In this image, engineers test the RL-10 engine in NASA Lewis (now
Glenn) Research Center's Propulsion Systems Laboratory. Developed by
Pratt & Whitney, the engine was designed to power the Centaur
second-stage rocket. Centaur was responsible for sending the Surveyor
spacecraft on
its mission to land on the moon and to explore the surface in the early
stages of the Apollo Program. Image Credit: NASA