The most powerful solid-fuel rockets ever built for space travel were the solid rocket boosters on the space shuttle. Each booster could generate nearly three million pounds of thrust. When coupled with the space shuttle orbiter’s three rocket engines, each capable of generating about half a million pounds of thrust, the total space shuttle launch system generated a maximum thrust of about seven million pounds—almost as much as the Saturn V.

The scientist generally considered to be the most influential figure in the American space program was the German physicist Wernher von Braun (1912–1977). Born into a wealthy family, von Braun became an amateur astronomer at an early age, and studied at the University of Berlin. One of his mentors was the German rocketry pioneer Hermann Oberth (1894–1989). Soon after the Nazis came to power in Germany, von Braun was placed in charge of research and development of rockets as weapons for the German military. Under his leadership, the Germans developed the V-2 rocket, the first long-range, rocket-launched missile weapon system.

Near the end of World War II, von Braun and 126 other German scientists were hired by the U.S. government and brought to America under the code name Project Paperclip. Using captured German rockets, the scientists taught their American counterparts about their rocketry; they also continued their rocket research and test flights at White Sands Proving Grounds in New Mexico, and at Fort Bliss in Texas. A few years later, they were moved to NASA’s Marshall Space Flight Center in Huntsville, Alabama. There, von Braun was named the center’s first director and presided over the construction of a new long-range ballistic missile called the Redstone. Eventually, von Braun led the effort to create the Jupiter-C—the first American rocket capable of launching spacecraft. This rocket launched America’s first satellite into orbit, Explorer 1. It was followed by the Saturn V, which was used to launch the Apollo manned missions to the Moon.