Willy Ley was a world-renown expert in and proponent of rocketry and space travel. Born in Berlin, Germany on October 2, 1906, Ley attended the Universities of Berlin and Konigsberg and studied astronomy, paleontology, zoology and physics. Beyond these studies however, he developed a passionate interest in rocketry and its potential applications for space travel. Accordingly, he wrote and published his first book, Die Fahrt in den Weltraum (Travel in Outer Space) in 1926 and helped found Germany's early rocketry and spaceflight club, Verein fur Raumschiffahrt or VfR (Society for Space Travel) the following year. In 1929, Ley, along with well-known rocketry theorist Hermann Oberth, acted as a technical consultant on Fritz Lang's film, Frau im Mond (Woman in the Moon). Throughout the late 1920s and early 1930s, he continued to write books, as well as numerous articles in German and foreign publications, on the subject of rockets and spaceflight. Once Adolf Hitler took power in 1933, the Nazis pressured Ley to cease publishing his articles in foreign journals and magazines due to rocketry's potential as a weapon in Germany's arsenal. Also, the VfR disbanded during the Nazis' first year in power amid concerns among the membership regarding the interest the German military was taking in their activities. These factors compelled Ley to leave Germany for Britain briefly and then to the U.S. in 1935. He became an American citizen in 1944.

Until World War II, Ley focused his writing career on topics unrelated to rocketry and space travel. He discovered little interest in these fields among the U.S. public. He was successful though, with a number of non-space publications such as Salamanders and Other Wonders and The Lungfish, the Dodo and the Unicorn. From 1940-44, Ley was science editor of the New York newspaper, PM and later lectured as a professor at Fairleigh Dickinson University in New Jersey. He was also a regular contributor to a myriad of magazines, encyclopedias and digests such as Popular Mechanics, Cowles Encyclopedia and Galaxy. However, once World War II began and especially after Germany launched V-2 missile attacks on Britain in 1944, Ley found himself in great demand as an expert in rocketry. Following the end of the war, his writings, lectures and newspaper, radio and television interviews helped to spur even greater public interest in rockets and their potential for space flight. Additionally, his books on this subject were widely read in the U.S. and around the world. First published in 1944, Ley's Rockets, Missiles, & Space Travel enjoyed a great deal of popularity and justified numerous printings of revised editions. Other highly successful titles that Ley produced during the 1950s and 1960s included The Conquest of Space, The Conquest of the Moon (written with Wernher von Braun and astronomer Fred Whipple) and Beyond the Solar System. Ley, along with von Braun, artist Chesley Bonestell and others, collaborated on a series of space-themed issues of Collier's (1952-54) that helped to foster popular support for future U.S. missions to earth orbit, the moon and the planets.

Aside from his busy career as a prolific author and populizer of rockets and space travel, Ley was also a husband and father of two children. His wife, Olga, was an accomplished ballet dancer, model and author in her own right. The couple had to two daughters, Sandra and Xenia. Ley had hoped to attend the Apollo 11 launch at the Kennedy Space Center in Florida but died of a heart attack at his home in Jackson Heights, New York, on June 24, 1969. His death came only four weeks before the launch of mankind's first landing on the moon's surface.