Aerojet AJ10-137 Service Propulsion System
Historical Aerojet-General AJ10-137 pressure-fed hypergolic service-propulsion system used as the Apollo command and service module main engine. NASA identifies the Aerojet-General Space Propulsion Division as designer, builder, and tester; the gimbalable engine generated 20,500 lbf (about 91.2 kN) with a 314.5 s specific impulse and used Aerozine 50 with nitrogen tetroxide. Block I units supported early uncrewed Apollo tests, while Block II units flew on crewed Apollo, Skylab, and Apollo-Soyuz missions.
Identity
- Domains
- spaceflight
- Identity Level
- integrated-system
- Kind
- integrated-propulsion-system
- Name
- Aerojet AJ10-137 Service Propulsion System
- Status
- historical
Details
- Description
- Historical Aerojet-General AJ10-137 pressure-fed hypergolic service-propulsion system used as the Apollo command and service module main engine. NASA identifies the Aerojet-General Space Propulsion Division as designer, builder, and tester; the gimbalable engine generated 20,500 lbf (about 91.2 kN) with a 314.5 s specific impulse and used Aerozine 50 with nitrogen tetroxide. Block I units supported early uncrewed Apollo tests, while Block II units flew on crewed Apollo, Skylab, and Apollo-Soyuz missions.
- Family
- First Run Date
- 1963-06-26
- Propellants
- Aerozine 50nitrogen tetroxide
- Retirement Date
- 1975
- Rocket Specs
- Cycle
- pressure-fed
- Vacuum Specific Impulse S
- 314.5
- Vacuum Thrust Kn
- 91.2
Links
Assets & Meta
- Creation Time
- July 29, 2026 at 08:10:59 UTC
- Updated Time
- August 22, 2026 at 06:52:20 UTC
Other
- Sources
- Accessed Date
- 2026-07-29
- Note
- NASA identifies Aerojet-General's Space Propulsion Division as the AJ10-137 SPS designer/builder/tester, reports 20,500 pounds of thrust and a gimbalable nozzle, and distinguishes Block I uncrewed from Block II crewed Apollo configurations.
- Publisher
- NASA
- Title
- 60 Years Ago: First Test Firing of the Apollo Service Propulsion System
- Accessed Date
- 2026-07-29
- Note
- Supports the Apollo command-and-service-module installation boundary for the integrated AJ10-137 service propulsion system.
- Publisher
- Official vehicle or program source
- Title
- Apollo Command and Service Module official vehicle reference
- Accessed Date
- 2026-08-21
- Note
- NASA technical documentation describes the AJ10-137 configuration as pressure-fed and records 314.5 s specific impulse; the value is added to the integrated service-propulsion system's technical fields.
- Publisher
- NASA Technical Reports Server
- Title
- Aerojet - AJ10-137 Apollo Service Module Engine