Bell 8247

Bell Nitric acid/UDMH rocket engine. Out of Production. Version of Agena engine for the Gemini-Agena Target Vehicle. Minimum capability of five restarts and a demonstrated capability of fifteen restarts. First flight 1963.

The Gemini-Agena Target Vehicle design was an adaptation of the basic Agena-D vehicle using the alternate Model 8247 rocket engine and additional program-peculiar equipment required for the Gemini mission. The XLR-8I-BA-13 was a liquid bi-propellant rocket engine with a minimum capability of five starts and a demonstrated capability of fifteen starts under vacuum conditions. This rocket engine consisted of the following major components:

• Thrust-chamber assembly
• Multiple-restart assembly
• Turbine-pump assembly
• Overspeed shutdown electronic-gate and cable assembly
• Turbine-exhaust duct
• Propellant manifolds
• Thrust-chamber nozzle extension

Fuel used was unsymmetrical dimethylhydrazine (UDMH); oxidizer used was inhibited red fuming nitric acid (IRFNA). The propulsion system provided the thrust necessary to place the GATV into a selected orbit and to accomplish major orbital changes. A minimum of five starts was available for performing these maneuvers.

Engine: 132 kg (291 lb). Chamber Pressure: 34.00 bar. Area Ratio: 45. Propellant Formulation: RFNA/UDMH. Oxidizer to Fuel Ratio: 2.57. Coefficient of Thrust vacuum: 1.829. Restarts: 13.