Relationship between R-36/Tskylon and R-36M/Dnepr

[Nicolas PILLET]

Article for this one:
http://www.nasaspaceflight.com/2015/03/russias-dnepr-rocket-kompsat-3a-mission/

I don't agree with historical part of this article. Dnepr is not derived from R-36 : it is derived from R-36M UTTKh (not UTTH as written in the article), which has almost no link with R-36 (althought its name could suggest the opposite). Different engines, different design, etc.

The launcher derived from R-36 is Tsyklon, which is retired since 2009.

[Danderman]

Article for this one:
http://www.nasaspaceflight.com/2015/03/russias-dnepr-rocket-kompsat-3a-mission/

I don't agree with historical part of this article. Dnepr is not derived from R-36 : it is derived from R-36M UTTKh (not UTTH as written in the article), which has almost no link with R-36 (althought its name could suggest the opposite). Different engines, different design, etc.

The launcher derived from R-36 is Tsyklon, which is retired since 2009.

Nicolas is correct.

In the late 1970s, the USSR played some games with designations of missiles to confuse Western analysts - one such maneuver was calling the Dnepr "RD-36M" to make it appear that it was a modified R-36 missile, which it wasn't.  The throw weight of Dnepr compared with Tsiklon was 30% greater, due to a completely different design, which happened to fit into R-36 silos.

[Nicolas PILLET]

designations of missiles to confuse Western analysts

And it still works !!

[Galactic Penguin SST]

Hmm I thought that while the R-36M was a new design, the engines have heritage from the ones on the R-36 (despite not exactly a direct evolution)?

[Galactic Penguin SST]

Hmm I thought that while the R-36M was a new design, the engines have heritage from the ones on the R-36 (despite not exactly a direct evolution)?

Bump - anyone knows how much commodity are there between these two designs?

[Danderman]

Hmm I thought that while the R-36M was a new design, the engines have heritage from the ones on the R-36 (despite not exactly a direct evolution)?

Not at all.

The engine design for Cyclone was initiated in  1959 as a two chamber, low ISP, 90 ton thrust system.

The single chamber Dnepr engines (RD-263) were developed in the 1970s, with much higher ISP. Each engine produces about 250,000 lbs of thrust, or ~ 125 metric tons, and the 4 engines operate together as the RD-264.   It is possible that RD-263 was somehow derived from the earlier Cyclone engines, but I don't see any commonality.

The second stage is powered by the RD-0255 which I believe to be a derivative of the engine used for the Proton 3rd stage, which, in turn, was related to the UR-200 2nd stage.

The SS-18 could be described as a UR-200 with a much more powerful first stage, a comparable second stage, and a powered MIRV bus.

I can't see any commonality with R-36, except that they had similar dimensions and were produced in the same factory.

[Dmitry_V_home]

Article for this one:
http://www.nasaspaceflight.com/2015/03/russias-dnepr-rocket-kompsat-3a-mission/

I don't agree with historical part of this article. Dnepr is not derived from R-36 : it is derived from R-36M UTTKh (not UTTH as written in the article), which has almost no link with R-36 (althought its name could suggest the opposite). Different engines, different design, etc.

The launcher derived from R-36 is Tsyklon, which is retired since 2009.

Nicolas is correct.

In the late 1970s, the USSR played some games with designations of missiles to confuse Western analysts - one such maneuver was calling the Dnepr "RD-36M" to make it appear that it was a modified R-36 missile, which it wasn't.  The throw weight of Dnepr compared with Tsiklon was 30% greater, due to a completely different design, which happened to fit into R-36 silos.

More likely, the R-36M index was urged to confuse the political and financial management of the USSR. As this management with bigger hunting allocated money for modernization of old equipment, but not for development new. Similar "card trick" was done with the Tu-22М plane (Backfire) which was similar to original Tu-22, "as the fork is similar
on a bottle".

[edkyle99]

R-36 and R-36M appear to be the same diameter.  That's about all they share.

 - Ed Kyle

[Danderman]

R-36 and R-36M appear to be the same diameter.  That's about all they share.

 - Ed Kyle

So they fit in the same silos.

[zubenelgenubi]

R-36 and R-36M appear to be the same diameter.  That's about all they share.

 - Ed Kyle

So they fit in the same silos.

Wasn't this part of the attempted ruse?  Use of the same silos implied that the new missile was derived from the old missile type that used the silos?  When in fact, it did not?

One intention was fooling USA/NATO intelligence agencies into incorrect technical assumptions about the new missile?

Was the misleading designation also an attempt to get a new missile installed and stretch/subvert limitations under the SALT/SALT II treaties?  Or not?

(Another advantage was not having to dig a bunch of new holes?)

Sorry if I'm re-stating something obvious to others--I just wanted to get the concept(s) clear for myself.

[Danderman]

Not exactly.

Re-use of silos was also done with R-16 and R-36, so fooling the USA was not the prime consideration.

However, the designation of "R-36M" indeed was probably a ruse, as the definition of a "new" ICBM under SALT was less than 15% new design.

 

IIRC, R-36 and R-36M used different oxidizers,  with SS-18 using N2O4, whereas SS-9 (R-36) used nitric acid.

Clearly, DoD was not fooled by the R-36 naming conventions as they gave SS-18 its own designation, rather than "Mod" number.

However, SS-10 fooled DoD completely.