Manufacturer Name: RD-0410. Government Designation: 11B91. Designer: Kosberg. Developed in: 1965-94. Application: Experimental nuclear engine. Propellants: Nuclear/LH2Thrust(vac): 3,600 kgf. Thrust(vac): 35.30 kN. Isp: 910 sec. Burn time: 3,600 sec. Mass Engine: 2,000 kg. Diameter: 1.6 m. Length: 3.5 m. Chambers: 1. Country: Russia. Status: Developed 1965-94. First Flight: 1985. References: 98 , 309 . Comments: Nuclear thermal rocket engine. Propellant LH2. Developed from 1965 through 1980s. Tested at Semipalatinsk test range in 1980s and was "the only operational nuclear engine in the USSR".