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

Josh_TN said:
Security would still be an issue, and kinda hard to camouflage.
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Works for Pantex though. NNSA transport trucks have SMGs in the doors and you just shoot anyone who tries to steal the truck. Otherwise they use normal freight traffic and LEOs are simply notified of a special cargo coming through, but not necessarily when or where. This mission could be adapted easily to nuclear missile launch vehicles.

The real counterargument is that it would make every truck stop into a DGZ, I guess.
 
uk 75 said:
Can I ask a stupid question?
If Trident missiles are accurate enough is the only reason for a land based missile to have a heavier payload?
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Ironically, the Minuteman and Sentinel have a much lower payload than Tridents, only carrying 1-3 warheads.

Originally, only land-based ICBMs had the accuracy to hit hardened targets like HQ buildings or silos.
SLBMs were short ranged due to small size, but their range and accuracy got better every generation (basically doubling range every generation).

Picture your local sportsball field, the one with a huge parking lot. First generation SLBMs (Polaris) would land somewhere inside the parking lot. Second generation SLBMs (Poseidon) would land inside the stadium. Third generation SLBMs (Trident 1) would land in the infield of a baseball diamond. Fourth generation SLBMs (Trident 2) would land on the pitcher's mound.

So, Polaris and Poseidon were for destroying cities or maybe airfields. "If you launch, you won't have any cities left." In practice, not usable for a first strike because they couldn't hit missile silos reliably.

Trident 1 is getting accurate enough for weaker-construction silos.

Trident 2 is accurate enough for hardened silos.


Flyaway said:
Stop work order for Command & Launch Segment as the entire programme is undergoing restructure due to triggering the Nunn-McCurdy Act:
www.airandspaceforces.com

Air Force Orders Halt to Some Work on Sentinel ICBM

The Air Force is pausing work on launch facilities for its new Sentinel intercontinental ballistic missile program (ICBM).
www.airandspaceforces.com www.airandspaceforces.com
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Considering that the silos and wiring weren't even in the original RFP for the bids, I'm surprised that the bidders didn't file a complaint first!

The whole reason for Nunn-McCurdy breach is the silos and wiring, that the USAF thought was in good enough shape to reuse but detailed inspections said "that is a lie".
 
I see some parallels with the evolution of the UK nuclear deterrent.
I can see no value in fixed missile silos and mobile ICBMs do not seem to solve the problem.
Bomber launched weapons offer some ability to threaten an opponent visibly
 
That is certainly true in China and Russia but as in the UK any infrastructure built by the government faces public opposition, delays, poor management and massive cost overruns
 
uk 75 said:
That is certainly true in China and Russia but as in the UK any infrastructure built by the government faces public opposition, delays, poor management and massive cost overruns
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That's a constant question of proper balance between personal liberty and government control that made a state efficient. As everyrhing else, it changes with technology development. At some point its more efficient to have more liberty and less control; at some point the opposite is true. The balance is dynamic; there is no "forever solution"
 
uk 75 said:
That is certainly true in China and Russia but as in the UK any infrastructure built by the government faces public opposition, delays, poor management and massive cost overruns
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Still, there are wast areas of unused land even in USA; Nevada deserts, for example. And the matter of infrastructure cost could be lessned by switching toward the Soviet concept of storing missile in sealed container, reducing the silo to just a hardened storage container. You could hire private companies to construct thousands of silos, and then just move a limited number of missile containers & decoys between them. No extrenal observation could be sure, what exactly is in container, loaded in silo number 5433; a missile, or a dummy weight?
 
uk 75 said:
I see some parallels with the evolution of the UK nuclear deterrent.
I can see no value in fixed missile silos and mobile ICBMs do not seem to solve the problem.
Bomber launched weapons offer some ability to threaten an opponent visibly
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The Brits base their deterrence more on budgets and less on actual capabilities. Evident by the fact that they lacks a proper triad, something even the struggling US of A is still upholding. I cant blame them, with a devil like the Treasury holding their throat like that.

