US Airpower in this Global Thermonuclear War scenario

[arian]

[SM-3 BlkIIB ie. NGAM would be true ICBM counter if they ever build it.

SM-3IIA will get there too. More importantly, it would really ruin the plans of anyone planning "boost-glide" weapons.

A "boost-glide" similar to the US system would be mostly invulnerable from such exo-atmospheric intercepts because it spends most of its flight in glide phase. But the Chinese systems are more or less similar to Pershing...they are only capable of preventing fixed defensive interceptors by re-entering the atmosphere too early for them to engage, but don't really have the glide ability for long-ranges. This is fine against a fixed defense, but against mobile interceptors which can engage you in the much longer ascend and exo-atmospheric flight, it is no defense.

[popcorn]

[SM-3 BlkIIB ie. NGAM would be true ICBM counter if they ever build it.

SM-3IIA will get there too. More importantly, it would really ruin the plans of anyone planning "boost-glide" weapons.

A "boost-glide" similar to the US system would be mostly invulnerable from such exo-atmospheric intercepts because it spends most of its flight in glide phase. But the Chinese systems are more or less similar to Pershing...they are only capable of preventing fixed defensive interceptors by re-entering the atmosphere too early for them to engage, but don't really have the glide ability for long-ranges. This is fine against a fixed defense, but against mobile interceptors which can engage you in the much longer ascend and exo-atmospheric flight, it is no defense.

Yeah.. I was thinking more of a mid-course intercept where NGAM could complement GBI.

[armedupdate]

It just doesn't. In any case there's no reason to cite Atlas performance for anything today.

This was the Atlas warhead design:
.

Judging by this video the end of the warhead, the reentry vehicle is pretty aerodynamic.
https://www.youtube.com/watch?v=LTLA1dPby-g

SM-3IIA will get there too. More importantly, it would really ruin the plans of anyone planning "boost-glide" weapons.
A "boost-glide" similar to the US system would be mostly invulnerable from such exo-atmospheric intercepts because it spends most of its flight in glide phase. But the Chinese systems are more or less similar to Pershing...they are only capable of preventing fixed defensive interceptors by re-entering the atmosphere too early for them to engage, but don't really have the glide ability for long-ranges. This is fine against a fixed defense, but against mobile interceptors which can engage you in the much longer ascend and exo-atmospheric flight, it is no defense.

I think gliders are pretty overrated. It spends a lot of time inside atmosphere making it easier to kill by a normal SAM.

[arian]

Judging by this video the end of the warhead, the reentry vehicle is pretty aerodynamic.
https://www.youtube.com/watch?v=LTLA1dPby-g

The pointy red thing in the video isn't the warhead but contains the guidance section of the warhead. The actual warhead is the gray thing in the back. The red bits burn up on re-entry so they provide no aerodynamic benefits. The actual operational Atlas missiles didn't even have the same pointy bit at the end. The part that actually re-enters the atmosphere is the one in the picture above I posted. As you can see, it has a broad heat shield to protect the warhead from re-entry, which means by design it is slowing down quite a lot more and faster than modern RVs. It can't be comparable at all.

I think gliders are pretty overrated. It spends a lot of time inside atmosphere making it easier to kill by a normal SAM.

I think most people think anything that has some aerodynamic capability is a "boost-glide" weapon, when in reality it is just a maneuverable RV. Not everything that can have some "glide" to it is a boost glide weapon. The Chinese thing looks to be very similar in design to a Pershing RV which was technically a "boost-glide" in the sense that it had some short glide capability. But it is nowhere the same or comparable to what the US tested, which is a real "glide" weapon for most of its flight.

The Chinese system could be useful for two scenarios:

1) Maneuverable RV which requires a steep reduction in speed to allow for maneuvering and aerodynamic effect (or if they are terminally guided they also need to slow down)

2) Make the job of fixed exo-atmospheric defenses harder. The warhead re-enters the atmosphere earlier than the range at which an exo-atmospheric interceptor can engage it, and then glides the rest of the way, outside (beneath) its reach. This depends of course on the range at which an interceptor can engage it, and detect it (it may not work for GMD for example), and on how long the warhead can glide (judging by what the Chinese vehicle looks like, probably not a lot. It would have to be several thousand miles of glide to actually make a difference against GMD)

SM-3 can screw with this because you can have SM-3IIA armed ships anywhere, a few thousands miles into the pacific, and now your ICBM can still be vulnerable to them exo-atmospherically since that's where it's spending a lot of its flight anyway.

