Archimedes

Archimedes is a liquid-fuel rocket engine burning liquid oxygen and liquid methane in an oxidizer-rich staged combustion cycle. It is designed by aerospace company Rocket Lab for its Neutron rocket. History Archimedes was presented on December 2, 2021, in a webcast by Rocket Lab CEO Peter Beck. It was presented as a fully reusable, gas generator engine using LOX and methane as propellant, a departure from the company's previous Rutherford, which is electrically pump fed. He then stated that it had a thrust of and 320 seconds of specific impulse. The same day, the Neutron page on Rocket Lab's website was updated specifying the thrust of the seven Archimedes used on the first stage as at sea level and a maximum thrust of and the upper stage's single vacuum optimized Archimedes at . It is expected to have its first hot-fire test during 2022. In an interview published on CNBC website, Mr. Beck stated that Archimedes would be manufactured in New Zealand and its very simple design had "all the things you want when you have to build an engine that can be reused over and over again.” In the September 21st, 2022 Investor Day Presentation, the engine design had changed to an oxidizer-rich staged combustion cycle. The presentation stated that the sea level version would have a maximum thrust of with an isp of 329s and would be able to throttle to a 50% of maximum thrust. Meanwhile, the vacuum optimized version, would have a maximum thrust of , an isp of 367s and the same throttling capabilities of 50% of maximum thrust. It was also implied, but not confirmed, that the engine would be built in the Virginia, USA factory. It was disclosed they would use the Stennis Space Center A-3 Test stand for development testing. They expected to start preburner testing in that or following quarter, hopefully starting full engine testing at Stennis before 2023 ends, and hoped to be able to launch in 2024.