Liquid and Solid Rockets

As he sought to develop operational rockets, U.S. scientist Dr. Robert Goddard found in the early years of the 20th century that many people rejected his ideas as fantastic. Some opponents insisted rockets would not operate in the vacuum of space. They said there would be no air to push against and no air to sustain the burning of the rocket fuel once a spacecraft reached the vacuum of space.

Liquid Rocket Fuel

On the first point, Goddard believed Newton’s theories of action, reaction, and unbalanced forces were universal.

On the second point, his answer was to take along the needed oxygen in extremely cold liquid form plus a liquid fuel, such as kerosene, and pump the two together into a combustion chamber. He proved both points initially in his laboratory. The test device not only operated in a vacuum but actually operated more efficiently—with more thrust per pound of propellant—than in the normal air outside.

Goddard successfully launched the world’s first liquid-fuel rocket in Massachusetts in 1926. Rudimentary by today’s standards, the rocket was ignited by a blowtorch and flew about 184 feet in two-and-a-half seconds.

Today’s mighty space launch vehicles are, in principle, refinements of Goddard’s simplistic rocket.