Subs sailing in international water can be drowned at a moment's notice with nothing more ambiguous than a "mis-directed" UUV. It is a hypothetical, borderline baseless hypothetical of course given the history of SSBN-related incidents versus silos and thelike but sub-based deterrence base its validity wholely on stealth. And a tiny bit on trajectory shaping, but you get the idea. The more sensors improve the less survivable SSBNs become.
ICBMs though, they are obviously there. Silos can be made as durable as possible. And then there are exotic solutions like tunnel networks that Iran and the PRC already have extensive experience on. The efforts required to actually threaten these installations would be so colossal and obvious and for the entire Cold War could only be done by full scale nuclear attack, and probably still now.

So in the end, all three arms of the triad complement each other. Sure it will cost you an arm and a leg but you can probably afford decent insurance with that money. Unless STRATCOM and Congress is willing to move to more out-of-the-box thinking like orbital basing and violate every treaties on space warfare in the meantime.
 
uk 75 said:
That is certainly true in China and Russia but as in the UK any infrastructure built by the government faces public opposition, delays, poor management and massive cost overruns
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There's lots of government land that already has missile silos in it in the US. Putting a new silo in that land is not going to attract much protest beyond the usual "Hey, you need to do the Environmental Impact Statement for this" legally-required delays.



yeetmahboi said:
Subs sailing in international water can be drowned at a moment's notice with nothing more ambiguous than a "mis-directed" UUV. It is a hypothetical, borderline baseless hypothetical of course given the history of SSBN-related incidents versus silos and thelike but sub-based deterrence base its validity wholely on stealth. And a tiny bit on trajectory shaping, but you get the idea. The more sensors improve the less survivable SSBNs become.
ICBMs though, they are obviously there. Silos can be made as durable as possible. And then there are exotic solutions like tunnel networks that Iran and the PRC already have extensive experience on. The efforts required to actually threaten these installations would be so colossal and obvious and for the entire Cold War could only be done by full scale nuclear attack, and probably still now.
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SSBNs have a rescue buoy. Or rather, a "reason we're sunk" buoy. It can be set to send one of two messages: "Sunk-accident" and "Sunk-enemy action". The buoy signal can be changed in seconds, it's a simple lever switch that normally sits set on "accident".



yeetmahboi said:
So in the end, all three arms of the triad complement each other. Sure it will cost you an arm and a leg but you can probably afford decent insurance with that money. Unless STRATCOM and Congress is willing to move to more out-of-the-box thinking like orbital basing and violate every treaties on space warfare in the meantime.
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It's arguable that the Outer Space Treaty has already been violated by Russia and possible China.
 
Scott Kenny said:
There's lots of government land that already has missile silos in it in the US. Putting a new silo in that land is not going to attract much protest beyond the usual "Hey, you need to do the Environmental Impact Statement for this" legally-required delays.




SSBNs have a rescue buoy. Or rather, a "reason we're sunk" buoy. It can be set to send one of two messages: "Sunk-accident" and "Sunk-enemy action". The buoy signal can be changed in seconds, it's a simple lever switch that normally sits set on "accident".




It's arguable that the Outer Space Treaty has already been violated by Russia and possible China.
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You still face the fact the subs have been sunk by conventional means so the question of “do you go nuclear” is not easy.

ICBMS, not withstanding some fantasy of drone or SpecOps attack you must attack the homeland with more than likely 2 warheads “per aim point” using up a large percentage of your deployed arsenal and still, even 100% Pk, have to face the SSBNS and bombers.
 
Scott Kenny said:
If an SSBN has been sunk by enemy action, I greatly suspect that the response will be nuclear.
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What is the point of deterrence if the enemy moves audaciously and there is no retaliation? To your point, I think the response would have to be nuclear on principle. On this line of thinking, I can foresee an attack on a CSG provoking a nuclear response. Perhaps not instantly, but I think the train has already left the station in this scenario. Call me dramatic, but I believe escalation dominance is key.
 
Scott Kenny said:
SSBNs have a rescue buoy. Or rather, a "reason we're sunk" buoy. It can be set to send one of two messages: "Sunk-accident" and "Sunk-enemy action". The buoy signal can be changed in seconds, it's a simple lever switch that normally sits set on "accident".
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Simple and I like it. But with how things are these day we will need more "flexible" post-mortem actions. Plus, do the buoys transmit back or must the SAR guys collect the message from it on-site? I'd prefer a prompt strike on the enemy over waiting days for a speech and nothing after.
Scott Kenny said:
It's arguable that the Outer Space Treaty has already been violated by Russia and possible China.
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Arguably so, but the US lacks the political will to say "hey, here are hard evidences the other two broke this treaty, so we are leaving too". Against dictators you need to play hardball.
 
