In 1919, Goddard wrote a scientific article, "A Method of Reaching Extreme Altitudes," describing a high-altitude rocket; this ground-breaking article was published in a Smithsonian report. Misunderstanding the article completely, the New York Times newspaper ridiculed Goddard in a Jan. 13, 1920, editorial, stating that space travel was impossible, and that Goddard "seems to lack the knowledge ladled out daily in high schools." They stated that rocket thrust would not work in a vacuum, apparently believing that Newton's Third Law (that every force has an equal and opposite reaction) was not valid in space. The NY Times did not print a retraction until 3 days before men landed on the moon (p. 43, July 17, 1969).

After many years of failed attempts and public ridicule, Goddard's first successful rocket was launched on March 16, 1926, from a relative's farm in Auburn, Massachusetts. It was a liquid-fueled 10-ft. rocket that he called Nell. The flight lasted 2 1/2 seconds; the rocket flew a distance of 184 feet and achieved an altitude of 41 feet.

In 1929, Goddard launched the first scientific payload (a barometer and a camera) aboard a rocket flight.

Meanwhile in Germany, the German Rocket Society was formed in 1927, and the German Army began a rocket program in 1931. In the USA, Goddard received almost no support from the US government, which did not yet understand the importance of rocketry. The German government paid much more attention to Goddard's work than the US government did.

Goddard soon moved to Roswell, New Mexico, where he developed more sophisticated multi-stage rockets, rockets with fins (vanes) to steer them (1932), a gyroscope control device for rocket control (1932), and supersonic rockets (March 8, 1935). In 1937, Goddard launched the first rocket with a pivotable motor on a gimbal (a ring on an axis that permits an object to remain upright even when its support is tipped) using his gyroscope directional control device. Altogether, Robert Goddard developed 214 patents.

In an autobiographical essay, Goddard wrote that as a teenager, "on the afternoon of October 19, 1899, I climbed a tall cherry tree and, armed with a saw which I still have, and a hatchet, started to trim the dead limbs from the cherry tree. It was one of the quiet, colorful afternoons of sheer beauty which we have in October in New England, and as I looked towards the fields at the east, I imagined how wonderful it would be to make some device which had even the possibility of ascending to Mars. I was a different boy when I descended the tree from when I ascended for existence at last seemed very purposive."