system. (I say cheap because economies of scale mean cheap and frequent are virtually redundant.)
This entire theory comes out of people with no military background, no political experience and no aerospace engineering training wanting to feel special about being “in the know.”
You're presuming a lot there.
If you can do orbital math, you can verify the plane-change economics. If you’ve even talked to anyone in ABM, which granted requires clearance, you understand why the actual spending in ABM—globally—goes into ground-based interceptors.
This is a tailor-made conspiracy theory for someone who substitutes doing the damning math for connecting bits of string between people and tweets. If you have any domain experience or connections, it’s trivially excludable. That’s why I can shoot it down (hehe) with unique confidence.
https://nap.nationalacademies.org/read/13189/chapter/4?term=...
Your question about delta-V is answered in that same report a few pages above.
That’s how you read “in principle” and “in theory”? The cost of launch is used, in the third bullet, to justify not analysing the idea further. Not as the “only…limitation.”
As your source says, even a working space-based boost-phase interceptor is trivially defeat-able with “primitive” ASAT capabilities.
Brilliant pebbles are a fucked concept. You’re citing a no-math NAS paper for good reason—it’s good to speculate about it in case we learn something new about how gravity works. Barring that, it’s well-recognised nonsense.
Boost phase interception using a constellation of several thousand hypersonic glide vehicles circumvents the plane-change problem; I'm sure you know that. I'm sure you also know that the reason nobody has seriously pursued such a solution before is because putting tens of thousands of interceptors into orbit is absurd.
Was absurd.
Does Starship enable brilliant pebbles? Sure. But that’s because it provides easy access to space. Starlink could be described as a network of communication ‘pebbles’, as could Starshield, SpaceX’s actual military contract [1].
(Starship provides a technology platform for rapid launch. That’s more valuable for missile defence than orbital nonsense for intercepting warheads by way of predictable and observable plane-change manoeuvres.)
[1] https://en.m.wikipedia.org/wiki/SpaceX_Starshield