The R-11 originated from a 1951 requirement for a
ballistic missile with similar performance to the German
V-2 rocket, but half its size. With the
Wasserfall, an anti-aircraft version of the V-2, as a model, the R-11 was developed by engineer
Victor Makeev, who was then working in
OKB-1, headed by
Sergey Korolyov. The two men agreed on the use of
RG-1 as the fuel, but disagreed over which oxidizer to use, with Korolev favouring
liquid oxygen, and Makeev advocating the use of a storable but toxic oxidizer. Makeev's version, that first flew on 18 April 1953, was fitted with an
Isayev engine using
RG-1 and
nitric acid. On 13 December 1953, a production order was passed with
SKB-385 in
Zlatoust, a factory dedicated to producing long-range rockets. In June 1955, Makeev was appointed chief designer of the SKB-385 to oversee the programme and, in July, the R-11 was formally accepted into military service. ==Systems specification==