Activities on Development of H-IIB Launch Vehicle Propulsion System
- Paper number
IAC-07-C4.1.01
- Author
Mr. Iwao Igarashi, Mitsubishi Heavy Industries-Nagoya Aerospace Sys., Japan
- Year
2007
- Abstract
Japan’s H-IIA launch vehicle has achieved 11 successful flights. Succeeding the achievement, we are now developing H-IIB launch vehicle since 2004 to satisfy various customer needs, such as to launch heavier payloads, multi payloads, or HTV (H-IIA transfer vehicle to the ISS). The capability for GTO payload is 8.0 metric ton and the inaugural launch is planned at the beginning of 2009.
The feature of H-IIB is as follows.
- Enlargement of the 1st stage diameter (4m Dia → 5.2m Dia)
- Clustering of the 1st stage engines (LE-7A x 1 → LE-7A x 2)
- Modification of ground equipment.(Vehicle Assembling Building, etc.)
Keywords to develop H-IIB are;
- Basically based on H-IIA’s flight proven technologies.
- Shear major equipments with H-IIA, such as engines and components.
- Front loading: Early design validation through testing.
- Key technology: Clustering of the 1st stage engines.
Vast range of numerical analyses will be conducted in basic design phase to enhance reliability of the system and minimize risk of development test. Each analysis will be verified in subsystem test or stage firing test.
In this paper, some technical approaches to the 1st stage engine clustering are shown.
- Dynamic pressure or thermal environment problem due to the plume interference of two LE-7As and four SRB-As is evaluated by using numerical analysis which has been verified by the flight data of H-IIA.
- Fluid interference phenomenon between engines and tank system especially at engine start or cut-off phase is assessed, too. At designing the propellant feed system, propellant tank pressurization system, numerical analysis has been performed.
- The method and results of analysis will be verified in a stage-firing test (BFT) in 2008.
- Abstract document