SOHEIL
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Japan's newest H-III NGLV development project
Japan’s Office of National Space Policy has announced its intentions to build a new mainline space launch rocket to replace the highly-reliable H-II rocket, with the new rocket’s development set to Begin 2014, targeting a first launch around 2020. The primary goal of development is to drastically reduce the cost of rocket launches.
The Japan Aerospace Exploration Agency and Mitsubishi Heavy Industries Ltd. are drawing up plans to develop what they are tentatively calling the H-III rocket.
TOKYO, 2014, January -- The Japanese government has officially approved initial funding for a $1.9 billion effort to develop the H-III rocket, the designated replacement for the country’s current H-IIA workhorse launcher.
The H-III rocket could be configured with zero, two, four or six strap-on solid rocket boosters to lift heavier payloads into orbit, according to JAXA's current design concepts.
The basic configuration with no solid-fueled boosters could put up to 3 metric tons into a sun-synchronous orbit, a type of orbit often used by Earth imaging satellites.
The launcher's most powerful version, with six boosters, could put a 6.5 metric ton payload into geostationary transfer orbit, the drop-off point for communications satellites heading for operating positions 22,300 miles over the equator.
The H-III will stand about 60 meters tall and have a core stage powered by a new liquid-hydrogen/liquid oxygen main engine dubbed LE-9 and anywhere from two to six solid-fueled strap-on boosters. The solid-fueled boosters will be based closely on the M-34 second stage of Japan’s new Epsilon small rocket.
A new hydrogen-fueled LE-9 engine is in development for the first stage. Two of the engines, each generating about 300,000 pounds of thrust.
The LE-9 engine features an open expander cycle, in which hydrogen from the engine turbopump is diverted to the main combustion chamber's cooling channels and then used to drive the turbines before being injected into the combustion flow at the nozzle extension, according to a technical document produced by JAXA engineers.
Engineers say the open expander cycle, only used on upper stage engines up to now, allows the rocket engine to have a simpler design, reduces pressures and temperatures inside the engine, decreases heat on the turbines of the turbopump, and makes the engine more robust to failures.