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LE-7
Engine Model: LE-7. Designer: Mitsubishi. Propellants: Lox/LH2. Thrust(vac): 1,078.000 kN (242,344 lbf). Thrust(sl): 843.500 kN (189,626 lbf). Isp: 446 sec. Isp (sea level): 349 sec. Burn time: 346 sec. Mass Engine: 1,714 kg (3,778 lb). Diameter: 4.00 m (13.10 ft). Length: 3.40 m (11.10 ft). Chambers: 1. Chamber Pressure: 127.00 bar. Area Ratio: 52.00. Oxidizer to Fuel Ratio: 5.90. Thrust to Weight Ratio: 64.13. Country: Japan. First Flight: 1994. Last Flight: 1999. Flown: 7.00.

Staged combustion turbopump. No throttle capability.


Engine Model: LE-7A. Designer: Mitsubishi. Developed in: 1995-2001. Propellants: Lox/LH2. Thrust(vac): 1,098.000 kN (246,840 lbf). Isp: 438 sec. Isp (sea level): 338 sec. Burn time: 390 sec. Mass Engine: 1,800 kg (3,900 lb). Length: 3.67 m (12.04 ft). Chambers: 1. Chamber Pressure: 121.00 bar. Area Ratio: 51.90. Oxidizer to Fuel Ratio: 5.90. Country: Japan. Status: In production. First Flight: 2001. Last Flight: 2006. Flown: 10.

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.



LE-7 used on Rocket Stages


Bibliography:

  • Kudryavtseva, V M, ed., Zhidkostnikh Raketnikh Dvigatley, Visshaya Shkola, Moscow, 1993.


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