Why A 1950's Rocket Engine Design Flies On NASA's 21st Century Moon Rocket.

The AJ-10 Series of Engines dates to the 1950's and an example flew last year on Artemis 1, propelling Orion into a distant retrograde orbit around the moon. It's not a single engine design, but the common factor is pressure fed, hypergolic bipropellent engines designed and built by Aerojet.

The earliest examples I can find were the AJ-10-24 on Aerobee sounding rockets, generating just over 1 ton of thrust. The AJ-10-37 propelled the Vanguard rocket second stage, which was a 3.5 ton thrust engine. That was adapted to fly on Thor/Delta, Atlas and Titan. Then the Apollo Service Propulsion system used a much larger design, which was largely a complete redesign.

The shuttle Orbital maneuvering system thrusters were a smaller 2.5 ton engine running on MMH/NTO and those same engines were refurbished for flight on Orion.

This is a fine table listing the known AJ-10 variants used in orbital spaceflight.
http://www.b14643.de/Spacerockets/Spe...

Follow me on Twitter for more updates:
  / djsnm  

I have a discord server where I regularly turn up:
  / discord  

If you really like what I do you can support me directly through Patreon
  / scottmanley