Candidates for the Kalibr-M Western Europe Buster

Following articles of January 9 and 10, 2019 on Russia's plan to build 4,500 km range, 1 tonne nuclear capable warhead, sea launched Kalibr-M cruise missiles. It is the nature of medium sized missiles that if they can be sea launched then versions can be air or ground launched. Russia (Putin) is pressing for US retention of the INF Treaty mainly to prevent the return of gound launched intermediate-ranged ballistic and cruise missiles to the Russia-NATO European theater. 

As the shape of Kalibr-M isn't known I have selected 2 possible candidates.

1.  A larger than existing evolution of Russia's Kalibr cruise missile (photo above), mainly subsonic, mainly turbojet. For convenience this could be a upscale of the Kalibr's 533mm to a 650mm horizontal torpedo tube launched with a float-up mode. Keeping down to 650mm would allow Russian Kilo and all nuclear propelled submarines to mount it with less modification.

If a missile of even larger diameter were necessary Russia would need to more heavily modify its submarines with 650+mm horizontal torpedo tubes or even vertical or diagonal launch tubes. Vertical and diagonal being more suited to Akula, Oscar, Yasen or some tubes in Borei/Borey class subs.

The increase in range from Kalibr's 2,500 km range to over 4,000 km could allow Russia from Arctic Ocean and Black Sea launch points to hit much more of Western Europe (out to the UK and Spain etc). Also a ground launched version could launch from actual Russian territory with less need for forward basing in Belarus. 

To attain a 4,500 km range it may have just a one stage booster rocket that drops off when propulsion moves to the turbojet. If a nuclear warhead is desired it doesn't need to have a 1 tonne warhead because thermonuclear warheads can be just 100 kg or even smaller. 

This would fall short of Putin, INF breaking, terror weapon propaganda value. If relying on a subsonic turbojet it would have a very long, slow flight, making it easier to detect and shoot down, particularly if it transits over or into modern NATO air defences. 

2.  The multi-named P-750 (NATO: SS-NX-24 SCORPION) Meteorit-M (for Maritime-sea launch) 3М25 would look something like the air-launched version in the (photo above  - courtesy Wiki). It looks like an unmanned rocket-jet (like the 1950s US Regulus II or a ramjet SLAM missile) rather than a convenient torpedo or vertical cylinder shape for submarine launch. See Wiki https://en.wikipedia.org/wiki/Kh-80

SS-NX-24 was an unfinished project authorised in mid-1970s, part-developed in 1980s, but terminated due to strategic arms limitation treaties (including the INF) and lack of Soviet money by the late 1980s.

Kalibr-M, improvement of the SS-NX-24, specs could include:

Weight            6,380 kg 

Length            12.8 m 3M25A (12.5 m 3M25)

Diameter         0.9 m

Warhead         various HE, nuclear (200kt to < 6Mt)

Warhead         up to 1,000 kg (1 tonne)

Engine            liquid or solid rocket or ramjet, or very fast turbojet

Wingspan       5.1 m!

The SS-NX-24 was tested on a "Yankee Sidecar" modified from normal SSBN (Project 667M Andromeda class aka "Yankee SSGN"). This SSGN was a single-ship class carrying the number K-420. K-420 appeared in 1983, carrying 12 SS-NX-24 nuclear-tipped cruise missiles instead of the original ballistic missiles. The SS-NX-24 was an experimental cruise missile, with a supersonic flight regime and twin nuclear warheads. It was meant as a tri-service strategic weapon, and thus would have filled a rather different role than the anti-ship Oscar-class SSGNs. In the end, the missile was not adopted,

CONCLUSION

Significantly No. 2's (SS-NX-24) a high-supersonic, rocket, ramjet or advanced turbojet speed, may satisfy Putin's INF breaking terror weapon criteria. It provides an uncertain middle ground on the way to faster, nuclear-certain, Russian ballistic missiles.

Placing nuclear warheads on even a minority of subsonic cruise missiles may risk a nuclear response from NATO. 

However Putin may wish to intentionally raise tensions in Western Euope by re-introducing the Cold War uncertainty of nuclear armed cruise missiles. 

As the US mainland, unlike European countries, will not be under threat from nuclear cruise, Kalibr-M can help drive a wedge in already Trump damaged US-European NATO member relations. Such a wedge was present between the Reagan's US and European countries in the 1980s which was largely resolved by the INF Treaty.

Pete