VishnuOsiris said:
What is the point of deterrence if the enemy moves audaciously and there is no retaliation? To your point, I think the response would have to be nuclear on principle. On this line of thinking, I can foresee an attack on a CSG provoking a nuclear response. Perhaps not instantly, but I think the train has already left the station in this scenario. Call me dramatic, but I believe escalation dominance is key.
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The thing with irrational actors is that they believe they can get away with anything. Would criminals feel deterred if we implement the death penalty again? We need a robust ISR apparatus to support flexible responses and further out, preemptive strikes. The best way to fix a problem is to never let it happen in the first place. To that end, space basing is quite suitable. The enemy preps a couple of TELs to sucker punch your CSG, deorbit a warhead right onto them.
 
yeetmahboi said:
The thing with irrational actors is that they believe they can get away with anything. Would criminals feel deterred if we implement the death penalty again? We need a robust ISR apparatus to support flexible responses and further out, preemptive strikes. The best way to fix a problem is to never let it happen in the first place. To that end, space basing is quite suitable. The enemy preps a couple of TELs to sucker punch your CSG, deorbit a warhead right onto them.
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With regard to the proliferation of persistent ISR, if one has zero intention on using your nuclear deterrent in any capacity, unless the enemy has already nuked you and you seek retaliation, what is the value of the nuclear enterprise? Why have a nuclear triad? Why not SSBN only? My subjective issue is, given the cost of the collective nuclear deterrent to the taxpayer; why bother investing in them, unless you have no problem pulling the trigger?

Regarding deterrence, my thinking is Persistent/Overhead ISR > Nuclear. I'm looking at this from a very 1950s POV of "is there any difference between firebombing and atomic?" And "Bigger bang for the Buck." Given this mentality, I understand the investment. The mentality being "firebombing/atomic = good." The US has a First Strike policy... but does it really?

IMO this hasn't been the case since ~Vietnam. If this is a relic of past thinking, so be it and divest in land-based Sponges. Interception in orbit seems like the way, all things considered, and more aligned with what they are building overhead anyway. No disrespect to the Sentinel.
 
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The land based force in silos represents a force that an enemy could not engage without an overwhelming attack on the continental US that would be quickly interpreted as such. Launch on warning is still an option. Silos storage is also very inexpensive from a maintenance and manpower point of view. The Sentinel program is only expensive because the infrastructure was left to rot. After a refresh, it should be very inexpensive to maintain and provide plenty of deterrent value. The idea that it only serves as a sponge assumes that is what the enemy would target and that launch on warning is not an option.
 
yeetmahboi said:
Simple and I like it. But with how things are these day we will need more "flexible" post-mortem actions. Plus, do the buoys transmit back or must the SAR guys collect the message from it on-site? I'd prefer a prompt strike on the enemy over waiting days for a speech and nothing after.
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Radio in the buoy screaming to everyone in range. Kinda like a ship's EPIRB, but a little fancier.
 
Scott Kenny said:
Radio in the buoy screaming to everyone in range. Kinda like a ship's EPIRB, but a little fancier.
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Wasn't this beacon basically shown in operation at the beginning of Jame's Cameron's film "Abyss" when the SSBN collided with a seamount and sank?
 
NMaude said:
Wasn't this beacon basically shown in operation at the beginning of Jame's Cameron's film "Abyss" when the SSBN collided with a seamount and sank?
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Been a very long time since I watched Abyss, but I believe so. There's actually two of them, one port side just aft of the sail and the other starboard side at the end of the turtleback.
 
Dilandu said:
They are cheap, and decoy silos could easily be constructed to confuse enemy about the ICBM real numbers and placement.
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This is a brave assumption given how the United States builds things, or rather, doesn't. In theory it would be simple, but the MX debacle showed why it was impossible, and that hasn't changed given Sentinel chose to reuse silos as well. No doubt they did an analysis of alternatives and found that building new silos would breach $100 billion or whatever their initial target budget was.
 
