LE-5A
LE-5A is the liquid-hydrogen/liquid-oxygen engine developed for H-II’s second stage. It introduced the expander-bleed cycle to the LE-5 line, using heated hydrogen from nozzle cooling to drive the pumps, and supported multiple ignitions in orbit. JAXA’s model comparison lists 122 kN vacuum thrust, 453 s vacuum specific impulse, 2.7 m overall length and 250 kg mass.
Identity
- Domains
- spaceflight
- Identity Level
- variant
- Kind
- liquid-rocket-engine
- Name
- LE-5A
- Status
- retired
Details
- Description
- LE-5A is the liquid-hydrogen/liquid-oxygen engine developed for H-II’s second stage. It introduced the expander-bleed cycle to the LE-5 line, using heated hydrogen from nozzle cooling to drive the pumps, and supported multiple ignitions in orbit. JAXA’s model comparison lists 122 kN vacuum thrust, 453 s vacuum specific impulse, 2.7 m overall length and 250 kg mass.
- Dry Mass
- …
- Family
- Length
- …
- Lineage
- Note
- JAXA identifies LE-5A as the higher-performance successor developed from LE-5.
- Related Propulsion System
- Relationship
- direct-derivative-of
- Sources
- Accessed Date
- 2026-07-29
- Publisher
- Japan Aerospace Exploration Agency
- Title
- H-II Launch Vehicle
- Accessed Date
- 2026-07-29
- Publisher
- Japan Aerospace Exploration Agency
- Title
- LE-5B
- Propellants
- liquid hydrogenliquid oxygen
- Rocket Specs
- Cycle
- expander-bleed
- Restartable
- Yes
- Vacuum Specific Impulse
- …
- Vacuum Thrust
- …
Links
- Official Url
- https://global.jaxa.jp/projects/rockets/h2/
Assets & Meta
- Creation Time
- July 29, 2026 at 08:48:36 UTC
- Updated Time
- October 29, 2026 at 15:30:51 UTC
Other
- Sources
- Accessed Date
- 2026-07-29
- Note
- Supports the legacy vehicle installation and the narrow canonical identity used for migration.
- Publisher
- Official vehicle or program source
- Title
- H-II Launch Vehicle official vehicle reference
- Accessed Date
- 2026-07-29
- Publisher
- Japan Aerospace Exploration Agency
- Title
- LE-5B
- Accessed Date
- 2026-10-29
- Note
- LE-5A table: 122 kN vacuum thrust, 453 s vacuum Isp, 2.7 m length, 250 kg mass; H-II application and nozzle-expander-bleed cycle.
- Publisher
- Japan Aerospace Exploration Agency
- Title
- LE-5B and LE-5-series engine comparison