U.S. Space Force Discussion Thread

[DDE]

7 hours ago, insert_name said:

Yes, the two types of spacecraft, radar observation and space based weapons.

I do find the focus on radar fascinating, although I suspect it's a product of sensor limitations. Telling that the object isn't tumbling (is stabilized) and doesn't have major antennae sounds like the totality of what radar observations would yield.

[DDE]

Having taken a better look at the study, it's more of a fetish on "maneuver".

[DDE]

An interesting, if hawkish article. Belongs in this thread due to a pronounced viewpoint.

https://thespacereview.com/article/4336/1

[SunlitZelkova]

14 hours ago, DDE said:

An interesting, if hawkish article. Belongs in this thread due to a pronounced viewpoint.

https://thespacereview.com/article/4336/1

Regardless of its points on ASAT arms control as a whole, something like a Partial Anti-Satellite Test Ban Treaty (along the lines of nuclear test ban treaties), banning kinetic ASAT tests, would be in everyone's interest and be helpful.

On the other hand, the proposal for "norms" is pretty silly. Unless you announce in your Nuclear Posture Review you are going to respond to ASAT attacks with the use of low yield nuclear weapons (glances at Trident II with W76-2s), I can't see anyone agreeing to "norms" or taking them seriously.

I say this because unlike "smaller" conflicts, which international rules have supposedly been good at regulating conduct on, the only instance in which ASAT weapons will be used in anger is in a "great power conflict", and if the situation has deteriorated to a great power conflict, there will likely be no holds barred by one side or the other sooner or later.

In any case though, I wonder what these norms are intended to prevent outside of kinetic ASAT tests. Loitering? Close passes? These already happen on Earth completely unregulated when aircraft and/or ships intercept each other, so I fail to see how such things happening in space are so egregious. If anything, it should be even more acceptable in space, because unlike an aircraft breaching the restricted airspace around a carrier battle group, apart from the objects themselves, orbit belongs to "everyone", and thus can't be violated in any manner apart from an actual collision.

[SunlitZelkova]

In Space Force with Steve Carrell, there is a mural at the Space Force base in Colorado featuring astronauts raising the American flag on the Moon in a manner basically identical to that of the flag raising on Iwo Jima. This was likely meant as a comedic take on the militarization of space- humanity’s bloody battles but in (what was) an ostensibly peaceful locale. Astronauts with guns still feels very meme-like. The Space Force itself does have many meme-worthy elements.

Thus this was rather surprising to see-

I can’t help but see this with the same meaning the original has- one group triumphing over another. Hardly a good image of “cooperation”.

Now I want to see a cosmonaut raising the Roscosmos flag over Shackleton Crater in a manner similar to the famous Reichstag photo.

[DDE]

4 hours ago, SunlitZelkova said:

I can’t help but see this with the same meaning the original has- one group triumphing over another. Hardly a good image of “cooperation”.

Posted on April 12, no less.

[kerbiloid]

https://spacenews.com/space-force-briefing-on-military-space-race-catches-jeff-bezos-attention/

[SunlitZelkova]

https://x.com/planet4589/status/1734272637226856878?s=46&t=Jd73T2beq0JLNtwTy1uR5A
 

A little interesting tidbit- a GBI interceptor test conducted two days ago was against an IRBM class target dropped from a C-17. This was probably intended to test the ability to detect and intercept air launched ballistic missiles, given China has now put them into limited service.

[kerbiloid]

They should test the airship missile launch first.

[DDE]

On 4/13/2022 at 6:15 AM, SunlitZelkova said:

The Space Force itself does have many meme-worthy elements.

https://spacenews.com/space-force-inks-deal-with-microsoft-for-mixed-reality-training/

AFAIK Microsoft was divesting from AR...

[StrandedonEarth]

Galactic Defender in the background, lol

[JoeSchmuckatelli]

On 1/14/2024 at 10:15 AM, StrandedonEarth said:

Galactic Defender in the background, lol

They gotta have somewhere to train.

[SunlitZelkova]

I saw an interesting article about space-based missile defense. Because it includes some political stuff, I'm just copying over the engineering parts.

Quote

But previous efforts to field a space-based missile interceptor system did not move forward in large part because the technology was immature, and the costs were prohibitive. But times have changed. This article provides an updated rough order of magnitude estimate for what such a system might cost. The analysis is based on the methodology outlined in a 2004 report by the American Physical Society (APS) and is updated with current assumptions.

