Evolution of the R-7 Evolution of the R-7 design: From left, Groettrup 'Cluster of G-4's', 1952; Korolev R-7, 1953; R-7 design for increased warhead size, 1954; R-7 as flown. 59,795 bytes. 640 x 535 pixels.

Some sources indicate the G-5 / R-15 designation was assigned to an ICBM designed by the Groettrup team. If so, it may have been the 'packet of G-4's' that was the direct ancestor of the Korolev R-7. The designation G-5 / R-15 has also been reported as that of the ramjet missile more often referred to as G-3 or R-13.

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