Hadley engine

{{Short description|Rocket engine}}

{{Infobox rocket engine|name=Hadley|oxidiser=LOX|length=|diameter=|burn_time=|thrust_to_weight=|chamber_pressure=|specific_impulse_sea_level=|specific_impulse_vacuum=|thrust(SL)={{convert|5000|lbf|kN|abbr=on}}|nozzle_ratio=|combustion_chamber=|capacity=|fuel=Kerosene|image=|type=liquid|cycle=Staged combustion|status=Initial Production|predecessor=|purpose=|date=|manufacturer=|designer=Ursa Major Technologies|country_of_origin=United States|caption=|image_size=|dry_weight=}}

The Ursa Major Technologies Hadley is a {{convert|5000|lbf|kN||adj=mid|disp=flip}} thrust Kerosene/LOX oxidizer-rich staged combustion cycle rocket engine.

Hadley is the first engine developed by Ursa Major Technologies. It started development in 2015, and prototypes were test fired in 2018.{{Cite web |date=2018-09-09 |title=Ursa Major Technologies wants outsourcing engines to be the norm |url=https://spacenews.com/ursa-major-technologies-wants-outsourcing-engines-to-be-the-norm/ |access-date=2022-03-24 |website=SpaceNews |language=en-US}} In March 2022 qualification of the engine was complete and flight-ready engines had been delivered to customers. In March 2024 Stratolaunch Systems announced completion of the first powered flight of the Talon-A test vehicle, TA-1.{{cite web | url=https://www.stratolaunch.com/news/stratolaunch-celebrates-first-powered-flight-of-ta1/ | title=Stratolaunch Celebrates First Powered Flight of TA-1 Test Vehicle }} Hadley is the engine powering Talon-A.{{cite press release | url=https://www.prnewswire.com/news-releases/ursa-major-hadley-engine-flies-for-the-first-time-302084726.html | title=Ursa Major Hadley Engine Flies for the First Time }}

Another initial customer, Phantom Space Corporation, plans to use Hadley on their Daytona small-lift rocket.{{Cite web |last=Berger |first=Eric |date=2022-03-23 |title=Ursa Major says its Hadley engine supports vertical launch and hypersonic uses |url=https://arstechnica.com/science/2022/03/ursa-major-says-its-hadley-engine-supports-vertical-launch-and-hypersonic-uses/ |access-date=2022-03-24 |website=Ars Technica |language=en-us}} ABL Space Systems initially announced they would use the Hadley engine for the upper-stage of their RS1 rocket, but have subsequently decided to use an internally-developed engine called E2.{{Cite web |date=2019-02-01 |title=ABL Space Systems increases performance and cuts price of its small launch vehicle |url=https://spacenews.com/abl-space-systems-increases-performance-and-cuts-price-of-its-small-launch-vehicle/ |access-date=2022-03-24 |website=SpaceNews |language=en-US}} In April 2023, Astra suggested the vacuum variant of the Hadley engine would power the second stage of their Rocket 4.0 launch vehicle.{{Citation |title=Launch System 2: Upper Stage Engine |url=https://www.youtube.com/watch?v=rfHEVcdGIFw |access-date=2023-04-24 |language=en}}