Ernst Stuhlinger: Rocket scientist who helped the US become the leading space power

Ernst Stuhlinger was one of the most talented members of the German group of rocket scientists who developed the V-2 missile and subsequently played a key role in most of the major events that led to the birth of the Space Age and enabled their adopted country, the United States, to become the world's leading space power.

While he was an infantryman engaged in a life-and-death struggle on the Eastern Front during the Second World War, Stuhlinger's life was transformed by an event which took place many hundreds of miles away from the front line. On 3 October 1942, a stubby, dart-shaped missile blasted off from Peenemünde in the Baltic Sea. The A-4 vehicle, later to become the infamous V-2 "vengeance weapon", soared to a height of 29,500 feet before plunging into the sea 118 miles from the launch site. Following this first, historic, launch, the German rocket programme expanded rapidly, and one of the specialists recruited from the armed forces to Wernher von Braun's rocket team was the 29-year-old physicist Stuhlinger.

At the end of the war, many of von Braun's team handed themselves over to the American forces. Eager to gain access to their unrivalled knowledge and expertise, the US government put in motion a secret operation to relocate leading members of the team to Texas.

Over the following decades, it was von Braun's rocketeers who became the keystone of America's efforts to gain technological supremacy in its Cold War rivalry with the Soviet Union, and who enabled the United States to win the race to the Moon. One of the architects of this success was Stuhlinger, and, 26 years after he first joined von Braun's group, he watched proudly as the ghostly figure of Neil Armstrong made a "giant leap for mankind".

Stuhlinger was born in 1913, in Niederrimbach, Germany. He was educated at the University of Tübingen, where he earned a doctorate in physics in 1936. Over the next five years he worked as an assistant professor at the Berlin Institute of Technology, specialising in studies of nuclear physics and cosmic rays as part of the German atomic research programme.

In 1941 he was sent to the Russian front as an infantry soldier. He was one of the few in his unit to survive the Battle of Stalingrad. In 1943, he was put in charge of a group that evaluated flight data acquired during development tests in order to improve the guidance and control systems of the V-2. As the Allies advanced, many of von Braun's leading scientists and technicians were forcibly relocated to southern Germany. Separated from the main group, Stuhlinger and 20 colleagues were in hiding near Weimar when the war in Europe ended. Several weeks passed before they were informed that von Braun's group had surrendered to the Americans.

During the top secret Operation Paperclip, Stuhlinger became one of 112 German scientists and engineers taken to the United States to work on rocketry and missile development. Between 1946 and 1951, the German contingent, based at Fort Bliss, Texas, enabled the Army Ordnance Corps to test fire some 70 V-2 rockets. "We called ourselves PoPs – prisoners of peace," Stuhlinger recalled. In 1950, the group was resettled in Huntsville, Alabama, where they continued to develop larger, more powerful rockets at the Army Ballistic Missile Agency's Redstone Arsenal.

As head of the Research Projects Office at the Redstone Arsenal, he oversaw work including Project Orbiter, an effort to launch an Earth-orbiting satellite on one of Von Braun's missiles. Although the Navy's Vanguard rocket was given priority in 1955, the Huntsville team continued to develop the Redstone with a view to using it as a space launcher.

In October 1957, after the astounding news that the Soviet Union had successfully launched Sputnik, the world's first artificial satellite, the US response began with the embarrassing failure of the Vanguard. Von Braun's obsession with developing powerful, multi-stage rockets that could be used as satellite launchers paid off when the Eisenhower administration turned to his group to restore American prestige. "I immediately felt a kind of thankfulness to the Russian colleagues because it was a wonderful wake-up call for us Americans," Stuhlinger commented.

On 31 January 1958, only 16 weeks after Sputnik's dramatic success, von Braun's team was able to launch the Explorer 1 satellite on a modified Army Jupiter-C rocket. Under pressure to prepare America's reply, Stuhlinger closeted himself in his garage at home and, in a matter of hours, created a simple, but effective timing device to initiate firing of the Jupiter-C's second stage. Following lift-off from Cape Canaveral, Florida, Stuhlinger was responsible for pressing the firing button that would start second stage ignition at just the right moment. This led to him being called "the man with the golden finger".

Stuhlinger also played a part in ensuring that Explorer 1 made scientific history. During his time at Princeton in 1953-54, he enjoyed long discussions with James Van Allen about the possibility of placing an experiment on an American satellite. Although the Vanguard was the government's preferred launcher, Van Allen hedged his bets by keeping in contact with Stuhlinger and ensuring that his experiment would also fit on the Army's Jupiter-C. After Vanguard's failure, Van Allen was able to fly his experiment on Explorer 1, leading to the discovery of radiation belts around the Earth.

Stuhlinger was also one of the early proponents of solar-electric propulsion systems for use in spacecraft. Inspired by the 1939 book Possibilities of Space Flight, written by the German pioneer Herman Oberth, Stuhlinger began to study the possibility of replacing inefficient chemical rocket engines with ion engines that could accelerate electrically charged gases to very high velocities without the need for high temperatures. In 1955, he presented a paper at the International Astronautical Congress in Vienna entitled "Possibilities of Electrical Space Ship Propulsion", and his interest in this new technology helped to ensure its widespread adoption in modern unmanned space missions.

During much of the 1960s, Stuhlinger was director of the Marshall Space Flight Centre Space Sciences Laboratory. In 1968, with the Apollo Moon programme in full swing, he was promoted to Associate Director for Science. As such, he was heavily involved in the early planning for lunar exploration, helping to design the guidance and navigation systems on the world's largest launch vehicle, the Saturn V. Looking forward to the post-Apollo era, he oversaw development of the solar X-ray telescope which flew on the Skylab space station (1973-74) and produced a wealth of new information about the Sun.

During his later years, Stuhlinger attempted to address the historic legacy of the V-2 era. In a 1995 article for The Huntsville Times, he called the Nazi era "extremely deplorable", but he continued to maintain that the team of German rocket engineers had been driven by the dream of space travel, rather than the development of weapons.

Peter Bond

Ernst Stuhlinger, physicist: born Niederrimbach, Germany 19 December 1913; Director, Space Sciences Laboratory, George C. Marshall Space Flight Center, Nasa 1960-68, Associate Director for Science 1968-75; married 1950 Irmgard Lotze (two sons, one daughter); died Huntsville, Alabama 25 May 2008.