William Pickering

William Hayward Pickering, electrical engineer: born Wellington, New Zealand 24 December 1910; Professor of Electrical Engineering, California Institute of Technology 1946-80 (Emeritus), Director, Jet Propulsion Laboratory 1954-76; Hon KBE 1976; ONZ 2003; married 1932 Muriel Bowler (died 1992; one daughter, and one son deceased), 1994 Inez Chapman; died La Cañada Flintridge, California 15 March 2004.

William Pickering was one of the pioneers of America's space programme, the inspirational driving force behind Nasa's first successful satellite launch and the programme of robotic exploration that eventually sent automated probes to eight of the nine planets in our solar system.

Today, we take for granted the stunning images sent back by rovers on the surface of Mars, but the groundwork that made possible such remote exploration of other worlds was provided by the Jet Propulsion Laboratory (JPL) in Pasadena, California, under Pickering's leadership. Known affectionately as "Mr JPL", he was one of the few public figures to appear twice on the cover of Time magazine and in 1976 earned the rare distinction of receiving an honorary knighthood.

The future rocket man was born in Wellington, New Zealand, in 1910. His mother died when he was six years old and as his father, a pharmacist, was working in the tropics, he was sent to live with his grandparents in Havelock, on the South Island. He later became a boarder at Wellington College, where his interest in science was sparked by his maths teacher, A.C. "Pop" Gifford, who was in charge of the school's observatory. Pickering and his schoolfriend Fred White built an early radio station, using Morse code to communicate with others around the world.

At the age of 19, after Pickering had completed a year of study at Canterbury College, an uncle persuaded him to enrol at the California Institute of Technology (Caltech) in Pasadena, to study electrical engineering. His intention to return to New Zealand after graduation was dashed by the onset of the Depression. Instead, after obtaining bachelor's and master's degrees in electrical engineering, then a PhD in physics, he accepted an instructor's position at Caltech.

During any free time, he enjoyed driving out to the nearby Arroyo Seco dry river-bed and giving a helping hand to a group of engineers and graduate students who were fooling around with primitive rockets under the leadership of Professor Theodore von Karman. The patch of wilderness was grandly dubbed "The Jet Propulsion Laboratory" by the little team of enthusiasts.

The importance of their work became apparent after the outbreak of the Second World War. By then a US citizen, Pickering began working on missile research for the US Army in 1944. He organised the electronics efforts at JPL to support guided-missile research and development, becoming project manager for Corporal, the first operational missile developed by JPL. The Sergeant solid-fuel missile was later developed under his direction. In an interview in 1994, Pickering joked about the trials and tribulations of testing the early guidance systems:

For the 100th Corporal that we tested, I pushed the [launch] button, and the darn thing went east instead of north. I never pushed the button again.

After becoming professor in charge of radio and electronics in 1946, Pickering was appointed to the Scientific Advisory Board of the United States Air Force. He had his first meeting with the legendary Nazi rocket scientist Wernher von Braun when he joined a group of American scientists who went to the New Mexico desert to study the German V-2 missile. Appointed director of the modest JPL site in 1954, Pickering continued to work alongside the German émigrés, developing ever larger and more powerful rockets. This collaboration paid dividends 11 years later, when von Braun's group teamed up with JPL to salvage American pride after the Soviet Union stunned the world with the launch of Sputnik, the first artificial satellite.

Faced with public humiliation when the US Navy's Vanguard rocket exploded on lift-off, President Dwight D. Eisenhower called upon JPL and the Army Ballistic Missile Agency to place the first American satellite into orbit. Pickering directed the JPL effort, which, in just 83 days, provided the 14kg satellite, a network of tracking stations and the upper stages of the Jupiter-C rocket that lofted Explorer 1 into orbit on 31 January 1958. Pickering later described the seemingly interminable wait for confirmation that the satellite had successfully entered orbit. He recalled:

At the designated time, I phoned JPL, and they had a phone link to the tracking station in the desert. The time went by, and went by, and no signal. It was eight minutes before we got a signal, and it was the longest eight minutes of my life.

Now a national hero, Pickering posed for the clamouring photographers alongside von Braun and the scientist James Van Allen. The icing on the cake came when the Geiger counter on board Explorer 1 discovered a belt of intense radiation around the planet. Pioneer III, a modified Explorer launched in December 1958, discovered a second, higher radiation belt when it reached an altitude of 63,000 miles.

In 1958, JPL was transferred from the army to the newly created National Aeronautics and Space Administration (Nasa). Given the choice of leading either human or robotic space exploration for Nasa, Pickering chose the latter. Although the new administrative marriage opened up exciting opportunities to explore other worlds, Pickering was determined to assume control of Nasa's lunar and planetary programme, with the result that relations with the new supervisors in Washington DC were often strained.

Building on the success of Explorer 1, JPL began to consider a number of increasingly ambitious programmes, including Ranger and Surveyor missions to the Moon, and Mariner missions to the planets.

The lunar programme got off to an inauspicious start, when a rocket failure stranded Ranger 1 in Earth orbit. The next five Ranger missions also flopped, piling immense pressure on Pickering and his team. The ghost was finally laid to rest on 31 July 1964, when Ranger 7 sent back the first close-up pictures of the cratered lunar surface during the final minutes of its suicidal voyage. Altogether, more than 17,000 photographs of the Moon were returned by the three successful Ranger probes.

Preparations for the Apollo landings continued with the Lunar Orbiter and Surveyor probes to the Moon, returning pictures and digging into the dust to show that manned spacecraft could touch down safely on the lunar surface.

Meanwhile, JPL had been leapfrogging the Soviet Union in the exploration of Earth's neighbouring planets, Mars and Venus. On 14 December 1962, the Mariner 2 spacecraft completed the first successful flyby of another planet when it swept past Venus after a journey of more than 180 million miles. Pickering was rewarded with his picture on the cover of Time magazine.

On 14 July 1965, after a 228-day voyage of more than 325 million miles, Mariner 4 became the first spacecraft to send back close-up pictures of Mars. The achievement earned Pickering his second appearance on the cover of Time, to the delight of the normally reserved engineer. Unfortunately, much to everyone's disappointment, the 20 grainy, black-and-white images displayed a Moon-like, barren, cratered surface. Only in 1971, when Mariner 9 became the first spacecraft to orbit another planet, was Mars revealed as a world of huge volcanoes, giant canyons and mysterious dry channels once carved by running water.

Pickering retired from JPL in 1976, after 22 years as director. He returned briefly to Caltech, before taking up a two-year teaching post at the University of Petroleum and Minerals in Saudi Arabia. At the age of 68 he returned to the United States with the intention of working on a commercial venture into solar energy. Instead, he founded his own company to manufacture compressed fuel pellets for home space heaters, artificial fireplace logs, campfire starters and animal bedding from sawdust. However, Pickering never lost his interest in space and was at JPL in January 2004 when the Spirit and Opportunity rovers landed on Mars.

Pickering received numerous awards throughout his career, including Nasa's Distinguished Service Medal. In 1975, he was awarded the National Medal of Science by President Gerald Ford, followed the next year by an honorary knighthood. Pickering maintained close ties with his native land and in 2003 was appointed to the Order of New Zealand, the country's highest honour.

Peter Bond