As director of the Jet Propulsion Laboratory at the California Institute of Technology (Caltech) from 1954 to 1976, William Pickering played an important role in the US space programme as it developed in the wake of the Soviet Union’s triumphs with its first Sputnik satellites in 1957. It was a bad time for the American psyche. While rivalry between the separate programmes of the US Navy and Army led to a squandering of effort and technical resources, the Soviet Union suddenly astonished the world with its launch on October 4, 1957, of Sputnik I, a satellite weighing 183lb into an orbit varying between 140 and 590 miles above the Earth.

The Soviet triumph was not simply a technical one, a rivalry between scientists. Radio astronomers and radio hams all over the world feverishly attempted to tune into Sputnik’s bleeps. Newspapers and radio stations carried details of the time and direction of the satellite’s 90-minute orbit, and after nightfall families gazed skywards from their darkened gardens, hoping to catch sight of a totally new phenomenon, a man-created heavenly body.

The Soviet success led to a shift in the popular perception of what had been thought to be a backward country. In impressionable developing countries, it led to a predisposition to respect Soviet achievements in many fields, and to be receptive to Soviet aid such as medicine.

When, little more than a month later, the Soviet Union launched a second satellite, Sputnik II, with a payload of nearly half a ton which included a dog, the famous Laika, there was something approaching panic in the ranks of the American scientists. And then, when on December 6, 1957, the US Naval Research Laboratory’s Vanguard rocket, carrying a satellite weighing less than 3lb blew up on the launch pad, a sense of utter humiliation spread through the American aerospace community.

In this atmosphere, the New Zealand-born Pickering provided a focus of sanity. Deriding official panic and confusion as a “sorry spectacle”, he reminded scientists that the need was not for flashy breakthroughs but “strong leadership, good engineering and good management”.

As head of Caltech’s Jet Propulsion Laboratory, he had a major role in the Explorer satellite project, based on the Army’s Jupiter C rocket, developed by a team led by Wernher von Braun. A degree of face was saved when, on January 31, 1958, the Jupiter C safely lifted off from Cape Canaveral and put the Explorer I satellite into orbit. At 30½lb it was a fraction of the size of the Soviet monsters, but its more sophisticated instruments provided evidence that the Earth was surrounded with the intense bands of radiation known as the Van Allen belts.

At the time it seemed to be a small step on the road back to contention with the Soviet Union in the space race. The Soviet leader Nikita Khrushchev publicly derided the American satellites as “oranges”. When two years later the Soviet Union hit the Moon with a space vehicle, causing further American gloom, Pickering called for an end to military competition for space projects. By that time, of course, Congress had passed the Space Act, which established the National Aeronautical and Space Administration (Nasa). But Pickering’s call gave focus to its work, setting the American space effort on the course which, in 1969, beat the Russians in the race to land a man on the Moon.

William Hayward Pickering was born in Wellington, New Zealand, in 1910. His mother died when he was four and he was sent to live with his father’s parents at Havelock, a quiet fishing village in the Marlborough Sounds at the northern tip of South Island. His elementary education was at Havelock Primary School which had been attended by Ernest Rutherford, father of nuclear physics, thirty years earlier.

From there he went to Wellington College, and had begun a degree at Canterbury University when a wealthy uncle living in California suggested that he come to Caltech, which was already renowned for its aeronautics. He took a bachelors degree in electrical engineering there in 1932, and a masters in 1933. He had wanted to continue his career in New Zealand, but there were no openings at home and he returned to California, taking a PhD in physics at Caltech in 1936, and joining the teaching staff in 1940, after his participation in cosmic ray expeditions to India and Mexico.

During the Second World War he worked on programmes in association with the US Army and Army Air Forces, the first of which was an investigation of Japanese incendiary balloon attacks on the West Coast. This remains one of the odd episodes of the war, possibly sparked by the reaction to a stray Japanese weather balloon over California in the panicky post-Pearl Harbor atmosphere.

Thereafter, with the US Army Air Forces wanting to explore gas turbine technology, in 1944 he moved over to the Caltech jet propulsion lab which was to be the focus of his life’s work. There his expertise was in telemetry and radio control, the basis of his later work with guided missiles and satellites, and in 1945 he became a member of the advisory board of what was shortly to come into being as the USAF.

In 1950 he gave up teaching at Caltech and devoted himself full-time to work at the Jet Propulsion Laboratory, of which he became director in 1954. By that time he was directing a staff of 2,000 scientists and technicians.

The establishment of Nasa in 1958 gave an impetus to the work of the jet propulsion lab, which now came under the agency’s aegis. But it was not until 1962 that it could claim that America had really drawn level with the Soviet Union, with the Mariner II unmanned mission to Venus. Pickering himself regarded the Ranger VII mission of 1964 as the most important step in the race to land a man on the Moon. This was the space flight which returned the first close-up photographs of the lunar surface — several thousand of them — in the last ten minutes before the spacecraft crashed on to it.

The information Ranger VII sent back to Nasa on the composition of the Moon’s surface provided vitally important data for a manned landing, notably dispelling fears that a landing vehicle would sink into a deep layer of dust. Pickering could assure Nasa that men would be able to walk about on the Moon.

Pickering retired from the Jet Propulsion Laboratory in 1976, and spent two years as director of a research institute in Saudi Arabia, before returning to America. By that time he had been awarded Nasa’s Distinguished Service Medal, the US Army’s Distinguished Civilian Service Award and the National Medal of Science. A naturalised US citizen, he had also been appointed an honorary KBE in 1975.

In spite of his years in America, Pickering never lost his characteristic clipped Kiwi accent. Neither did he let slip his links with his native land, and he enjoyed angling both in its creeks and rivers, as well as those of the American West Coast.

He married, in 1932, Muriel Bowler, with whom he had a son and a daughter. She died in 1992 and he married in 1994 Inez Chapman. He is survived by her and by the daughter of his first marriage. His son died two days before him.

William Pickering, aerospace scientist, was born on December 24, 1910. He died on March 15, 2004, aged 93.