LGM-35A Sentinel - Ground-Based Strategic Deterrent (GBSD) program

Desertfox said:
Its not like the Trident D5 is much newer, it would be 50yo tech by the time it got deployed, and the ground stuff would have to be replaced for D5 and then again for Sentinel... Going with D5 would be much more expensive for very limited benefit.
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D5LE is maybe 15 years old at this point.
 
Scott Kenny said:
D5LE is maybe 15 years old at this point.
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Never the less, no one is adopting it as a USAF system for reasons stated. And I’ll add one more: Trident uses solid thrusters because no on one wants hypergolic on a boat. This translates to less divert, which is more problematic with eight warheads rather than three.
 
Josh_TN said:
Never the less, no one is adopting it as a USAF system for reasons stated. And I’ll add one more: Trident uses solid thrusters because no on one wants hypergolic on a boat. This translates to less divert, which is more problematic with eight warheads rather than three.
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Wasn't considered an issue with 14 warheads as originally fielded.
 
Forest Green said:
Need at least 2,000 land-based ICBM warheads and another 2,000 SLBM warheads.
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Well the former is never going to happen, unless Sentinel has a significantly larger MIRV capacity than MM3. The later is probably doable but would require an expansion of the Columbia program, and a SLEP of Ohios (if that is even possible).
 
Josh_TN said:
Well the former is never going to happen, unless Sentinel has a significantly larger MIRV capacity than MM3. The later is probably doable but would require an expansion of the Columbia program, and a SLEP of Ohios (if that is even possible).
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SLEP of Ohios would require a refueling overhaul to get more than 2-3 more years out of them, and if you're not refueling them they're not going anywhere fast. They're going to be placed on some special care and feeding to squeeze those last couple of years out past the nominal core life.

Assuming that they're in good enough shape to continue going out to sea, and some of those hulls are 40 years old ALREADY so things are kinda questionable about that.
 
I think a refueling is out of the question but I could see a few more years out of some of them. I think the USN has already looked into which hulls might be the best candidates for extension as a fallback to Columbia delays. Even maintaining 1-2 extra boats year over year would add a lot of capacity. But long term there would just have to be more Columbias.
 
Josh_TN said:
Well the former is never going to happen, unless Sentinel has a significantly larger MIRV capacity than MM3. The later is probably doable but would require an expansion of the Columbia program, and a SLEP of Ohios (if that is even possible).
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400 x 5-6 warheads would work. Need at least 16 Columbias not 12.
 
Forest Green said:
400 x 5-6 warheads would work. Need at least 16 Columbias not 12.
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5-6 seems like a big ask in terms of volume, even if throw weight goes way up. I would expect the 50 "non deployed" MM3 silos would also be activated as part of the Sentinel program; post 2026 there's no restriction. In fact those silos would be perfect candidates for the initial infrastructure upgrades, since it would allow the other missile squadrons to remain active during construction.
 
Josh_TN said:
5-6 seems like a big ask in terms of volume, even if throw weight goes way up. I would expect the 50 "non deployed" MM3 silos would also be activated as part of the Sentinel program; post 2026 there's no restriction. In fact those silos would be perfect candidates for the initial infrastructure upgrades, since it would allow the other missile squadrons to remain active during construction.
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There are still 1,000 silos but only 450 hot ones at present. 5-6 warheads would be with a missile 2.11m wide necked to 1.7-1.8m wide at the upper stages.
 
Forest Green said:
There are still 1,000 silos but only 450 hot ones at present. 5-6 warheads would be with a missile 2.11m wide necked to 1.7-1.8m wide at the upper stages.
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For what’s it’s worth I asked about sentinel’s upload capacity on that NIDS call and was told it is classified.
 
Forest Green said:
There are still 1,000 silos but only 450 hot ones at present. 5-6 warheads would be with a missile 2.11m wide necked to 1.7-1.8m wide at the upper stages.
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Are the other 550 silos still owned/leased by the USAF? I had thought everything except the 450 were disposed of.
 
Forest Green said:
5-6 warheads would be with a missile 2.11m wide necked to 1.7-1.8m wide at the upper stages.
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Would be better to keep the diameter as wide as possible at the upper stages, otherwise you're really limiting your potential upload.

