In April 2010, Rosnadzor, the regulatory body of the Russian government, issued a directive that ordered an environmental assessment of a very interesting project - "construction of facilities of the A35-71 launcher with a space head section at the Object 307 site ("создание комплекса ракеты-носителя А35-71 с космической головной частью на объекте 370"). This very brief phrase in a routine bureaucratic document raises quite a few questions - what are exactly the "A35-71 launcher", its "space head section", and "Object 370"? The short answer is that we don't really know. But we could guess (with a lot of help from my readers and some combing through the internet).
Object 307 is apparently a large construction project at a site 7 km away from Yasnyy. There are two R-36M silos of the Dombarovskiy missile division that are located at that distance from Yasnyy. One, to the north of the town, has been converted to the Yasnyy space launch site that supports launches of the Dnepr system, so it is already in use. The other one, to the east, is just a regular silo, which looks more suitable for a new project. The construction at the Object 370 site appears to be quite intensive - the site includes an "experimental testing base" as well as a number of buildings and extensive support infrastructure, including a new railroad link to Yasnyy.
The most interesting part of the construction activity appears to involve conversion of the old R-36M silo - SKTB-16, a design bureau with a long history of work on ICBM silos, mentions "conversion of P718 facility to P771 facility" as one of its projects. Now, P718 is apparently the 15P718, a standard R-36M silo; the missile itself has an index 15A18. So, P771 most likely refers to a silo that would house the A35-71 launcher, whatever it is (we'll get to the A35-71 in a moment). I couldn't find a direct connection between the SKTB-16 work and the Object 370, but there are not very many R-36M silos that could be converted. The Rocket Forces has kept some of these silos - there may be some in Uzhur and there are definitely a few in Dombarovskiy. Given the level of activity in Dombarovskiy, it is likely that the Object 370 is indeed the place where the silo conversion takes place.
The index A35-71 probably refers to some modification of the 15A35 missile system, otherwise known as UR-100NUTTH or SS-19. The index seems to suggest that the missile itself has not changed very much and the most important modification is the new "space head section" (космическая головная часть). I must admit it is really no more than a guess, but it seems to be reasonably consistent with other bits and pieces of information. So, what is this new "head section" and why the missile that carries it could not be deployed in old UR-100NUTTH/SS-19 silos?
The SKTB-16 report mentions that the conversion is done as part of the Project 4202 (в интересах темы "4202"). This is something new we could work with. As it turns out, Project 4202 is "one of the most important projects" of NPO Mashinostroyeniya - the old Chelomey design bureau that designed the UR-100NUTTH missile. A search through the NPOMash site reveals that this work involves manufacturing of something that has several sections of a fairly complex shape and uses some non-metallic and anti-radar materials - not a bad candidate for the new "head section" of the "A35-71 launcher."
A few more dots to connect - in 2004, NPOMash demonstrated what was described as a "hypersonic maneuverable warhead" that was flown on a UR-100NUTTH missile. Could that be the new "space head section"? I would say it's quite possible. It is a bit strange that it would be described as a "space" warhead, but it does seem to travel through space for a significant part of its flight, so it won't be much of a stretch. If this is indeed what the Project 4202 is about, it explains why its deployment requires modification of a silo - as I understand, this warhead is rather big, so it won't fit into a standard UR-100NUTTH silo. The R-36M silos are much deeper - the missile is about 9 meters longer than UR-100NUTTH - so it could probably accommodate the bigger "head section" as well. But the silos may need some modification - unlike R-36M family, UR-100NUTTH is a "hot launch" missile. I'm not sure this would be the main reason why the conversion is necessary, though - there might be others.
The "hypersonic warhead" is not the only possible explanation for the activity at the Object 370. The description of the A35-71 as a "launcher" (ракета-носитель) seems to imply that it would be used to deliver payload into space. I thought that the Naryad-V ASAT system is a reasonably good candidate as well - it was supposed to be deployed on UR-100NUTTH missiles. But a colleague who spent some serious time researching Project 4202 assured me that it's not Naryad-V. Another argument against Naryad is that an ASAT kill vehicle is unlikely to need anti-radar coating or a complex shape. Also, there is a possibility that Object 370 has nothing to do with the Project 4202.
Another question about this whole enterprise is whether it makes sense to develop a new payload for the UR-100NUTTH missile, which will turn 40 years old in a few years. One possible answer to that is that Russia may be planning to resume production of UR-100NUTTH or build a derivative of this missile - there are signs that something like this is under consideration. It's also possible that the new payload could be deployed on Topol-M, although this does not seem to be part of the current plan.
If all this activity is indeed about deployment of a new system that would carry some kind of a "space head section" it could raise a few questions about whether this new system should be covered by the New START treaty. The treaty defines a ballistic missile as a "a missile that is a weapon-delivery vehicle that has a ballistic trajectory over most of its flight path." This definition would probably exempt some of the systems that the United States wants to deploy as part of its Prompt Global Strike program. The U.S., of course, would argue that these systems should not be considered "new kinds of strategic offensive arms" as they do not meet the definition of the treaty - they are not ballistic missiles, for example. Russia might be happy to agree with that position, since that would leave its own systems outside of the treaty as well. But unlike the U.S., Russia might want to deploy them with nuclear warheads - this would probably give the United States a pause.
I should say I remain quite skeptical about all these fancy systems - it is unlikely that in terms of delivered payload or the ability to penetrate missile defenses (probably a big selling point in Russia) they would outperform ICBMs. But that's never been the point of these kind of projects anyway.
In the end, I think the long answer to the questions about Object 370, A35-71, and Project 4202 is very much similar to the short one - we don't really know. But there is something interesting (if not quite reasonable) going on at Dombarovskiy. My guess is that we'll soon hear more about it.