JAXA decided finally to launch Michibiki-3 navigational satellite after one week of delay caused by problems with H-IIA rocket.

It was 35th mission of H-IIA rocket. Primary objective was to deliver third from fourth JAXA navigational satellites. Michibiki-3 will support GPS system which is used in Japan, but suffers for some problems due the mountains and skyscrapers. These are preventing receivers on the ground from finding signal which is send from satellites flying low over horizon. That is why JAXA decided to create The Quasi-Zenith Satellite System (QZSS). Constellation of Michibiki satellites supports GPS only over Japan; in future JAXA considers extending number of satellites from four to seven.

Fifth mission of H-IIA was delayed for a week. Originally scheduled for August 11th, due the poor weather conditions was moved to August 12th. Unfortunately, in the last phase of countdown, technicians spotted leaking helium valve installed in pressurizing system and rocket returned to hangar for repair and inspection.

Third attempt was planned to be performed again from first launch pad at Yoshinobu Launch Complex at Tanegashima Space Center. Rocket was launched punctually at 05:29 UTC. All four boosters fueled with HTPB started to provide 2260 kN of thrust supporting first stage powered by 1 LE-7A engine (with 1098 kN of thrust). Rocket performed course correction to south-east and released boosters at T+2′. At T+3’45” wide for 5.1 m payload fairing was jettisoned. First stage was continuing flight until T+6’30” when it was cut off and jettisoned. Second stage started its LE-5B engine providing 137 kN of thrust for following 4 minutes 31 seconds. After reaching parking orbit, second stage was cut off. Second burn was performed to raise orbit after another 12 minutes 16 seconds and lasted for 250 seconds. After second burn Michibiki-3 was deployed at T+28’40”.

Rocket manufactured by Mitsubishi Heavy Industries, Ltd. is 53 m long with total mass of  445 t. In heaviest configuration (204) configuration rocket can be equipped with various payload fairings from 3.7 m payload fairing to even exceeding 5 m (with payload to GTO at 6 t)  and four Solid Rocket Boosters in A variant. Boosters are fueled with HTPB and are providing 2260 kN of thrust each. Rocket has two stages, first is powered by LE-7A engine burning LOX/LH-2 and providing 1098 kN of thrust. Second stage is powered by single LE-5B engine also fueled with LOX/LH2 with thrust of 137 kN.