R-56

The full designs of the UR-700 and the R-56 have not been fully revealed, though it is now possible to speculate with accuracy what they may have been like [7]. Like the N-1, the R-56 offered a minimalist lunar mission, with a lunar-bound payload of 30 tonnes. Chief designer was Mikhail Yangel. Born in Irkutsk on 25th October 1911 (os), he was a graduate of the Moscow Aviation Institute and after the war worked in Korolev’s OKB-1. In 1954, he was given his own design institute, OKB-586 in Dnepropetrovsk. A model of the R-56 now appears in the company museum and sketches have been issued. The R-56 was a three-stage rocket, 68 m long, each cluster 6.5 m in diameter. To get from the Ukraine to Kazakhstan, it would be transported by sea – but this could be done on barges from the Dnepropetrovsk factory on the inland waterway system of the Soviet Union via the Syr Darya to Tyuratam.

The principal difference between the N-1 and the R-56 was the use of engines. For the R-56, Valentin Glushko’s OKB-456, the old Gas Dynamics Laboratory, devel­oped large, high-performance engines called RD-270. For many years, it had been assumed that the Soviet Union had been unable to develop such engines, but this was not the case. Unlike the American engines, which used liquid oxygen and liquid hydrogen, Glushko used storable fuels. His engines used unsymmetrical dimethyl methyl hydrazine (UDMH) and nitrogen tetroxide, producing a vacuum thrust of between 640 and 685 tonnes, a specific impulse of 322 sec and a pressure of 266 atmospheres in its combustion chamber. Each RD-270 weighed 4.7 tonnes, was 4.8 m tall and could be gimballed. Valentin Glushko managed to build 22 experi­mental models of the RD-270 and 27 firings were carried out in the course of October 1967 to July 1969, all showing great promise. Three engines fired twice and one three times.

4.85 m 3.3m

266 atmospheres

3,056

322 sec

4.77 tonnes (dry) 5.6 tonnes (fuelled)

In the event, the R-56 did not turn out to be a serious competitor. There is some suggestion that Yangel saw the damage being done by the rivalry within the Soviet space industry and did not wish to press a third project that would divert resources even further. Authority to develop the R-56 seems to have been given by the govern­ment in April 1962, but a subsequent government decision in June 1964 ordered a cessation of work.