Kat Tsun said:
This is a brave assumption given how the United States builds things, or rather, doesn't. In theory it would be simple, but the MX debacle showed why it was impossible, and that hasn't changed given Sentinel chose to reuse silos as well. No doubt they did an analysis of alternatives and found that building new silos would breach $100 billion or whatever their initial target budget was.
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As I said, adopt the "sealed round" approach - in which silo is merely a concrete shelter for a missile, sealed inside the launch container. It would reduce silo cost greatly.
 
Dilandu said:
As I said, adopt the "sealed round" approach - in which silo is merely a concrete shelter for a missile, sealed inside the launch container. It would reduce silo cost greatly.
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This was considered for Peacekeeper and found to be too expensive, time consuming and costly to construct. Retrofitting the Minuteman silo was done instead, to include the launch container support. It can easily be done.

Even excluding the somewhat awkward method incorporating TELs running around a series of horizontal shelters, the actual cost for Racetrack was in the environmental studies, the acquisition of land permits, the approval of forms, and the ultimate granting of funding without harm to exotic species or strange creatures that the Bureau of Land Management and Department of the Interior desires above holes in the ground dug for the Department of Defense.

At the rate America's economy is headed it seems like space basing warheads will be cheaper than silos. Even Ground-Based Interceptor is running into this problem where its being overshadowed by high performance SLVs and low launch costs compared to the mass of a Brilliant Pebble.
 
Josh_TN said:
Space basing nuclear warheads is an incredibly destabilizing idea. If some other country begins doing so, the U.S. will hand choice but to respond, but it is a road best avoided if possible.
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Well, if the warhead on high orbit, they aren't very destabilizing - the long delivery time (hours/days) and easy observation made them totally unsuitable for any kind of first strike (i.e. making them a purely retaliation weapon).
 
Josh_TN said:
Space basing nuclear warheads is an incredibly destabilizing idea. If some other country begins doing so, the U.S. will hand choice but to respond, but it is a road best avoided if possible.
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How technically feasible would it be for any advancing nation to send a spacecraft to grab some warheads from orbit?
 
Dilandu said:
Well, if the warhead on high orbit, they aren't very destabilizing - the long delivery time (hours/days) and easy observation made them totally unsuitable for any kind of first strike (i.e. making them a purely retaliation weapon).
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No one is building a high orbit RV and investing in all the extra money and launch capacity that would entail. And such a system is much more vulnerable to an anti satellite weapon than a terrestrial warhead is to an ABM.
 
LEO warheads give almost no reaction time for anyone involved while at the same time are impossible to hide, making them vulnerable to attack in a way that does not threaten the host country at all. I cannot think of a more destabilizing idea humanity could invent.
 
VishnuOsiris said:
What is the point of deterrence if the enemy moves audaciously and there is no retaliation?
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'The' enemy? Which enemy? In a scenario where an SSBN is lost through foul play, the launch authority is going to need very very convincing evidence as to who did it before choosing ICBMs as a response. The fear of a false-flag, or simply an accident, is substantial.

That emphasises the inflexibility of silo ICBMs: they need 110% certainty before use in a World where you'll be lucky to get 90%. Once they fly you've gone beyond nuclear war-fighting to the final level.
 
uk 75 said:
Can I ask a stupid question?
If Trident missiles are accurate enough is the only reason for a land based missile to have a heavier payload?
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D-5s have more throw weight than the Minuteman. The reason for land-based is to not have all your eggs in one basket. It also raises the threshold for an attack. Nuking a country's homeland is going to get a much more dramatic response than sinking an SSBN.
 
Big_Zukini said:
How technically feasible would it be for any advancing nation to send a spacecraft to grab some warheads from orbit?
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Doable, if they let you. Anybody who parks nukes in orbit is going to have cameras onboard to monitor the situation.
 
Josh_TN said:
No one is building a high orbit RV and investing in all the extra money and launch capacity that would entail.
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Technically it's not much harder. Especially considering the low cost of modern launches.

