The H-3 is a rocket series under development by JAXA and industrial partners. It is planned to replace the current H-2A at a lower cost.
The vehicle has a principal diameter of 5.2 m and stands approximately 63 m high.
The LOX/LH2 fueled first stage is powered by either two or three LE-9 engines, which feature 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.
For launch, the first stage can be augmented by 2 or 4 solid rocket boosters, which are improved versions of the SRB-A.
The second stage is also LOX/LH2 fueled and based on an improved LE-5B engine.
H-3 is planned to be operational by the early 2020s.
|Version||Strap-On||Stage 1||Stage 2|
|H-3-30S / H-3-30L||-||3 × LE-9||LE-5B-3|
|H-3-22S / H-3-22L||2 × SRB-A3||2 × LE-9||LE-5B-3|
|H-3-32S / H-3-32L||2 × SRB-A3||3 × LE-9||LE-5B-3|
|H-3-24S / H-3-24L||4 × SRB-A3||2 × LE-9||LE-5B-3|
No: TNr: Serial: Type: Fair Date: LS Payload
none Planned: 1 1 TF1 H-3 x xx.xx.2020 Ta YLP-2 TBD x x x H-3 x xx.xx.2022 Ta YLP-2 Inmarsat TBD Launch sites: Ta = Tanegashima Space Center, Tanegashima, Japan