I'm surprised that the Army is responsible for the GBI interceptors. I had thought those were also Air Force operated. Seems odd to designate them as Army systems.
I recently discovered some interesting cost and procurement figures for the Mk21A/W87-1 and the new AF&F for the W87 and W87-1. The procurement figures for these have some very troubling implications.
For the new Mk21A RV to be used on the Mk21A/W87-1, currently only 457 RVs (31 development, 426 production) are being purchased.
The actual costs per RV are roughly $14.4 million. Procurement costs account for $5.7 million. RDT&E accounts for the other $8.7 million.
For the new AF&F (fuze) to be used on both the Mk21/W87 and the Mk21A/W87-1, currently only 743 fuzes (88 development, 655 production) are to be purchased.
The actual costs per AF&F (fuze) are roughly $3.5 million.
Total historical production for the Mk21/W87 is either 525 or 560 warheads. I suspect the higher number is probably slightly more likely to be correct, although the lower number remains plausible. So let's assume 560 were built.
Currently, 200 Mk21/W87 warheads are deployed on Minuteman III missiles.
The exact number of remaining Mk21/W87 warheads held in reserve is unknown. One source in 2020 estimated that 340 additional warheads may be held in reserve. A certain number of warheads are destroyed during testing over time, so the reserve number should be lower than the original procurement number. 340 suggests only 20 were lost to destructive testing, which is a bit lower than I would have expected, but not entirely implausible.
So this implies the total pool of Mk21/W87 warheads is probably no more than 540 warheads in total.
With only 655 production fuzes being procured, and with 426 of them going to production W87-1 warheads, that implies only 229 fuzes will be left over for the W87 warheads.
This suggests that they do not intend to modernize the fuzes in the majority of the W87 warheads, which will result in most of the current W87 arsenal being rendered unreliable and unsuitable for future use.
It's unclear what the plan is regarding the transition between MM III and Sentinel with respect to ICBM fuze replacements and warhead swaps. One burning question is if they intend to replace the fuzes in the W87 warheads currently in use on the MM III missiles, or if they intend to only replace the fuzes in W87 warheads from the reserve force destined for use on the initial Sentinel missiles, or something else entirely.
It is clear that the W87-1 procurement will be very small, only just barely enough warheads to equip every one of the 400 Sentinel missiles with a single W87-1 warhead, with just 26 extra warheads beyond that.
This is concerning, especially when you consider that only 229 W87 warheads with new fuzes will be available for upload use.
Combined with the 26 extra W87-1 warheads, that makes for up to 255 warheads that could potentially be used for upload (although in reality, you cannot use 100% of the warheads in inventory, as a certain margin must be held in reserve to allow for maintenance and destructive testing activities).
That is an extremely limited upload capacity!
If we have 400 active missiles in the 450 hot silos, we could deploy only a maximum of 655 warheads across those 400 missiles, or an average of 1.6375 warheads per missile. Realistically, the maximum upload capacity would be lower than this due to the aforementioned issues.
If we are to retain the ability to credibly re-MIRV the Sentinel in the future (meaning at least a full 2:1 MIRV across the entire force at the baseline 400 missile deployment force level), then Congress must either:
Edit: There is a chance that the Mk21A/W87-1 AF&F order will be procured separately from the Mk21/W87-0 order. It is possible that the current contract is intended solely for the Mk21/W87-0.
Interestingly, earlier versions of this contract had a slightly higher number of fuzes set to be procured, and were seemingly intended to be procured solely for use on the Mk21/W87-0. Later versions mostly refer to it as the Mk21/W87 instead of using the W87-0 designation, and have a slightly lower number of fuzes to be procured, which creates ambiguity regarding if the contract is meant to cover the new Mk21A/W87-1 warheads, or if they will be splitting the order for fuzes for those new warheads into an entirely separate contract (which would be hideously inefficient from a cost perspective, but is possible).
The absurdly convoluted history of the W78-1 LEP // IW1 // W78/88-1 LEP // W87-1 program makes this hard to track and even harder to analyze.
Either way, at minimum there is still a lack of clarity on the exact scope of the W87-0 refurbishments, and it's also very clear that the total procurement of W87-1 is much lower than many of us would have expected.
The total procurement numbers for the W87-1 are actually so low that I am questioning if they are intentionally planning on keeping Sentinel as a mixed force of W87-1 and W87-0 in the long term in order to mitigate risks from having only a single type of warhead deployed and offer a more diverse range of yield options, similar to how the current force is a mixture of the W87 and the W78, or how it was previously a mixture of the W78 and the W62.
I'm doubtful that 426 warheads would actually be enough to deploy one warhead on every missile and keep them operating for the next 40 years, as this number is likely not enough to allow for attrition due to destructive testing over the course of 40 years while still keeping a sufficient number of warheads in reserve to allow for routine maintenance activities (as well as a sufficient reserve buffer for a eventual LEP).
So it looks like the intention is likely to operate the Sentinel with a mixed force of W87-1 and W87-0 in the long term, as that's the only way to ensure there's enough of a buffer available for destructive testing, maintenance, and LEPs.
It's either that or they are anticipating a force reduction below 400 deployed missiles, and the later no longer seems plausible in today's world.
I recently discovered some interesting cost and procurement figures for the Mk21A/W87-1 and the new AF&F for the W87 and W87-1. The procurement figures for these have some very troubling implications.
For the new Mk21A RV to be used on the Mk21A/W87-1, currently only 457 RVs (31 development, 426 production) are being purchased.
The actual costs per RV are roughly $14.4 million. Procurement costs account for $5.7 million. RDT&E accounts for the other $8.7 million.
For the new AF&F (fuze) to be used on both the Mk21/W87 and the Mk21A/W87-1, currently only 743 fuzes (88 development, 655 production) are to be purchased.
