The H3 launch vehicle is currently under development as Japan's next flagship launch
vehicle, replacing the H-IIA/H-IIB. The objectives of the H3 launch vehicle are to ensure
"competitiveness in the global commercial market" and "assured access to space," as well as to
maintain and strengthen the country's industrial base by obtaining orders for commercial satellite
launches. Mitsubishi Heavy Industries Ltd. (MHI) has organized the vehicle development as the
primary contractor and taken charge of the development of the engine system. The development is
currently in the middle of the detailed design phase and is progressing as planned toward the
launch of the first vehicle in 2020. This report provides the development status, especially the
development status of the engines along with their design features, which holds the key to the
success of the entire project.
