RS-68
The RS-68 is a single-chamber LOX/LH2 gas-generator engine developed for Delta IV Common Booster Cores. Its original production form generated more than 650,000 lbf of sea-level thrust and powered the Delta IV launch family; this canonical row remains retired and does not assert the distinct RS-68A upgrade.
Identity
- Domains
- spaceflight
- Identity Level
- model
- Kind
- liquid-rocket-engine
- Name
- RS-68
- Status
- retired
Details
- Description
- The RS-68 is a single-chamber LOX/LH2 gas-generator engine developed for Delta IV Common Booster Cores. Its original production form generated more than 650,000 lbf of sea-level thrust and powered the Delta IV launch family; this canonical row remains retired and does not assert the distinct RS-68A upgrade.
- Developers
- Dry Mass Kg
- 6803.89
- Family
- First Flight Date
- 2002-11-20
- Length M
- 5.2832
- Manufacturers
- Propellants
- liquid hydrogenliquid oxygen
- Rocket Specs
- Chamber Count
- 1
- Cycle
- gas generator
- Sea Level Specific Impulse S
- 357
- Sea Level Thrust Kn
- 2,949
- Vacuum Specific Impulse S
- 409
- Vacuum Thrust Kn
- 3,372
Links
Assets & Meta
- Creation Time
- July 29, 2026 at 09:31:28 UTC
- Updated Time
- August 22, 2026 at 01:25:37 UTC
- Image
- Download
Other
- Sources
- Accessed Date
- 2026-07-29
- Publisher
- United Launch Alliance
- Title
- Final Delta IV Heavy launch
- Accessed Date
- 2026-07-29
- Note
- NASA technical material documents the original RS-68 gas-generator engine performance and the Delta IV-era engine design.
- Publisher
- NASA Technical Reports Server
- Title
- Liquid Rocket Propulsion: RS-68 and Linear Aerospike
- 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 official vehicle reference
- Accessed Date
- 2026-08-14
- Note
- NASA documents the original RS-68 as generating more than 650,000 pounds of sea-level thrust, its first flight in November 2002, 341 hot-fire tests, and 77 delivered flight-certified production engines for Delta IV.
- Publisher
- NASA
- Title
- NASA Stennis, Aerojet Rocketdyne Closes Historic Commercial Test Partnership
- Accessed Date
- 2026-08-15
- Note
- ULA and Boeing record the inaugural Delta IV/RS-68 flight on 20 November 2002.
- Publisher
- United Launch Alliance
- Title
- Critical Events of the Inaugural Launch of the Boeing Delta IV
- Accessed Date
- 2026-08-21
- Note
- NASA technical data lists the RS-68 at 15,000 lbm weight and 208 in length, alongside its 758,000 lbf vacuum and 663,000 lbf sea-level thrust ratings.
- Publisher
- NASA Technical Reports Server
- Title
- Shuttle Derived In-Line Heavy Lift Vehicle