LE-7A

Mitsubishi LOx/LH2 rocket engine. In production. Improved model of the original LE-7 for the first stage of the H-II rocket with a two stage combustion cycle system. First flight 2001.

The LE-7A rocket engine, developed for the first stage of the H-II rocket, had a two stage combustion cycle system, and was an improved model of the original LE-7 engine. The improvements were made as a result of the severe competition in the artificial satellite business worldwide, and the resulting need to lower the cost of the H-II vehicle for the H-IIA model. The changes were targeted to increase the reliability, improve the operability, and decrease the cost for the first stage engine for the H-IIA rocket. The result was a simplified, lower cost version of LE-7 with a staged combustion turbopump that could be throttled to 72% of rated thrust.

Engine: 1,800 kg (3,900 lb). Chamber Pressure: 121.00 bar. Area Ratio: 51.9. Oxidizer to Fuel Ratio: 5.9.