The R-5 was originally a development of OKB-1 as a single-stage missile with a detachable warhead reentry vehicle. The R-5M was a nuclear armed missile – the first nuclear missile to be deployed by the Soviet Union – with greater payload and weight but better reliability than its predecessor. The R-5M gave the Soviet Union the ability to target many strategic targets in Europe. The R-5M entered service on 21 May 1956 (retired in 1967), and in 1959 was installed at Vogelsang, Zehdenick in East Germany - the first Soviet nuclear missile base outside of the USSR.