When it comes to rocket engines, the RS-25 is one of the most popular and popular. It’s the same rocket engine that will be used on NASA’s lunar missions, but the Artemis missions certainly aren’t the first time that the RS-25 engines have been used. The RS-25 engine has been the primary engine of the Space Shuttle and has a proven track record of 135 missions over a period of 30 years.
When the space shuttle program was retired in 2011, 16 RS-25 engines did it NASA is using To help build the International Space Station and deploy the Hubble Space Telescope, among other missions, it has been put into storage. When NASA began researching missile engines to power the Space Launch System (SLS), the RS-25 engines were an opportunity for NASA to save money on developing a new engine. NASA chose the RS-25 engines because of their ability to leverage technology capabilities and expertise from the space shuttle program.
Described as one of the most reliable, efficient and high-performance engines ever built, the RS-25 is ahead of its era in design, engineering and performance. Among the challenges was getting the RS-25 engine to work with the new SLS. Engineers had to make design improvements to make the venerable engine ready to fly in the most demanding SLS environment.
NASA, contractor and Aerojet Rocketdyne began adapting the engines, with the first parts redesigned to become obsolete flight controllers. Flight control modules are an important component that actively controls engine operation and the management of command protocols and data between the engine and the spacecraft. A computer capable of handling modern SLS algorithms is required. With the SLS design, four engines are located at the base of the base stage of the missile next to a pair of solid rocket boosters.
This means that the nozzles of the RS-25 engine will undergo a very basic heating, especially during the first two minutes of flight. Nozzles have been improved with the addition of insulation. Another improvement has to do with where the liquid oxygen tank sits in relation to the four RS-25 motors on the SLS. The location of this tank produces high pressure at the RS-25 inlets. Nozzles had to be adopted to withstand this pressure and were able to do so with minimal upgrades. All previous 16 major engines of the space shuttle completed the April 2019 acceptance test.