structural:scholar_edition
First static tests

Goddard began experimenting with liquid oxidizer, liquid fuel rockets in September 1921, and successfully tested the first liquid propellant engine in November 1923. It had a cylindrical combustion chamber, using impinging jets to mix and atomize liquid oxygen and gasoline.

In 1924–25, Goddard had problems developing a high-pressure piston pump to send fuel to the combustion chamber. He wanted to scale up the experiments, but his funding would not allow such growth. He decided to forgo the pumps and use a pressurized fuel feed system applying pressure to the fuel tank from a tank of inert gas, a technique that is still used today. The liquid oxygen, some of which evaporated, provided its own pressure.

On December 6, 1925, he tested the simpler pressure feed system. He conducted a static test on the firing stand at the Clark University physics laboratory. The engine successfully lifted its own weight in a 27-second test in the static rack. It was a major success for Goddard, proving that a liquid fuel rocket was possible. The test moved Goddard an important step closer to launching a rocket with liquid fuel.

Goddard conducted an additional test in December, and two more in January 1926. After that, he began preparing for a possible launch of the rocket system.