Intercepting a missile during the boost phase is ideal because the missile cannot deploy decoy warheads and is much easier to track. It is challenging, however, because of the tight timeline involved. An intercontinental ballistic missile (ICBM) typically has a boost phase that lasts three to four minutes, and it may take 30 seconds or more before a launch is detected and a track is established. Even with the improved coverage of the new missile tracking layer being deployed by the Space Force in the coming years, it is reasonable to assume that a space-based interceptor would have roughly 150 seconds to strike its target during the boost phase.

To be effective, interceptors would need to be based in low Earth orbit (LEO) to intercept the missile inflight. Using the aforementioned APS model, if the interceptors are kept in orbit at an altitude of 500 km, approximately 1,900 interceptors would be needed to provide continuous coverage of all points on Earth with an average of two interceptors. Each interceptor, including propellant, kill vehicle, and support systems, would weigh around 900 kg. Using an 85 percent learning curve, the average procurement unit cost (APUC) of each interceptor in a constellation like this is estimated to be between $4.4 and $8.9 million, for a total procurement cost of $8.6 to $17.2 billion (all costs are in 2025 dollars). An additional $2 to $4 billion would likely be needed for non-recurring development costs, and the constellation would need to be replenished about every 5 years as satellites age and their orbits decay.

Launch costs are perhaps the area where updated assumptions matter the most because launch costs have fallen significantly in the past decade and are expected to fall by another factor of ten in the coming years. At the low end (using the most generous assumptions) launching a constellation of 1,900 interceptors with a mass of 900 kg each would require at least 12 of SpaceX’s Starship launch vehicle with a payload capacity of 150,000 kg each and an estimated cost of $70 million per launch (an aggressive assumption). At the high end, it would require 39 of Blue Origin’s New Glenn rocket with a payload capacity of 45,000 kg and a cost of up to $150 million per launch. Given these assumptions, the overall launch cost would be somewhere between $0.8 to $5.9 billion for the constellation. As in the case of the interceptors, launch costs would be incurred each time the constellation needs to be replenished every five years or so.

The total cost to develop, build, and launch an initial constellation of 1,900 space-based interceptors would likely be on the order of $11 to $27 billion. If this seems like a no-brainer to [snip], there’s a catch. The system described above is only sized to intercept a maximum of two missiles launched in a salvo. That means that if an adversary launches a salvo of three missiles, only two could be intercepted and at least one would get through because all of the other interceptors in the constellation would be out of range—what is known as the absenteeism problem.

The grim reality is that the cost of a space-based interceptor system scales linearly with the number of missiles it can intercept in a salvo, excluding development costs. Designing the system to have an average of four interceptors in range (and thus able to intercept a salvo of four missiles at once) requires twice as many interceptors (some 3,800 in total) and twice as many launches. This is true even if multiple interceptors are housed together. A space-based interceptor system for missile defense does not scale well when compared to adversary missile forces. While the costs have come down and the technology has matured, the physics of space-based interceptors has not changed.

That 2004 report also has some content that kinda pushes the boundaries of the forum rules, but if you're interested, just Google "Report of the American Physical Society Study Group on Boost-Phase Intercept Systems for National Missile Defense: Scientific and Technical Issues," and it pops up.

So looking at the numbers here, USSF would have 780 ICBMs to intercept from... the other two big guys (326 + 454)... by roughly 2035 or so. That would require 741,000 satellites, and it requires the assumption that every single interceptor will work perfectly, because there are no backups.

Curiously, that five-year lifespan is the same as a Starlink sat. But Starlink is planned to have 42,000 satellites at most.

With... let's just say, the smaller guy... some estimates put the number of ICBMs he might build at maximum at roughly 60 or 100. Of course, who knows, he might build more. But if that is the maximum capacity he has, 95,000 satellites would be required at maximum, and 57,000 at minimum. That's actually not that bad at all, and might be doable. Still, it requires every satellite working perfectly. No "volleys" or "salvos."

Ignoring the political aspects of the system, I'm very interested to see how advocates for this are going to approach the engineering and economical challenges.

If it doesn't work out I'm hoping that "Iron Colander" catches on as a nickname for the system like "Star Wars" did for SDI