
Aerojet Rocketdyne technicians inspect the new controller on the RS-25 development engine. (Credit: Aerojet Rocketdyne Inc.)
An RS-25 rocket engine with a new flight-model engine controller and flight configuration software was successfully tested for the first time at NASA's Stennis Space Center on March 23, 2017. Four RS-25 engines, manufactured by Aerojet Rocketdyne, will help propel NASA's Space Launch System (SLS) rocket, America's next-generation heavy-lift launch vehicle, and the controller unit is a key component for the rocket's safety and reliability.
The controller often is referred to as the brain of the engine, because it translates the vehicle's commands into action while monitoring the engine's health. It makes real-time adjustments by tracking critical operating conditions, such as the speed of the turbopumps, combustion pressures and temperatures, thrust, and propellant ratios. The new controller for the RS-25 engine is a significant upgrade from the controller used when the engine flew on the space shuttle, and it builds off the additional experience gained more recently with Aerojet Rocketdyne's J-2X engine test program. The new controller has 20 times the processing capability of the shuttle-era controller and offers increased reliability while providing a weight reduction of 50 pounds to each engine.
Just think about all the advances in computing technology and electronics that have occurred over the recent years, said Dan Adamski, RS-25 program director at Aerojet Rocketdyne. We've been able to increase the processing speed, add memory and greatly improve the reliability of the entire controller communication network.