YF-77
YF-77 is China's cryogenic liquid-hydrogen/liquid-oxygen expander-cycle booster engine, used as a pair on the Long March 5 core first stage and its Long March 5B derivative. CNSA identifies the engine's approximately 50-ton ground-thrust class; this packet leaves vacuum performance and actor attribution unset rather than infer them from secondary tables.
Identity
- Aliases
- YF-77 hydrogen-oxygen engine
- Domains
- spaceflight
- Identity Level
- model
- Kind
- liquid-rocket-engine
- Name
- YF-77
- Status
- active
Details
- Description
- YF-77 is China's cryogenic liquid-hydrogen/liquid-oxygen expander-cycle booster engine, used as a pair on the Long March 5 core first stage and its Long March 5B derivative. CNSA identifies the engine's approximately 50-ton ground-thrust class; this packet leaves vacuum performance and actor attribution unset rather than infer them from secondary tables.
- Propellants
- liquid hydrogenliquid oxygen
- Rocket Specs
- Cycle
- expander
- Sea Level Thrust Kn
- 490.3
Links
Assets & Meta
- Creation Time
- August 1, 2026 at 15:00:30 UTC
- Updated Time
- August 15, 2026 at 05:23:04 UTC
Other
- Sources
- Accessed Date
- 2026-08-14
- Note
- CNSA identifies two YF-77 hydrogen-oxygen engines on the Long March 5 core first stage and gives the approximately 50-ton ground-thrust class.
- Publisher
- China National Space Administration
- Title
- Long March 5: numbers behind the rocket
- Accessed Date
- 2026-08-14
- Note
- CNSA identifies YF-77 as a newly developed hydrogen-oxygen engine and places it within China's expansion-cycle cryogenic-engine capability.
- Publisher
- China National Space Administration
- Title
- New features of the Long March 5 carrier rocket
- Accessed Date
- 2026-08-14
- Note
- Government report independently identifies two YF-77 hydrogen-oxygen engines on the 5 m Long March core stage.
- Published Date
- 2024-02-24
- Publisher
- State Council Information Office of the People's Republic of China
- Title
- China launches new communication technology experiment satellite