LE-5
LE-5 is the original liquid-hydrogen/liquid-oxygen upper-stage engine developed in Japan for H-I. Its gas generator supplies turbine-driving gas, unlike the later expander-bleed LE-5A and LE-5B designs. JAXA lists 103 kN vacuum thrust, 450 s vacuum specific impulse, 2.7 m overall length and 260 kg mass for this model.
Identity
- Domains
- spaceflight
- Identity Level
- model
- Kind
- liquid-rocket-engine
- Name
- LE-5
- Status
- retired
Details
- Description
- LE-5 is the original liquid-hydrogen/liquid-oxygen upper-stage engine developed in Japan for H-I. Its gas generator supplies turbine-driving gas, unlike the later expander-bleed LE-5A and LE-5B designs. JAXA lists 103 kN vacuum thrust, 450 s vacuum specific impulse, 2.7 m overall length and 260 kg mass for this model.
- Dry Mass
- …
- Family
- Length
- …
- Propellants
- liquid hydrogenliquid oxygen
- Rocket Specs
- Cycle
- gas-generator
- Restartable
- Yes
- Vacuum Specific Impulse
- …
- Vacuum Thrust
- …
Links
Assets & Meta
- Creation Time
- July 29, 2026 at 08:48:30 UTC
- Updated Time
- October 29, 2026 at 15:30:48 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-I 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-5 table: 103 kN vacuum thrust, 450 s vacuum Isp, 2.7 m overall length, 260 kg mass; H-I application.
- Publisher
- Japan Aerospace Exploration Agency
- Title
- LE-5B and LE-5-series engine comparison