(Image courtesy of NASA)
Our return to the Moon will get off the ground thanks to engines from a local company.
Those engines are from Aerojet Rocketdyne, which has facilities in Redmond. The RS-25s are formerly known as Space Shuttle main engines (the three on the Shuttle’s tail), only there are four of them at the base of Space Launch System or SLS core stage. Joe Cassady, Aerojet Rocketdyne’s Executive Director of Space, says the RS-25s on Artemis One are all Shuttle veterans. “It’s something like 20 flights they have under their belts already,” Cassady says, “One of the engines actually was on the flight that returned John Glenn to flight, after his many, many years since his orbital flight, when he got to fly on the Shuttle.”
Cassady says all four of these engines also have a piece of the engines from the first Shuttle flight in 1981, and the first four Artemis flights will launch with former Shuttle engines. The core stage is not recoverable, so these will be the final flights for those NASA workhorses, but Cassady says they can build new engines less expensively using some new tech: a 3D printer to make new parts.
During launch, the solid rocket boosters provide more than 6-million pounds of thrust, but they’re only with the SLS for 2 minutes. Once they’re jettisoned, it’s those RS-25s, with 500,000 pounds of thrust each, that carry the rocket all the way to orbit.
Cassady says Monday’s launch was scrubbed when an Engine 3 sensor gave them a higher temperature reading in the cooling system, but he says secondary data showed they were getting cold enough. Cassady says, “All the engines are showing about the same secondary data. The one thing that’s standing out as different is that sensor on Engine 3, and it’s not really even on the engine […]It’s up at the base of the core stage.” So Cassady says the only thing he’s worried about for the second attempt is the weather in Florida.
In addition to the SLS engines and maneuvering thrusters on the Orion capsule, it’ll be an Aerojet RL-10 engine making the “trans-lunar injection burn” that’ll send us to the Moon.
You can see Ryan Harris’ complete interview with Joe Cassady, Aerojet Rocketdyne’s Executive Director of Space, in the video below: