Aerojet AJ10-104
Historical Aerojet-General AJ10-104 restartable, pressure-fed hypergolic engine for the Able-Star upper stage. The declassified vehicle data specifies 7,900 lbf (35.14 kN) vacuum thrust, 277 s vacuum specific impulse, and a 296 s burn time; the system provided automatic start, restart, shutdown, and coast-period attitude-control functions with a gimballed thrust chamber, using unsymmetrical dimethylhydrazine and inhibited red fuming nitric acid.
Identity
- Domains
- spaceflight
- Identity Level
- variant
- Kind
- liquid-rocket-engine
- Name
- Aerojet AJ10-104
- Status
- historical
Details
- Description
- Historical Aerojet-General AJ10-104 restartable, pressure-fed hypergolic engine for the Able-Star upper stage. The declassified vehicle data specifies 7,900 lbf (35.14 kN) vacuum thrust, 277 s vacuum specific impulse, and a 296 s burn time; the system provided automatic start, restart, shutdown, and coast-period attitude-control functions with a gimballed thrust chamber, using unsymmetrical dimethylhydrazine and inhibited red fuming nitric acid.
- Family
- Propellants
- UDMHinhibited red fuming nitric acid
- Rocket Specs
- Burn Time S
- 296
- Cycle
- pressure-fed
- Restartable
- Yes
- Vacuum Specific Impulse S
- 277
- Vacuum Thrust Kn
- 35.14
Links
Assets & Meta
- Creation Time
- July 29, 2026 at 08:10:56 UTC
- Updated Time
- August 22, 2026 at 06:48:24 UTC
Other
- Sources
- Accessed Date
- 2026-08-14
- Note
- The declassified vehicle description identifies the Able-Star AJ10-104 as an advanced Aerojet-General restartable system with automatic start/restart/shutdown, high-pressure-helium propellant feed, gimballed thrust chamber, UDMH fuel, and inhibited red fuming nitric acid oxidizer.
- Publisher
- National Reconnaissance Office
- Title
- Able-Star Vehicle AJ10-104 propulsion description
- Accessed Date
- 2026-07-29
- Note
- Supports the historical Thor-Ablestar launch-vehicle application for the AJ10-104 variant.
- Publisher
- NASA Technical Reports Server
- Title
- Thor-Ablestar launch vehicle flight evaluation report
- Accessed Date
- 2026-08-21
- Note
- The declassified NRO vehicle sheet identifies the single AJ10-104 Able-Star upper-stage engine at 7,900 lbf vacuum thrust, 277 s vacuum specific impulse, and 296 s burn time; these are normalized to 35.14 kN, 277 s, and 296 s in the technical fields.
- Publisher
- National Reconnaissance Office
- Title
- Thor-Able-Star vehicle performance data