USAF Ballistic Missile Re-Entry Vehicles

[Yellow Palace]

Trying to identify the various USAF ballistic missile re-entry vehicles over the years. The latest one confirmed to exist is the Mk-21 developed for the Peacekeeper and Midgetman missiles, but there are a few gaps:

Mk-1: Possibly W49, ablative RV, carried on Jupiter
Mk-2: W49 warhead, heat sink RV, carried on Atlas D & Thor
Mk-3: W49 warhead, ablative RV, carried on Atlas D
Mk-4: W38 warhead, carried on Atlas E/F & Titan I
Mk-5: W59 warhead, carried on Minuteman I
Mk-6: W53 warhead, carried on Titan II
Mk-7: W59 warhead, carried on Skybolt
Mk-8: Unknown
Mk-9: Unknown
Mk-10: Unknown
Mk-11: W56 warhead, carried on Minuteman II. Three variants.
Mk-12: W62 warhead, carried on Minuteman III
Mk-12A: W78 warhead, carried on Minuteman III
Mk-13: Titan II MIRV, details unknown, cancelled
Mk-14: Atlas & Titan I MIRV, details unknown, cancelled
Mk-15: Unknown
Mk-16: Previously designated Mk-12 (Heavy), cancelled in favour of Mk-17
Mk-17: 1.8 megaton warhead, 1,200lb (target 900lb, 938lb at time of cancellation) successor to Mk-11 to equip 700 Minuteman II. Cancelled.
Mk-18: 'Small enough to use in clusters', 28 on WS-120 or 7 on Minuteman III. Similar concept to Navy Mk-3, joint program hoped for but Navy choice of heatshield material unsuitable for ICBM. Cancelled.
Mk-19: Planned 'hard target killer', details unknown. Cancelled, but technology development continued under ABRES
Mk-20: Unknown
Mk-21: W87 warhead, carried on Minuteman III, Peacekeeper & Midgetman

Early plans for Minuteman required a light re-entry vehicle weighing 550lb with a 330 lb or 400lb warhead. This was cancelled in December 1958. It may account for one of the missing RVs between Mk-7 and Mk-11. A similar light - in this case 600lb) re-entry vehicle with a 400 kiloton yield was planned for Skybolt, which might account for another. As Minuteman and Skybolt both used the same 'heavy' warhead in different RVs, it seems reasonable that the same should apply for the 'light' warhead.

 

[Yellow Palace]

Mk-12: W62 warhead, carried on Minuteman III
Mk-12A: W78 warhead, carried on Minuteman III
Mk-13: Titan II MIRV, details unknown, cancelled
Mk-14: Atlas & Titan I MIRV, details unknown, cancelled

In Titan II: A History of a Cold War Missile Program, David K. Stumpf gives more detail.

The Mk-12, Mk-13 and Mk-14 were originally envisaged as non-independent MRV payloads for the respective missiles, similar in concept to the Polaris A3. Only the Mk-12 was funded, with the Mk-17 RV following later. The Mk-17 would be too heavy for use on Minuteman, but Titan II could accommodate up to seven; a six-warhead bus was proposed, achieving a range of 7,600 nautical miles with four RVs or 5,760 nautical miles with six RVs. Stumpf quotes a yield of 2 Mt and CEP of 0.3 nautical miles, giving Titan II a counterforce capability. Implementation of this proposal would have cost $278 million in R&D and $262 million to retrofit the missiles, taking 53 months.

Much of the Mk-17 history comes from the USAF's Ballistic Missile Program Histories, hosted on Ryan Crierie's website:

http://www.alternatewars.com/WW3/WW3_Documents/USAF/USAF_BM_1964-66.htm

https://www.alternatewars.com/WW3/WW3_Documents/USAF/USAF_BM_1967-68.htm

It's a shame that the 1960-1961 document, USAF Intercontinental Ballistic Missiles, Fiscal Years 1960-61, doesn't seem to be readily available online anywhere.

 

[Yellow Palace]

Early plans for Minuteman required a light re-entry vehicle weighing 550lb with a 330 lb or 400lb warhead. This was cancelled in December 1958. It may account for one of the missing RVs between Mk-7 and Mk-11. A similar light - in this case 600lb) re-entry vehicle with a 400 kiloton yield was planned for Skybolt, which might account for another.

Incidentally, I believe another derivative of this warhead - or possibly the Minuteman version unchanged - was to be used on MMRBM. The specified damage capability and CEP in GOR 161 works out as requiring a yield of 400 kilotons.