March 16, 1926: The First Liquid-Propellant Rocket Launch

This series contains materials relating to the flight of March 16, 1926, in which Robert Hutchings Goddard successfully launched the world's first liquid-propellant rocket (fueled with liquid oxygen and gasoline). Goddard had been working to achieve liquid-fuel propulsion since 1921 and had written about its feasibility since 1909. As described by David Clary in Rocket Man: Robert H. Goddard and the Birth of the Space Age:

"There were two major technical problems. One was that the combustion chamber would have to receive, mix, and burn the fuel and oxidizer, and exhaust the combustion gases, in an efficient manner; a chamber for solid fuels was comparatively simple. The other challenge was to find a way to feed the fuel and oxidizer into the chamber; this required pressure..."

After years of developing pumps as a means to achieve the necessary pressure, a successful static test on December 6, 1925 was conducted, resulting in the first liquid-fuel rocket to successfully operate and lift its own weight. However, Goddard observed that while the present model could lift, it would not create a successful launch at its current weight. With the pressure of producing a successful flight mounting, Goddard made a major pivot and discarded the pumps and engines in favor of a pressure-fed system. He would make something with little practical value for future innovation, but that provided the innovation he needed to produce a historic result. Many sources incorrectly claim that forgoing the pumps and engines is the breakthrough that made the December 6, 1926 lift possible, but this is untrue (the David Clary book is accurate). Goddard writes in both his diary and subsequent reports about using pumps and engines in the December 6 test, as well as the realization that he would need to eliminate them in order to produce a light enough rocket to achieve that first launch.

During this time, continued financial support could be shaky and uncertain, not to mention that LOX (liquid oxygen) was difficult to regularly obtain, store, and use. Before landing on gasoline for the choice of fuel, Goddard tried working with several different options, including ether, a gasoline-ether mixture, glycerin, and ammonium nitrate. The pressure produced from vaporized LOX (the burning process was sped up by placing cotton in a cup of alcohol under the LOX tank) pushes each liquid from its tank, through separate pipes, and into the combustion chamber for mixing and burning. These fuel lines held the rocket together. To keep the pressure even, cork floats were placed in the tanks. Interestingly, the motor resided at the top of the rocket, as Goddard initially believed having the motor upfront would improve its directional stability.

The flight took place at "Aunt Effie's" (a distant relative of Goddard's) Ward Farm in Auburn Massachusetts, where he conducted rocket experiments until 1929. Clary describes that assistant Henry Sachs "lit a blowtorch attached to a long stick, and touched off the igniter, improvised from match heads, at the top of the motor. Then he lit the alcohol tank under the LOX tank and stepped behind a propped-up wooden door for shelter. Goddard turned a valve, which let pressurized oxygen from a tank enter the fuel system, donating a boost to the vapor pressure rising from the LOX tank, heated by the alcohol flame."

As Goddard next described it, "Even though the release was pulled, the rocket did not rise at first, but the flame came out and there was a steady roar. After a number of seconds it rose, slowly until it cleared the frame, and then at express-train speed, curving over to the left, and striking the ice and snow, still going at a rapid rate. It looked almost magical as it rose, without any appreciably greater noise or flame, as if it said, 'I've been here long enough; I think I'll be going somewhere else if you don't mind'".

The delay in lift-off and very limited film length prevented Esther from capturing the flight with her new movie camera. That brief 16mm film footage can be seen here, as part of the Goddard Rocket Film Reels series. While the flight itself was not captured by photograph or video, Esther was able to record before the flight, assistant Henry Sachs igniting the rocket, and after the flight.

The rocket's altitude was 41 feet at an average of 60 miles per hour; it was in the air for 2.5 seconds and landed 184 feet from the launching frame, traveling a total path of 220 feet.

In his "Report on the Development of Liquid Propelled Rocket", Goddard provided photographs of every newly developed part and/or component; he did not take photographs of every minor adjustment or iteration made (for example the many variances of width, diameter, thickness and length of various materials). Every photograph of a rocket component aligning with the March 16, 1926 launch has been included in this series. This is the first time photographs of these rocket parts have been made available for online viewing, and together they make up the closest and most granular visual documentation of the March 16, 1926 rocket's construction that there is.

All collection descriptions written by Katie Stebbins, Digital Projects Librarian.