Feeding liquids into a rocket engine
Robert Goddard investigated ways to send rockets higher. In the early 1920s he began experimenting with liquid propellants, using gasoline as fuel and liquid oxygen as oxidiser. Feeding them into a chamber produced gases expelled through a nozzle.
Tanks, lines and the nozzle had to work together. Carrying oxidiser allowed a rocket to operate beyond dense air, while separate storage made propellant delivery a system that could be studied and improved.
A brief flight from an Auburn farm
On March 16, 1926, Goddard erected his rocket on a farm in Auburn, Massachusetts. Its slender structure exposed the engine, tanks and supporting frame. After ignition it left the frame and flew for about 2.5 seconds.
It reached approximately 41 feet, or 12.5 metres, and landed 184 feet, about 56 metres, from the stand. The height and duration were modest, but the liquid-propellant system had propelled a complete rocket into flight.
The diary entry written the next day
Goddard’s diary entry of March 17 described the previous day’s flight, including ascent, change of direction and landing. The launch date and the date of writing are one day apart; photographs and working records also preserve the apparatus and experiment.
Preparation, departure from the stand and landing supplied information for the next design. A short flight yielded observations that could guide changes to structure and propellant delivery.
Developing larger rocket systems
Goddard continued developing liquid engines, controls and rocket structures. Combustion, propellant delivery and attitude changes connected ground tests with flight data. Later orbital and deep-space launch vehicles developed these systems on much larger scales.
The Auburn experiment preserved an early complete liquid-rocket flight. It moved from an engine working on the ground to a vehicle leaving its stand, supplying practical experience of liquid propulsion in flight.