Besides, 2.11m is Trident diameter, so there are hot production lines for rockets that diameter.

If we are making a new missile, give it the maximum growth potential we can. Trident diameter, Minuteman length, 10 heavy warheads or HGVs to "in excess of 12,000km"
 
Scott Kenny said:
Would be better to keep the diameter as wide as possible at the upper stages, otherwise you're really limiting your potential upload.

Besides, 2.11m is Trident diameter, so there are hot production lines for rockets that diameter.

If we are making a new missile, give it the maximum growth potential we can. Trident diameter, Minuteman length, 10 heavy warheads or HGVs to "in excess of 12,000km"
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We want to keep a decent number of missiles, like 400. So we only need 5-6 per missile for 2,000 total. At 10 we'd end up with 4,000, which would be the most ICBM warheads ever deployed by the US by a considerable margin. There were only 2,310 even in 1988.

 
Forest Green said:
We want to keep a decent number of missiles, like 400. So we only need 5-6 per missile for 2,000 total. At 10 we'd end up with 4,000, which would be the most ICBM warheads ever deployed by the US by a considerable margin. There were only 2,310 even in 1988.

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The US also has Russia & an ever growing China to look forward to in the years ahead rather than just the Soviet Union. I can't even fathom what the future of space weaponry, tactical nukes, and SLBMs will look like.

If we return to the days of 24/7 Cold War patrols, LO unmanned aircraft with significantly longer loiter times, carrying nuclear-tipped hypersonic missiles will also add another dimension of complexity to the national security puzzle.
 
Forest Green said:
We want to keep a decent number of missiles, like 400. So we only need 5-6 per missile for 2,000 total. At 10 we'd end up with 4,000, which would be the most ICBM warheads ever deployed by the US by a considerable margin. There were only 2,310 even in 1988.

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Yes, I expect that the missiles would only get 5-6 warheads plus whatever penaids will fit.

I still want the potential to go a lot more warheads or a lot heavier warheads.
 
Defense Updates has put out this video about why the US STRATCOM commander wants the Sentinel to be MIRVed:


The head of the U.S. Strategic Command has called for "serious consideration" of a return to deploying intercontinental ballistic missiles, or ICBMs, with multiple nuclear warheads.
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The U.S. Air Force's LGM-30G Minuteman III ICBMs have this capability, but operational examples are presently only loaded with one warhead due to arms control agreements with Russia.
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But its successor, Sentinel ICBM could be deployed with more than one warhead.
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In this video, Defense Updates analyzes why the US STRATCOM boss wants Sentinel ICBM to be armed with multiple warheads?
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Given Putin and Xi's recent antics I'm not surprised at all.
 
NMaude said:
Defense Updates has put out this video about why the US STRATCOM commander wants the Sentinel to be MIRVed:







Given Putin and Xi's recent antics I'm not surprised at all.
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Exactly why I want Sentinel to be capable of throwing just as much as Trident at full load. And then we just load the birds to whatever the demands are, whether 1 warhead or 12.
 

The Sentinel ICBM remains affordable – because context matters - Breaking Defense

Adam Lowther and Curtis McGiffin argue in this op-ed that added context is needed before deciding that the Sentinel ICBM is too expensive.
breakingdefense-com.cdn.ampproject.org breakingdefense-com.cdn.ampproject.org
When the Cold War ended, the production of Peacekeeper was canceled. This left the nation with a force of only 50 Peacekeepers. This newest ICBM was retired in 2002, leaving the much older and less capable Minuteman III as the nation’s only ICBM.

In short, the United States kept its oldest intercontinental ballistic missiles in the field and took a three-decade-long holiday from building new ones. This robbed industry of a generation of engineers, scientists, and program managers with experience building ICBMs and their supporting infrastructure. It also ensured that no Air Force acquisition officer had any experience with ICBMs.
 
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NMaude said:
So assuming the ground test has been successful I wonder if we'll see a flight test before the end of the year? Will it be an all up test (All three stages live) or just a live first-stage with inert second and third stages?
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Unless they're doing some new SRM chemistry, I'd expect an all up test, all 3 stages live.
 

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