RS-68B
RS-68B was NASA's planned upgrade of the Delta IV RS-68 gas-generator engine for the Ares V core stage. NASA's Ares V design documentation gives the proposed variant 797,000 lbf (3,545.2 kN) vacuum thrust and 414.2 s vacuum specific impulse; this is planned design performance, not a flown production rating, and no flight installation is asserted.
Identity
- Domains
- spaceflight
- Identity Level
- variant
- Kind
- liquid-rocket-engine
- Name
- RS-68B
- Status
- development
Details
- Description
- RS-68B was NASA's planned upgrade of the Delta IV RS-68 gas-generator engine for the Ares V core stage. NASA's Ares V design documentation gives the proposed variant 797,000 lbf (3,545.2 kN) vacuum thrust and 414.2 s vacuum specific impulse; this is planned design performance, not a flown production rating, and no flight installation is asserted.
- Family
- Propellants
- liquid hydrogenliquid oxygen
- Rocket Specs
- Cycle
- gas-generator
- Vacuum Specific Impulse
- …
- Vacuum Thrust
- …
Links
- Official Url
- https://ntrs.nasa.gov/citations/20090014109
Assets & Meta
- Creation Time
- August 13, 2026 at 21:03:12 UTC
- Updated Time
- August 22, 2026 at 07:07:16 UTC
Other
- Sources
- Accessed Date
- 2026-08-13
- Note
- NASA describes RS-68B as an upgrade to the RS-68 developed for the Delta IV vehicle, intended for the planned Ares V core stage; this identity intentionally records no current vehicle installation.
- Publisher
- NASA Technical Reports Server
- Title
- Ares V and RS-68B
- Accessed Date
- 2026-08-15
- Note
- NASA identifies the baseline RS-68 as a single-chamber LOX/LH2 gas-generator engine; RS-68B is recorded here as its planned upgrade without asserting a separate flight rating.
- Publisher
- NASA
- Title
- Basics of Space Flight — Propulsion
- Accessed Date
- 2026-08-22
- Note
- NASA's Ares V design trade-space records RS-68B performance of 797,000 lbf vacuum thrust and 414.2 s specific impulse; the normalized thrust is stored in rocketSpecs and the values remain design targets for the unflown variant.
- Publisher
- NASA Technical Reports Server
- Title
- Ares V and RS-68B