Firefly Vira
Firefly Aerospace Vira vacuum-optimized liquid rocket engine variant for the Eclipse second stage. Firefly's current vehicle specification identifies one Vira engine at 890 kN vacuum thrust and 328 seconds specific impulse using a LOX/RP-1 tap-off cycle; the engine remains in development and is based on the flight-proven Lightning architecture.
Identity
- Aliases
- Vira engineFirefly Vira vacuum engine
- Domains
- spaceflight
- Identity Level
- variant
- Kind
- liquid-rocket-engine
- Name
- Firefly Vira
- Status
- development
Details
- Description
- Firefly Aerospace Vira vacuum-optimized liquid rocket engine variant for the Eclipse second stage. Firefly's current vehicle specification identifies one Vira engine at 890 kN vacuum thrust and 328 seconds specific impulse using a LOX/RP-1 tap-off cycle; the engine remains in development and is based on the flight-proven Lightning architecture.
- Developers
- Lineage
- Note
- Firefly filings describe Vira as based on Alpha's second-stage vacuum-optimized Lightning engine; this edge records the source-backed technology boundary without treating Vira as the same identity.
- Related Propulsion System
- Relationship
- shares-core-with
- Sources
- Nested value
- Nested value
- Manufacturers
- Propellants
- RP-1liquid oxygen
- Rocket Specs
- Cycle
- tap-off
- Vacuum Specific Impulse S
- 328
- Vacuum Thrust Kn
- 890
Links
- Official Url
- https://fireflyspace.com/eclipse/
Assets & Meta
- Creation Time
- August 14, 2026 at 18:35:51 UTC
- Updated Time
- August 14, 2026 at 18:35:51 UTC
Other
- Sources
- Accessed Date
- 2026-08-14
- Note
- Identifies one Vira engine on Eclipse's second stage, with 890 kN vacuum thrust, 328 s specific impulse, LOX/RP-1 propellant, and tap-off combustion.
- Publisher
- Firefly Aerospace
- Title
- Eclipse Launch Vehicle
- Accessed Date
- 2026-08-14
- Note
- Confirms the Eclipse program's Vira engine technology boundary and ongoing development.
- Publisher
- Firefly Aerospace
- Title
- Northrop Grumman Invests $50 Million in Firefly Aerospace to Advance Medium Launch Vehicle Named Eclipse