section_path: Engines/Reaver
section_name: Reaver
paragraph_text: Reaver
  
  Reaver is an expendable rocket engine designed for use on Firefly's Alpha rocket. It produces 184 kilonewtons (41,000 lb) of thrust and a specific impulse of 295.6 seconds (2.899 km/s). It is powered by RP-1 and liquid oxygen as its fuel and oxidizer, respectively. Reaver is fixed-throttle, meaning it runs at full power from ignition to first stage shutdown (eschewing the typical throttle-down performed by many vehicles at Max-Q to reduce aerodynamic loads) and is ignited with the pyrophoric combination TEA - TEB (also used on the SpaceX Merlin and Rocketdyne F-1). It utilizes a pintle-type injector.
  
  In 2021, The Verge reported that Astra Space had purchased up to 50 modified Reaver engines and a technology transfer to license-build their own version of Reaver in-house for their Rocket 4 vehicle. Astra refers to this engine as Chiron. It is largely the same as Reaver, but Firefly implemented a two-axis hydraulic gimbal and a modified startup sequence to meet Astra's demands, as part of Firefly's space propulsion program.