TIM FURNISS / LONDON
Booster will carry two test payloads which will demonstrate its suitability for operational and commercial work
Japan's second uprated H2A booster, a 2024 version with four additional small solid boosters (SSBs), will be launched from Tanegashima on 3 February.
The booster will carry two test payloads - the Mission Demon-stration Test Satellite 2 (MDS) and the Demonstrator of Atmospheric Re-entry System with Hyper Velocity (DASH) - to prepare the way for operational national and potential commercial missions.
The MDS is a 450kg (990lb) scale model of a communications satellite to demonstrate a suite of new technology components for future operational spacecraft. Operating with 900W of power, the three-axis stabilised spacecraft will be placed into a geostationary orbit.
It will carry commercial semiconductor devices and solar cells made using different processes and from different materials to assess their operation in a space radiation environment. MDS also features new battery, solid state data recorder, computer and space environment and radiation monitors.
The 86kg, spin-stabilised DASH will demonstrate a high velocity atmospheric Earth re-entry. It comprises a spacecraft bus with propulsion, communications and attitude control systems and a re-entry capsule which will plunge through the atmosphere at 10km/s (372 miles/min) to evaluate technologies and profiles for planetary entry probes and future transportation systems.
The 400mm (16in) diameter, 19kg DASH re-entry capsule will be recovered after a parachute landing in Mauritania.
The first H2A, a 202 model with two standard solid rocket strap-on boosters, was launched successfully on 29 August last year, to demonstrate an improved, more cost-effective satellite launcher to replace the original H2, which suffered two consecutive failures before cancellation in 1999. The H2 flew seven missions, but at $180 million per flight it was deemed too expensive to compete commercially.
Japan plans to develop five models of the new H2A offering geostationary transfer orbit (GTO) launch capability from 4,000kg to 7,500kg, comprising common units stacked together in progressively larger configurations.
Models of the H2A are due to make 11 national operational and developmental launches through to 2005. The first operational satellite, the Data Relay Test Satellite W, will be next to fly.
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 over the H2's LE5A - and has a burn time of 534s.
The H2A202 is also equipped with two SRB-A solid rocket boosters powered by polybutadiene composite propellant, with a combined thrust of 460t and a burn time of 100s. The H2A202 provides the same 4,000kg GTO performance of the H2, with 4,100kg to sun-synchronous orbit and 10,000kg to low Earth orbit.
The H2A2022 model uses two small solid boosters (SSB) to augment the initial thrust of the vehicle. Each SSB, powered by similar solid propellant, has a thrust of 26t and improves GTO performance to 4,250 kg.
The H2A2024 incorporates four SSBs, raising GTO performance to 4,500kg. The H2A212 uses the H2A202 configuration with an extra first stage strapped to the core booster, which provides 7,500kg to GTO performance. An H2A222 booster, with two strap-on core boosters, has been proposed but not funded.
Source: Flight International
