This week in 1964, the first Saturn V S-IVB, or third stage test hardware was delivered to NASA’s Marshall Space Flight Center from Long Beach, California. The S-IVB stage forward skirt would connect the top of the stage to the vehicle’s instrument unit. Developed and manufactured by Douglas Aircraft Co., the S-IVB measured about 21 1/2 feet in diameter, was about 58 feet in length and was powered by one J-2 engine capable of producing 225,000 pounds of thrust. Here, the fully assembled S-IVB for the SA-503 rocket, the Apollo 8 mission, is in Douglas’ vertical checkout building. This July, in a series of special events, NASA is marking the 50th anniversary of the Apollo Program — the historic effort that sent the first U.S. astronauts into orbit around the Moon in 1968, and landed a dozen astronauts on the lunar surface between 1969 and 1972. For more pictures, and to connect to NASA’s remarkable history, visit the Marshall History Program’s webpage. (NASA)