Archimedes (rocket engine)

Archimedes was presented on December 2, 2021, in a webcast by Rocket Lab CEO Peter Beck as a fully reusable, gas generator engine using liquid oxygen (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 {{cvt|1|MN|lbf}} and 320 seconds of specific impulse. The same day, the Neutron page on Rocket Lab's website was updated specifying the thrust of the nine Archimedes engines used on the first stage as {{cvt|5960|kN|lbf}} at sea level and a maximum thrust of {{cvt|7530|kN|lbf}} and the upper stage's single vacuum optimized Archimedes at {{cvt|1110|kN|lbf}}. It was expected to have its first hot-fire test during May 2024. In an interview published on the CNBC website, 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 {{cvt|730|kN|lbf}} with a specific impulse of 329 seconds and would be able to throttle to 50% of maximum thrust.{{cn|date=November 2024}}

Meanwhile, the vacuum optimized version would have a maximum thrust of {{cvt|890|kN|lbf}}, a specific impulse of 367 s 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 the following quarter, hopefully starting full engine testing at Stennis before the end of 2023, and hoped to be able to launch by mid 2025.{{cn|date=November 2024}}

Archimedes is presented as a highly reusable liquid-propellant engine using methane and liquid oxygen in an oxidizer-rich staged combustion cycle. There are both sea-level and vacuum variants. The engine is mostly 3D printed,{{Cite web |date=12 April 2024 |title=With Senior Advisor to Californian Governor Gavin Newsom, Dee Dee Myers and Rocket Lab 's Peter Beck at Rocket Lab's Long Beach facility. Had a thorough discussion about more opportunities for business between New Zealand and California & how much better we are working together. |url=https://twitter.com/JudithCollinsMP/status/1778944889784512685 }} with some of the biggest 3D printers in the world. The rationale for the cycle change from the original gas generator was that they could not get the performance they needed through all the throttle points that a reusable rocket needs, without pushing the turbine temperature and other factors beyond their preset limits. By changing to the higher performing cycle but with lower performance requirements, they were able to lower temperatures and other stress factors and increase margins everywhere, making reusability more attainable.

{{Portal|Spaceflight}}

• Rocket Lab Neutron
• Rutherford (rocket engine)
• Curie (rocket engine)
• Merlin (rocket engine family)
• SpaceX Raptor

{{Reflist|30em|refs=

{{cite web |url=https://www.rocketlabusa.com/launch/neutron/ |archive-url=https://web.archive.org/web/20211202135332/https://www.rocketlabusa.com/launch/neutron/ |archive-date=2021-12-02 |title= Neutron Rocket Lab |publisher=Rocket Lab |date=2021-12-02 |access-date=2021-12-02}}

{{cite AV media | people = | date =2021-12-02 | title = Neutron Rocket - Major Development Update | type = YouTube video | url = https://www.youtube.com/watch?v=A0thW57QeDM&t=896 | access-date = 2021-12-02 | publisher = Rocket Lab}}

{{cite web |url=https://www.nasaspaceflight.com/2021/12/neutron-update-dec-2021/ |archive-url=https://web.archive.org/web/20211202185423/https://www.nasaspaceflight.com/2021/12/neutron-update-dec-2021/ |archive-date=2021-12-02 |title=Neutron switches to methane/oxygen, 1 Meganewton Archimedes engine revealed |last=Gebhardt |first=Chris |publisher=NASA SpaceFlight |date=2021-12-02 |accessdate=2021-12-02}}

{{cite web |url=https://www.cnbc.com/2021/12/02/rocket-lab-reusable-neutron-rocket-update-competing-with-spacex.html |archive-url=https://web.archive.org/web/20211202203113/https://www.cnbc.com/2021/12/02/rocket-lab-reusable-neutron-rocket-update-competing-with-spacex.html |archive-date=2021-12-02 |title= Neutron Rocket Lab |publisher=CNBC |first=Michael |last=Sheetz |date=2021-12-02 |access-date=2021-12-02}}

{{cite web |url=https://s28.q4cdn.com/737637457/files/doc_presentations/2022/09/Final_Investor-Day-Presentation-2022_Sept-21.pdf |archive-url=https://web.archive.org/web/20220922122458/https://s28.q4cdn.com/737637457/files/doc_presentations/2022/09/Final_Investor-Day-Presentation-2022_Sept-21.pdf |archive-date=2022-09-22 |title= 2022 Inverstor Day and Neutron Update |publisher=Rocket Lab |date=2022-09-21 |access-date=2022-09-22}}

{{cite AV media | people = | date=2022-09-21 | title = Rocket Lab 2022 Investor Day & Neutron Update | type = YouTube video | url = https://www.youtube.com/watch?v=Q6FW3WQu0w0?t=4710 | access-date=2022-09-22 | publisher = Rocket Lab}}

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• [https://www.rocketlabusa.com/launch/neutron/ Rocket Lab Neutron Rocket]

{{Rocket engines}}

{{Rocket Lab}}

Archimedes

Category:Rocket engines using methane propellant

Category:Rocket engines using the gas-generator cycle

Category:Space programme of New Zealand

Category:Space program of the United States