A friend just retired from my group at JPL. I constructed a poster of images that celebrate his career, which included the Apollo program, the Saturn program, and about a dozen missions at JPL. I got signatures on the poster from as many of his former colleagues as I could find. We don't have that many people left in the space program that did significant work in the 1960s, when astronauts first went to the moon. But the new generation of aerospace engineers is pretty good, and progress should continue.