The actual costs per AF&F (fuze) are roughly $3.5 million.
Total historical production for the Mk21/W87 is either 525 or 560 warheads. I suspect the higher number is probably slightly more likely to be correct, although the lower number remains plausible. So let's assume 560 were built.
Currently, 200 Mk21/W87 warheads are deployed on Minuteman III missiles.
The exact number of remaining Mk21/W87 warheads held in reserve is unknown. One source in 2020 estimated that 340 additional warheads may be held in reserve. A certain number of warheads are destroyed during testing over time, so the reserve number should be lower than the original procurement number. 340 suggests only 20 were lost to destructive testing, which is a bit lower than I would have expected, but not entirely implausible.
So this implies the total pool of Mk21/W87 warheads is probably no more than 540 warheads in total.
With only 655 production fuzes being procured, and with 426 of them going to production W87-1 warheads, that implies only 229 fuzes will be left over for the W87 warheads.
This suggests that they do not intend to modernize the fuzes in the majority of the W87 warheads, which will result in most of the current W87 arsenal being rendered unreliable and unsuitable for future use.
It's unclear what the plan is regarding the transition between MM III and Sentinel with respect to ICBM fuze replacements and warhead swaps. One burning question is if they intend to replace the fuzes in the W87 warheads currently in use on the MM III missiles, or if they intend to only replace the fuzes in W87 warheads from the reserve force destined for use on the initial Sentinel missiles, or something else entirely.
It is clear that the W87-1 procurement will be very small, only just barely enough warheads to equip every one of the 400 Sentinel missiles with a single W87-1 warhead, with just 26 extra warheads beyond that.
This is concerning, especially when you consider that only 229 W87 warheads with new fuzes will be available for upload use.
Combined with the 26 extra W87-1 warheads, that makes for up to 255 warheads that could potentially be used for upload (although in reality, you cannot use 100% of the warheads in inventory, as a certain margin must be held in reserve to allow for maintenance and destructive testing activities).
That is an extremely limited upload capacity!
If we have 400 active missiles in the 450 hot silos, we could deploy only a maximum of 655 warheads across those 400 missiles, or an average of 1.6375 warheads per missile. Realistically, the maximum upload capacity would be lower than this due to the aforementioned issues.
If we are to retain the ability to credibly re-MIRV the Sentinel in the future (meaning at least a full 2:1 MIRV across the entire force at the baseline 400 missile deployment force level), then Congress must either:
- Increase the size of the order for W87/W87-1 fuzes (which MUST be done before production ends, otherwise they would have to start a new order at a MUCH higher cost) in order to allow life extending more of the W87 arsenal. This could eventually offer up to 340 additional warheads, enough to do 2:1 MIRV across the entire Sentinel fleet.
- Increase the size of the order for Mk21A RVs (which MUST be done before production ends, otherwise they would have to start a new order at a MUCH higher cost) and increase the number of W87-1 warheads manufactured (which would take a while do given the extremely slow pace of pit production, the repeated delays in scaling up pit production, the repeated delays in bringing the secondary pit production facility online, and the current backlog of around 425 pits). This could offer an unlimited number of additional warheads, but it would take much longer to produce them.
- Do both of the previous two steps (the ideal option).
- Have the Sentinel adapted to be able to carry the W78 and have the W78 go through another life extension program. Given the safety issues with the W78, the fact that it's unlikely Sentinel is already capable of carrying the W78, the fact that another W78 LEP would not be a cheap or fast process, and the Air Force's repeatedly stated strong desire to phase out use of the W78, this would not be a cheap option, nor would it be a very wise decision from a long term perspective, and the Air Force would likely strongly oppose any attempt to go through with this option.
Edit: There is a chance that the Mk21A/W87-1 AF&F order will be procured separately from the Mk21/W87-0 order. It is possible that the current contract is intended solely for the Mk21/W87-0.
Interestingly, earlier versions of this contract had a slightly higher number of fuzes set to be procured, and were seemingly intended to be procured solely for use on the Mk21/W87-0. Later versions mostly refer to it as the Mk21/W87 instead of using the W87-0 designation, and have a slightly lower number of fuzes to be procured, which creates ambiguity regarding if the contract is meant to cover the new Mk21A/W87-1 warheads, or if they will be splitting the order for fuzes for those new warheads into an entirely separate contract (which would be hideously inefficient from a cost perspective, but is possible).
The absurdly convoluted history of the W78-1 LEP // IW1 // W78/88-1 LEP // W87-1 program makes this hard to track and even harder to analyze.
Either way, at minimum there is still a lack of clarity on the exact scope of the W87-0 refurbishments, and it's also very clear that the total procurement of W87-1 is much lower than many of us would have expected.
The total procurement numbers for the W87-1 are actually so low that I am questioning if they are intentionally planning on keeping Sentinel as a mixed force of W87-1 and W87-0 in the long term in order to mitigate risks from having only a single type of warhead deployed and offer a more diverse range of yield options, similar to how the current force is a mixture of the W87 and the W78, or how it was previously a mixture of the W78 and the W62.
I'm doubtful that 426 warheads would actually be enough to deploy one warhead on every missile and keep them operating for the next 40 years, as this number is likely not enough to allow for attrition due to destructive testing over the course of 40 years while still keeping a sufficient number of warheads in reserve to allow for routine maintenance activities (as well as a sufficient reserve buffer for a eventual LEP).
So it looks like the intention is likely to operate the Sentinel with a mixed force of W87-1 and W87-0 in the long term, as that's the only way to ensure there's enough of a buffer available for destructive testing, maintenance, and LEPs.
It's either that or they are anticipating a force reduction below 400 deployed missiles, and the later no longer seems plausible in today's world.
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