R-3A

Russian intermediate range ballistic missile. So much new technology was involved for the R-3 that it was deemed necessary to build an R-3A intermediate experimental rocket, based on the R-2. This would be flown to test new construction methods, guidance systems, and high energy propellants. The R-3A was specified in 1949 to have a 900 to 1000 km range with a payload of 1530 kg; an unfueled mass of 4100 kg; 20,500 kg of propellants; and a lift-off thrust of 40 metric tons. The R-3A could also serve as a prototype for a more modest IRBM. Flight tests of the R-3A were scheduled for October 1951.

The R-3 itself was cancelled when difficulties were encountered in engine development and the decision was made to proceed directly to the R-7 ICBM. During its development the range of the R-3A had settled on 935 km with only a 500 kg payload. It was cancelled in October 1951 without ever flying, with the technology being applied to the R-5 and R-11 missiles. The Russians have been very reluctant to reveal the configuration of the R-3A. It seems likely that it was actually a subscale version of Groettrup's G-4 design, and formed the technical basis for both the R-7 ICBM and N1 super launch vehicle.

Maximum range: 900 km (550 mi).

Stage Data - R-3A

• Stage 1. 1 x R-3A. Gross Mass: 19,900 kg (43,800 lb). Empty Mass: 3,500 kg (7,700 lb). Thrust (vac): 434.400 kN (97,657 lbf). Isp: 235 sec. Burn time: 83 sec. Isp(sl): 210 sec. Diameter: 1.65 m (5.42 ft). Span: 3.50 m (11.40 ft). Length: 20.00 m (65.00 ft). Propellants: Lox/Alcohol. No Engines: 1. Engine: RD-102. Status: Development 1951. Comments: Further incremental upgrade of R-2. Payload 500 kg. Range 935 km. Developed from 1949 to October 1951. Cancelled, work combined with 8K14 development.