The RS-25 engine test (Photo: NASA)
US Space agency NASA has throttled one of its RS-25 engines up to 113% of its rated power for the first time in a test-firing.
Development Engine 0528 (E0528) was hot fired for about four minutes in the A-1 test stand at the Stennis Space Center, Mississippi, on February 21.
Four Aerojet Rocketdyne-built RS-25 engines will be used on the Space Launch System (SLS). The SLS is NASA’s future launch system to send astronauts and cargo to explore the moon and other deep space destinations.
As reported by NASAspaceflight.com there were two primary objectives for the test at the higher throttle setting: to demonstrate engine performance and stability, and performance of the pogo.
The test duration was 260 seconds. During the firing, E0528 was throttled at 109% RPL (Rated Power Level) for 137 seconds, and at 113% RPL for 50 seconds. The engine was started with liquid oxygen (LOX) conditioned to be colder than normal. The engine uses LOX as its oxidizer and liquid hydrogen (LH2) for its fuel.
The pogo is a 3D-printed vibration dampening device, also known as the pogo accumulator assembly, manufactured at Aerojet Rocketdyne’s facility in Los Angeles, California.
The pogo accumulator assembly consists of two components: the pogo accumulator and pogo-z baffle. Both are made using a 3D printing technique called selective laser melting, which uses lasers to fuse metal powder into a pattern by adding layer upon layer of material to produce the part. On the pogo accumulator the new manufacturing technique reduced the number of welds by 78%.
The pogo accumulator assembly is the first of several of the RS-25 engine components for future SLS vehicles that are being manufactured and assembled using newer, more cost-effective processes. These include manufacturing methods such as 3D printing. The RS-25 engine was used to launch NASA’s space shuttles.
February 23, 2018