14 Dec 2021-------------------S21-047

An integrated team representing Aerojet Rocketdyne, support contractor Syncom Space Services (S3), and NASA’s Stennis Space Center recently experienced a different kind of R&R. On Oct. 13, the team members successfully performed an uncommon remove-and-replace (R&R) procedure on an RS-25 engine’s nozzle while the engine was installed on the Fred Haise Test Stand.

In fact, the event marked the first nozzle removal and replacement performed on an installed RS-25 engine since the space shuttle main engine testing era at Stennis, the nation’s largest propulsion test site located near Bay St. Louis, Mississippi. Space shuttle testing at Stennis ran from May 19, 1975, to July 29, 2009. The last flight of the Space Shuttle Program, STS-135, occurred July 8-21, 2011.

The R&R procedure involves completely removing the nozzle – the bell-shaped component bolted to the powerhead that directs and accelerates 6,000-degree exhaust to generate powerful thrust – and reattaching another nozzle, while the turbopumps, combustion chamber, fuel ducts, and other parts remain secured in place.

[Image]

(A) Technicians on the Fred Haise Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Miss., prepare to use an vertical engine installer (VEI) to support, detach, and lower the nozzle from RS-25 development engine No. 0528 during a nozzle remove-and-replace (R&R) Oct. 13.

(B) Technicians on the Fred Haise Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Miss., ensure all is in place during an RS-25 rocket engine nozzle remove-and-replace procedure Oct. 13.

(C) Technicians on the engine deck of the Fred Haise Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Miss., examine a detached nozzle from RS-25 development engine No. 0528 during a nozzle remove-and-replace (R&R) procedure on Oct. 13. The thrust frame adapter, a cross-shaped metal beam structure to which the engine is securely bolted during hot fire testing, is seen at the top of the image.