STENNIS SPACE CENTER, Miss. - Workers at Stennis Space Center are engaged in a maintenance project to protect the flame deflector on the Fred Haise Test Stand, where RS-25 engines for NASA’s Space Launch System (SLS) rocket are tested. During testing on the stand, an RS-25 engine’s combustion chamber reaches 6,000 degrees Fahrenheit. Its exhaust plume hits the test stand’s J-shaped flame deflector at temperatures around 5,000 degrees Fahrenheit. The exhaust is cooled by high-pressure water sprayed into the test stand flame deflector through thousands of 5/32-inch holes. Without the 170,000 gallons of water pumped every minute from the nearby High Pressure Industrial Water Facility, the carbon-steel flame deflector would melt under the superhot exhaust plume. The exhaust hits some parts of the flame deflector more directly and with more heat than others. To offset the effect, the pattern of holes must be precise and uniquely tailored for a particular test project. Crews are now in the process of performing critical modifications on the Fred Haise Test Stand flame deflector. A key part of the work is drilling a new, highly specialized hole pattern to improve water cooling and protect the infrastructure. The hole pattern will be uniquely tailored for the RS-25 testing program. In addition to the spray pattern effort, weld crews also are completing work on the flame deflector manifold structure. Having tested rocket engines and stages dating back to the Apollo missions, the Fred Haise Test Stand has a proven history of bearing the same temperatures and forces produced by a rocket engine during launch. However, testing RS-25 engines for SLS use has presented a new set of challenges. The engines sit at a lower point in the test stand (closer to the flame deflector) and operate at higher power levels than engines from some previous test programs. (Source:
NASA/SSC, 05/04/22)
