RL10B-2
The extendible-nozzle RL10 variant used by Delta IV and the current SLS Block 1 interim upper stage.
Identity
- Domains
- spaceflight
- Identity Level
- variant
- Kind
- liquid-rocket-engine
- Name
- RL10B-2
- Status
- active
Details
- Description
- The extendible-nozzle RL10 variant used by Delta IV and the current SLS Block 1 interim upper stage.
- Developers
- Family
- First Flight Date
- 2002-11-20
- Manufacturers
- Propellants
- liquid hydrogenliquid oxygen
- Rocket Specs
- Restartable
- Yes
- Vacuum Specific Impulse S
- 465
- Vacuum Thrust Kn
- 110.1
Links
Assets & Meta
- Creation Time
- July 29, 2026 at 09:03:01 UTC
- Updated Time
- August 21, 2026 at 10:32:40 UTC
- Image
- Download
Other
- Sources
- Accessed Date
- 2026-07-29
- Publisher
- NASA Technical Reports Server
- Title
- Cryogenic upper stage propulsion: RL10 and derivative engines
- 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
- Space Launch System Block 1 official vehicle reference
- Accessed Date
- 2026-07-29
- Publisher
- NASA
- Title
- SLS RL10 Engine Fact Sheet
- 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
- Delta IV Medium+ (5,4) official vehicle reference
- Accessed Date
- 2026-08-15
- Note
- ULA's inaugural Delta IV record identifies the Pratt & Whitney RL10B-2 as the cryogenic second-stage engine on the 20 November 2002 first flight.
- Publisher
- United Launch Alliance
- Title
- Critical Events of the Inaugural Launch of the Boeing Delta IV