NASA Morpheus HD4-A-LT
HD4-A-LT was the large-throat HD4-A configuration used for Morpheus 1.5B Bravo flight testing in 2013 and 2014. NASA describes reuse of the original HD4-A injector with a larger-throat chamber, increasing maximum thrust first to 5,000 lbf and then 5,400 lbf, approximately 24.02 kN. The engine supported deep throttling for takeoff, translation and landing.
Identity
- Aliases
- HD4-A-LTMorpheus large-throat HD4-A
- Domains
- spaceflight
- Identity Level
- variant
- Kind
- liquid-rocket-engine
- Name
- NASA Morpheus HD4-A-LT
- Status
- historical
Details
- Description
- HD4-A-LT was the large-throat HD4-A configuration used for Morpheus 1.5B Bravo flight testing in 2013 and 2014. NASA describes reuse of the original HD4-A injector with a larger-throat chamber, increasing maximum thrust first to 5,000 lbf and then 5,400 lbf, approximately 24.02 kN. The engine supported deep throttling for takeoff, translation and landing.
- Developers
- Family
- Lineage
- Note
- The HD4-A injector recovered from Alpha was fitted to a larger-throat chamber for the HD4-A-LT configuration.
- Related Propulsion System
- Relationship
- direct-derivative-of
- Sources
- Accessed Date
- 2026-10-29
- Note
- Engine configuration history and Table 1 distinguish HD4-A, HD4-A-LT, HD4-B-LT and ground-tested HD5.
- Publisher
- NASA Technical Reports Server
- Title
- Combustion Stability Characteristics of the Project Morpheus Liquid Oxygen / Liquid Methane Main Engine
- Manufacturers
- Propellants
- liquid oxygenliquid methane
- Rocket Specs
- Sea Level Thrust
- …
Links
Assets & Meta
- Creation Time
- October 29, 2026 at 15:36:00 UTC
- Updated Time
- October 29, 2026 at 15:36:00 UTC
Other
- Sources
- Accessed Date
- 2026-10-29
- Note
- Engine configuration history and Table 1 distinguish HD4-A, HD4-A-LT, HD4-B-LT and ground-tested HD5.
- Publisher
- NASA Technical Reports Server
- Title
- Combustion Stability Characteristics of the Project Morpheus Liquid Oxygen / Liquid Methane Main Engine