As for conventional SAMs engaging boost-glide warheads, that depends on the speed and altitude (and probably 100 other things) at which it is gliding. But something like SM-6 would have an incredibly small window of opportunity against it, so I don't think that's realistic.

[sferrin]

May be wishful thinking. Or, just the only option available. Or maybe its ok against a Nork ICBM given the distances and trajectory involved. We don't know enough about all the variables involved to know.

Or maybe it's got ICBM capability. Occam's razor and all that. Granted, going to Hawaii from North Korea is only going about 5000 miles vs say 7k or 8k for a long range ICBM shot but 5000 miles is still WELL into ICBM ranges. There's a very interesting document I'll hunt up later today about THAAD. In it it suggests that THAAD might have ICBM capability, and describes the how of it. That the US Army has them in Hawaii to deal specifically with ICBM shots, and that THAAD was considered for the ASAT shot lends weight to this. The real world limitation would be getting enough advance notice to be able to get a THAAD KKV in position when the RV arrives. For the ASAT shot they had assets in addition to the Aegis radar in order to make it. It took about 3 minutes for the SM-3 to get to the satellites altitude. Given the satellites speed, had they been limited to only the ships radar they likely wouldn't have had enough time to get the KKV into a favorable position, and likely been trying to hit the thing broadside. However, an RV would be traveling toward THAAD generally and THAADs radar has significantly more range than Aegis.

[sferrin]

[SM-3 BlkIIB ie. NGAM would be true ICBM counter if they ever build it.

SM-3IIA will get there too. More importantly, it would really ruin the plans of anyone planning "boost-glide" weapons.

A "boost-glide" similar to the US system would be mostly invulnerable from such exo-atmospheric intercepts because it spends most of its flight in glide phase. But the Chinese systems are more or less similar to Pershing...they are only capable of preventing fixed defensive interceptors by re-entering the atmosphere too early for them to engage, but don't really have the glide ability for long-ranges. This is fine against a fixed defense, but against mobile interceptors which can engage you in the much longer ascend and exo-atmospheric flight, it is no defense.

THAAD ER would be a nice gift for actual boost glide weapons as well.

[sferrin]

I think most people think anything that has some aerodynamic capability is a "boost-glide" weapon, when in reality it is just a maneuverable RV.

Boost gliders are things like the BGRV, HTV-2, and the Indian Shaurya, and spend the majority of their flight gliding.

[armedupdate]

My point is ICBM reenters at around 30 seconds before it hits its targets. That is 4.6 km/s spend in the atmsophere if it was a 45 degree shot. So Mach Mach 13 on average. If it began Mach 20, the final phase should be in THAAD's envelope.

Don't gliders dive to the a target much slower? If it began it's glider at Mach 10, what are expected speeds of when it drops?

[arian]

I think most people think anything that has some aerodynamic capability is a "boost-glide" weapon, when in reality it is just a maneuverable RV.

Boost gliders are things like the BGRV, HTV-2, and the Indian Shaurya, and spend the majority of their flight gliding.

HTV-2 did. These other Indian things absolutely do not. They "glide", or rather fall in a flatter trajectory while maintaining maneuvering capability, for a couple of hundred miles. That is only a substantial portion of the flight in that they are short-range missiles to begin with. But they most certainly do not spend the majority of their time gliding. Very far from it.

The Indian systems are similar in concept and execution to Pershing. The only difference is that Pershing did its aerodynamic slowing and "gliding" to be able to guide itself onto a target, while the Indian system does the same for the purposes of achieving manuvrability.

But these are different from HTV-2 which had several thousands of miles of glide for the purposes of re-entering the atmosphere long before an exo-atmospheric interceptor could engage it.

Not to mention the speeds involved, with HTV-2 being a Mach 20 glide weapon, while these Indian/Chinese/Pershing type aerodynamic maneuvering "glide" weapons being much slower.

