Hadley is the first engine developed by Ursa Major Technologies. It started development in 2015, and prototypes were test fired in 2018.[1] In March 2022 qualification of the engine was complete and flight-ready engines had been delivered to customers.[2] In March 2024 Stratolaunch Systems announced completion of the first powered flight of the Talon-A test vehicle, TA-1.[3] Hadley is the engine powering Talon-A.[4]
Another initial customer, Phantom Space Corporation, plans to use Hadley on their Daytona small-lift rocket.[2]ABL Space Systems initially announced they would use the Hadley engine for the upper-stage[1] of their RS1 rocket, but have subsequently decided to use an internally-developed engine called E2.[5] In April 2023, Astra suggested the vacuum variant of the Hadley engine would power the second stage of their Rocket 4.0 launch vehicle.[6]
