Some of the most highly tested and efficient rocket engines in the world are firing up for their upcoming missions to deep space. They will be part of NASA’s new rocket, Space Launch System (SLS).
As SLS is evolvable, certain components of the rocket will be upgradeable to support the demands of future missions. The exploration upper stage will become more powerful with an advanced pair of boosters to be added in the future. Throughout the different configurations of SLS, the four RS-25 engines will remain the same.
SLS Block 1. Image credit: NASA/MSFC
Improving upon an already strong legacy of success, the RS-25 engines are enhanced versions of the main engines used on space shuttle flights. These engines have powered 135 shuttle missions, and will now go on to power deep space missions. The requirements for SLS are different than the space shuttle; the engines will operate at 109% power for SLS instead of 104.5%. This means that they must be certified for a higher level of thrust.
These powerful engines will power the core stage of the largest rocket in the world. With more than one million seconds of firing both in ground tests and during flight, the RS-25 engine is one of the most tested large rocket engines in the world.
RS-25. Image credit: Aerojet Rocketdyne
A test firing of the engine earlier this month supplied data on engine performance even though operations were halted partway through the test. The early shutdown of the engine was not due to any issues with the engine, only a minor issue with the test stand.
RS-25 engine firing. Image credit: NASA/SSC
The engine tests take place at NASA’s Stennis Space Center in Mississippi. Developmental tests began for the engine last year. Collecting data on the new engine controller and operating parameters that are higher than those for the space shuttle are the focus of the tests. It’s important that the new engine controller is functioning as it should be. Among factors that it controls are the mixture of propellant and thrust level.
The SLS requires that the engines be able to withstand colder engine compartment and liquid oxygen temperatures, more propellant pressure and higher exhaust nozzle temperatures. Further tests will evaluate the three controllers and the hydraulic engine shutdown.
The RS-25 engines were built by prime contractor Aerojet Rocketdyne, a founding member of the Coalition. These engines will be part of the power enabling SLS to support exploration missions in deep space. SLS will launch for the first time in 2018 on Exploration Mission-1, or EM-1.
To learn more about NASA’s new rocket, visit NASA.gov.