section_path: Engines/Vira
section_name: Vira
paragraph_text: Vira
  
  Vira (formerly known as "Miranda Vacuum," "Viranda," and "Lightning 2") is a vacuum-optimized version of Miranda designed for the upper stage of Firefly's MLV vehicle. Like the Miranda, the engine will be fueled by RP-1 and LOX. It is expected to produce 890 kilonewtons (200,000 lb) of thrust and a specific impulse of 328 seconds (3.22 km/s) in vacuum. It is relightable for missions requiring multiple upper stage burns.