[arian]

My point is ICBM reenters at around 30 seconds before it hits its targets. That is 4.6 km/s spend in the atmsophere if it was a 45 degree shot. So Mach Mach 13 on average. If it began Mach 20, the final phase should be in THAAD's envelope.

That would depend on where THAAD needs to engage the target. It has a minimum range since it needs time to correct for point of intercept and maneuver, which means its minimum range may be 100-120km to begin with. Now that's not altitude, that's range, but its probably at a very high altitude as well.

[sferrin]

HTV-2 did. These other Indian things absolutely do not. They "glide", or rather fall in a flatter trajectory while maintaining maneuvering capability, for a couple of hundred miles. That is only a substantial portion of the flight in that they are short-range missiles to begin with. But they most certainly do not spend the majority of their time gliding. Very far from it.

I'm not talking about Indian guided RVs in general. Yes, those are more Pershing II like. I'm speaking of Shaurya specifically. It is a boost glider. (At high speed one doesn't need wings to glide as body lift alone is sufficient.)

But these are different from HTV-2 which had several thousands of miles of glide for the purposes of re-entering the atmosphere long before an exo-atmospheric interceptor could engage it.

As did BGRV. BGRV was arguably more impressive than HTV-2.

Not to mention the speeds involved, with HTV-2 being a Mach 20 glide weapon, while these Indian/Chinese/Pershing type aerodynamic maneuvering "glide" weapons being much slower.

Irrelevant.

[arian]

I'm not talking about Indian guided RVs in general. Yes, those are more Pershing II like. I'm speaking of Shaurya specifically. It is a boost glider. (At high speed one doesn't need wings to glide as body lift alone is sufficient.)

Shauraya is the one that has about 200 miles of "glide", in its maximum range configuration (1,900km with a small warhead). In short range profile (its 700km max range) it spends all of its time inside the atmosphere, but that is irrelevant to this discussion. No way is it the same "boost-glide" as what we're talking about. It is still little different than Pershing type profile, in its long-range configuration, and a longer-ranged SRBM in its short-range configuration.

I'm not saying it needs wings, but it just doesn't glide very far and spends most of its time in a traditional ballistic missile profile.

Irrelevant.

Its relevant in the trade-off made between avoiding exo-atmospheric and endo-atmospheric interceptors. If you try to avoid exo-atmospheric interceptors (which something like that Indian missile really can't do with only a 200 mile glide, since it will still be within reach for majority of its flight profile), but end up slowing down to Mach 5 or some other similar figure, then you're now potentially well within the engagement envelope of something like SM-6 and THAAD and PAC-3 (and even SM-3 at high enough altitudes). So have you really made the right trade-off? This Indian missile is nothing new in its capabilities that our targets don't already mimic.

On the other hand, if you can do that, and maintain Mach 20 (for thousands of miles), then you're outside of both exo and endo interceptors. That's relevant.

[arian]

Here's what the Indians claim of their missile:


So they claim that in its long-range version (with a small 140kg warhead), it can "glide" between about 1,300 and 1,800km (so 300 miles). While this is good, it isn't in the same class as what is needed to counter interceptors involved here: SM-3 would still be able to intercept it in the long ballistic flight, and terminal defenses would still be able to intercept it because it has to slow down considerably.

To achieve HTV-2 type of "boost-glide", you need either much better aerodynamic lift or multiple boost phases.

In the short-range profile, it is little different from all the other contemporary theater ballistic missiles. Theoretically, they are all "hypersonic glide" weapons since they all use some aerodynamic lift and don't follow a ballistic trajectory and are inside the atmosphere and are hypersonic. So that's just BS word games from the Indians.

Speed, range, time to endo-flight etc are all the really important parameters to consider here. Not whether something can "glide". Theoretically, most contemporary theater ballistic missiles can and do.

PS: And as far as I know, they've never actually tested it in its long-range configuration either. Seems to be all conjecture, if they haven't done so.

[jetblast16]

[jetblast16]

armedupdate - great thread

I suppose it's a matter of viewpoint, but in the event of a shooting war with nukes, all sides lose. The only thing left would be bragging rights on who "lost" the least. Depending upon the amount of tonnage detonated, the entire Earth could be affected, due to a global increase in background radiation, from the effects of nuclear fallout. There would be no clear winners.