Our SpaceFlight Heritage: 50 years since the first full Saturn V test fire
Fifty years ago, on April 16, 1965, the full power of the Saturn V was felt for the first time in a test stand firing of the cluster of five F-1 first stage (S-IC) engines at NASA’s Marshall Spaceflight Center located in Huntsville, Alabama. The five F-1 engines burned for 6.5 seconds and produced 7.5 million pounds-force (33.4 MN) of thrust. This test firing occurred two months ahead of schedule and created the loudest noise ever heard in Alabama. The mighty roar of the Saturn V’s first stage firing was heard tens of miles away.
“I give thanks and praise to the greatest test team in the world in meeting this great milestone,” said test director Harry Johnstone upon completion of the firing. “Dr. Von Braun sent me a personal letter of appreciation, recognizing that it took a great team effort and congratulating the entire team. I still treasure this personal letter today. I had a dream team behind me and there was no way that we would not succeed. My team gave their heart and soul to the program, working long, stressful and sometimes dangerous hours. I might add here that in motivating my engineers and technicians, we would stack hands on a table one on top of another drawing the conclusion that that we were all one together with the single purpose to meet our goal. Our saying was, ‘this job ain’t no hill for a stepper!’ There was an air of confidence about our whole team.”
This test was a critical milestone on the way to achieving President Kennedy’s goal of landing an American on the Moon and returning him safely by the end of the decade. The Saturn V was the brainchild of Dr. Wernher von Braun and would be the vehicle that America would literally ride to the stars. Without the Saturn V, the NASA moon landings were impossible. The Soviets’ equivalent of the Saturn V was the N1, with an unwieldy cluster of 30 engines in the first stage. All four N1 test flights were failures (1969-1972).
Each F-1 engine built by Rocketdyne was a monster, coming in at 19 feet (5.8 m) high, 12.3 feet (3.7 m) wide and weighing 18,500 pounds (8,400 kg). The engines burnt a fuel-oxidizer mixture consisting of RP-1 (kerosene) and liquid oxygen (LOX). The five-engine cluster combined for a total thrust of over 7.5 million pounds-force (33.4 MN). In fact, the Apollo 15 Saturn V generated over 7.8 million pounds-force (34.7 MN) of thrust. For comparison, this total energy output equals over 85 Hoover dams. The F-1 engine remains the most powerful liquid fuel rocket engine ever developed.
A total of 13 Saturn V missions flew from 1967-1973 and all were successful – a powerful testament to the excellent team that Dr. von Braun had assembled in Huntsville, Alabama, which is now known as the Rocket City.
Dr. von Braun provided more details on the success of the Saturn V, stating that “the Saturn V was not overdesigned in the sense that everything was made needlessly strong and heavy. But great care was devoted to identifying the real environment in which each part was to work – and ‘environment’ included accelerations, vibrations, stresses, fatigue loads, pressures, temperatures, humidity, corrosion, and test cycles prior to launch. Test programs were then conducted against somewhat more severe conditions than were expected. A methodology was created to assess each part with a demonstrated reliability figure, such as 0.9999998. Total rocket reliability would then be the product of all these parts reliabilities, and had to remain above the figure of 0.990, or 99 percent. Redundant parts were used whenever necessary to attain this reliability goal.”
First static firing of all F-1 engines. Video courtesy of NASA
Dr. Jim W. Rice, Jr., is an Astrogeologist at the Planetary Science Institute, he has over 25 years research experience specializing on the surface geology and history of water on Mars. Dr. Rice is currently a Co-Investigator and Geology Team Leader on the Mars Exploration Rover Project (Spirit and Opportunity). Rice also has extensive mission experience as Associate Project Scientist on the Lunar Reconnaissance Orbiter and Mars Odyssey Orbiter Projects. He has been involved in Mars landing site selection and certification activities for every NASA Mars Mission since Mars Pathfinder. His career includes working for NASA, Astrogeology Headquarters of the United States Geological Survey, the Mars Spaceflight Facility located at Arizona State University and the Lunar and Planetary Laboratory located at the University of Arizona.