Thread by @DuitsyWasHere

1/12 Continuing from the previous thread on Soviet nuclear turbojet research, I will now give a quick overview of Soviet nuclear ramjet research.

This thread is a bit longer, since the story is rather convoluted.

(Previous thread linked below)

https://twitter.com/DuitsyWasHere/status/1161690240500637696

2/ Soviet nuclear ramjet research can mostly be traced back to OKB-670, originally led by Mikhail Bondaryuk.

In the 1950's, OKB-670 focused on conventional ramjets for surface-to-air missiles and experimental intercontinental cruise missiles.

3/ Among them was the Lavochkin bureau’s La-350 “Burya” – a massive missile with a 97 ton launch weight. OKB-670 was also tasked to design a nuclear ramjet for an even larger missile, item 375.
In his 1958 book on ramjet design, Bondaryuk devotes a chapter to nuclear ramjets.

4/ However, the successful demonstration of ICBMs (and Lavochkin’s death in 1960, among other factors) largely ended the need for very large ramjets (though there was a project 1964-65 for an ICBM with a solid fuel ramjet).

OKB-670 needed to find a new role.

5/ In the 1960’s, OKB-670 developed missile power supplies and was closely involved in several nuclear projects, including a nuclear rocket engine for prospective Korolev rockets, and reactors for satellites, like the BR-5A and BES-5.

(Yes, I know the last picture is a TOPAZ)

6/ In 1967, OKB-670 was renamed Krasnaya Zvezda. Rosatom’s Krasnaya Zvezda is a direct descendant of this organization. redstaratom.ru

7/ Bondaryuk’s death in 1969 had a substantial effect on OKB-670. Most of the ramjet team left; many went to TMKB Soyuz and were involved in development of the engine for the Moskit anti-ship missile.

8/12 In 1978, a new design bureau for ramjets was formed at the pre-existing Scientific Research Institute for Thermal Processes (NIITP). Most of the original ramjet team from OKB-670 would eventually end up at this bureau, which was named "Plamya" (flame).

9/ In addition to the development of conventional ramjets for the Yakhont (Oniks/Brahmos) missile and other projects, during the late 1970’s, the bureau also conducted research for a small nuclear ramjet for a possible 15-20 ton cruise missile.

10/ This nuclear ramjet project was cancelled for environment reasons, including the inability to conduct full-range test flights. I could find very little information about the missile, although it appears there were never any tests conducted.

11/12 Things, however, did not end well for Plamya. They spent the 90’s getting moved around and absorbed by other organizations, and were eventually dissolved in 2004.

12/12 Again, I don’t think Burevestnik is ramjet-powered; I just thought this part of Soviet nuclear aircraft propulsion also deserved some coverage.

Actually, there is one last interesting thing...

Near the end of his book, in a chapter on potential future developments, Bondaryuk gives a short discussion on using isotopes to power a ramjet.

In addition to handling difficulties, the inability to regulate heat production creates structural and operational problems.

Bondaryuk suggests throttling the engine by varying the critical area of the nozzle (since the heat can't regulated), but has no advice for the other problems.

Have a nice weekend!