TIM FURNISS / LONDON
Successful launch of first of four models paves way for operational mission
After a series of mishaps, including two H2 failures, Japan's $71 million H2A launch vehicle successfully completed its maiden flight from Tanegashima on 29 August, placing a 3t spherical vehicle evaluation payload (VEP) into orbit.
"We want to let the world know Japan's rocket programme is back on track," says Shuichiro Yamanouchi, director of Japan's National Space Development Agency. "This was just the first launch. It's important we move ahead with preparations for the second and third."
A second mission will be flown in December carrying another VEP as well as a mission demonstration satellite. It will be followed by the first operational mission in February, carrying the Advanced Earth Observation Satellite and three small piggyback spacecraft.
The H2A202 is the first in a series of uprated H2A versions, produced more cheaply than the H2. It will eventually enable Japan to offer commercial launches to geostationary transfer orbit (GTO) of payloads weighing up to 7.5t.
There are four planned models of the H2A offering GTO launch capability in a payload range of 4t to 7.5t and made up of common units stacked together in progressively larger configurations.
The H2A202 comprises the basic two stage H2, with improved propulsion units. The uprated LE7A first stage engine is powered by liquid oxygen and liquid hydrogen cryogenic propellants producing a thrust of 112t and with a burn time of 390s. The uprated LE5B cryogenic engine produces a thrust of 14t - a 13% increase on the H2's LE5A - and a burn timeof 534s.
The H2A202 is also equipped with two SRB-A solid rocketboosters powered by polybutadiene composite propellant, with a combined thrust of 460t and a burn time of 100s. These replace the two SRBs used on the H2.
The H2A202 provides the same 4t GTO performance of the H2, with 4.1t to sun-synchronous orbit and 10t to low Earth orbit.
The H2A2022 model would also include two small solid boosters (SSBs) used on some H2s, to augment initial thrust. Each SSB, powered by solid propellant, has a thrust of 26t and improves GTO performance to 4.23t.
The H2A2024 incorporates four SRBs, raising GTO performance to 4.5t. The H2A212 uses the H2A202 configuration with an extra first stage strapped to the core booster. This provides 7.5t to GTO performance. An H2A222 booster with two strap-on core boosters has been proposed but not funded.
Source: Flight International
