The J-2 engine for Saturn V S-IVB (third) stage blasted from the test stand at Douglas Aircraft Co., Sacramento Test Operation (SACTO) facility in California. This third stage was used on the unmarned Saturn V flight of Apollo 6 in April 1968.

This is a view of the Saturn V S-IVB (third) stage for the AS-209 (Apollo-Soyuz test project backup vehicle) on a transporter in the right foreground, and the S-IVB stage for AS-504 (Apollo 9 mission) being installed in the Beta Test Stand 1 at the SACTO facility in California. After the S-II (second) stage dropped away, the S-IVB (third) stage ignited and burned for about two minutes to place itself and the Apollo spacecraft into the desired Earth orbit. At the proper time during this Earth parking orbit, the S-IVB stage was re-ignited to speed the Apollo spacecraft to escape velocity and inject it and the astronauts into a moon trajectory. Developed and manufactured by the Douglas Aircraft Company in California, the S-IVB stage measures about 21.5 feet in diameter, about 58 feet in length, and is powered by a single 200,000-pound-thrust J-2 engine with a re-start capability. The S-IVB stage was also used on the second stage of the Saturn IB launch vehicle.

The Saturn IB S-IVB (second) stages in storage at the Douglas Aircraft Company's Sacramento Test Operations Facility (SACTO) in Sacramento, California. Designed and developed by the Marshall Space Flight Center and the Douglas Aircraft Company, the S-IVB stage was powered by a single J-2 engine, which produced 200,000 pounds of thrust, later uprated to 230,000 pounds for the Saturn V launch vehicle.

This image depicts the Saturn V S-IVB (third) stage for the Apollo 10 mission being removed from the Beta Test Stand 1 after its acceptance test at the Douglas Aircraft Company's Sacramento Test Operations (SACTO) facility. After the S-II (second) stage dropped away, the S-IVB (third) stage was ignited and burned for about two minutes to place itself and the Apollo spacecraft into the desired Earth orbit. At the proper time during this Earth parking orbit, the S-IVB stage was re-ignited to speed the Apollo spacecraft to escape velocity injecting it and the astronauts into a moon trajectory. Developed and manufactured by the Douglas Aircraft Company in California, the S-IVB stage measures about 21.5 feet in diameter, about 58 feet in length, and powered by a single 200,000-pound-thrust J-2 engine with a re-start capability. The S-IVB stage was also used on the second stage of the Saturn IB launch vehicle.