Josh_TN said:
And such a system is much more vulnerable to an anti satellite weapon than a terrestrial warhead is to an ABM.
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Yes, but there is a catch - the anti-satellite weapon, launched from Earth or low orbit, would took hours, maybe days, to reach the warheads. And its direction would be pretty obvious. While the HEO warheads are vulnerable to attack, they are not vulnerable to sudden attack.
 
Hanse said:
Doable, if they let you. Anybody who parks nukes in orbit is going to have cameras onboard to monitor the situation.
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Simply shooting them down would be the easier option. Then what?
 
Dilandu said:
Technically it's not much harder. Especially considering the low cost of modern launches.


Yes, but there is a catch - the anti-satellite weapon, launched from Earth or low orbit, would took hours, maybe days, to reach the warheads. And its direction would be pretty obvious. While the HEO warheads are vulnerable to attack, they are not vulnerable to sudden attack.
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Technically it’s feasible; practically it is vastly more expensive to put something in high orbit along with all of the fuel necessary to deorbit it.

The default setting will be that ASAT capability is in every orbital plane very soon. Destroying or even recovering a warhead would be quite possible with little warning. Plus, given warning, what would be the response? Detonation? Deorbit? What is the defensive mode for the RV? Are you willing to start a nuclear war over an ASAT incident?
 
Josh_TN said:
Technically it’s feasible; practically it is vastly more expensive to put something in high orbit along with all of the fuel necessary to deorbit it.
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Well, Falcon-9 Block 5 could launch about 5.800 kg on GTO. More than enough for a bus, several warheads, and retro-rocket booster (since the system is space-based, we could afford to use storable liquid-fuel and get more specific impulse than solid fuel could).

For example: let's use the old "Chevaline" missile bus for our calculations (there are a lot of data for it). It's about 318 kg fueled, and designed for 400 kg payload (warheads, decoys, chaffs, ect.). So we could safely fit three W76 warheads on it, and have enough mass for decoys.

Extracting 750 kg of payload mass from 5800 kg allowance, we are left with about 5 tons for propulsion. Let's assume that we use RD-864 hypergolic rocket engine, with a specific impulse of 300 s and dry mass of 200 kg. Let's also assume that tanks, frames, ect. are about 800 kg of total mass.

So we are left with 4000 kg of propellant for a 1800 kg of everyting else, and we have 300 s ISP engine. We could have delta-v supply around 3.4 km/s - more than enough for de-orbiting and even some maneuvering.
 
Josh_TN said:
Launch on warning is still an option. Silos storage is also very inexpensive from a maintenance and manpower point of view.
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These are great points I completely overlooked in my "defund the Sentinel" campaign. It's a shame given these facts that the Prompt Global Strike conventional ICBM never got off the ground, granted for clear destabilizing reasons.
 
Dilandu said:
Well, Falcon-9 Block 5 could launch about 5.800 kg on GTO. More than enough for a bus, several warheads, and retro-rocket booster (since the system is space-based, we could afford to use storable liquid-fuel and get more specific impulse than solid fuel could).

For example: let's use the old "Chevaline" missile bus for our calculations (there are a lot of data for it). It's about 318 kg fueled, and designed for 400 kg payload (warheads, decoys, chaffs, ect.). So we could safely fit three W76 warheads on it, and have enough mass for decoys.

Extracting 750 kg of payload mass from 5800 kg allowance, we are left with about 5 tons for propulsion. Let's assume that we use RD-864 hypergolic rocket engine, with a specific impulse of 300 s and dry mass of 200 kg. Let's also assume that tanks, frames, ect. are about 800 kg of total mass.

So we are left with 4000 kg of propellant for a 1800 kg of everyting else, and we have 300 s ISP engine. We could have delta-v supply around 3.4 km/s - more than enough for de-orbiting and even some maneuvering.
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And how many LEO satellites could you have for the same cost/effort? And how much cheaper is it to build the ASAT weapon that will engage the RV, since it only has to go up not back down? What does this buy you over a silo solution?
 
Josh_TN said:
And how many LEO satellites could you have for the same cost/effort?
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LEO warheads are much worse solution; the reaction time is very short for both sides. I.e. the opponent have little time to react on your bombs (which made them a perfect first-strike weapon) and you have very little time to react on attack on your bombs (which made them poor retaliatory weapon).
 

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