The achievements of the pioneering American rocket scientist Max Hunter, who died on November 10th aged 79, were recognised 12 years ago by the United States National Space Society in a special award for "a lifelong contribution to the field of rockets, missiles and spaceflight".
But the appreciation proved a touch premature because, as he continued to work on the design of rockets, he was instrumental in selling the Star Wars strategic defence initiative idea to President Reagan. In papers he left behind, he also provided the latest versions of a launcher to replace the space shuttle, an idea he first outlined to colleagues in 1985.
The designs he championed were based on an approach known as single-stage-to-orbit (SSTO) as the best way to build cheap, reusable launch vehicles. He believed that, in turn, could open the way for mass space tourism, with a chain of orbiting space hotels, leading eventually to vacation sites on the moon.
An adviser on space policy to both presidents Kennedy and Lyndon Johnson, Max Hunter was born in Hollidaysburg, Pennsylvania. He graduated in physics and mathematics from that state's Washington and Jefferson College, and, in 1944, got a Ph.D., in aeronautical engineering from the Massachusetts Institute of Technology.
He was recruited by Douglas Aircraft, in Santa Monica, California, to work on the design of experimental versions of two of the company's B-42 and B-43 bombers, and then transferred to the team starting missile development.
As chief design engineer, he was involved in the development of the Honest John, Thor, Nike-Zeus and other cold war missiles; and, as chief engineer of space systems, was responsible for all Douglas space efforts, including the Delta launch vehicle and the Saturn S-IV stage of the Apollo moon programme.
He stayed with Douglas until 1961 when he joined the National Aeronautics and Space Council, the panel that advised the US federal government on space projects. In 1965, he returned to industry, joining the Lockheed Missiles and Space company, where he was responsible for the design of advanced space transport vehicles, developing the use of expendable tanks in the space shuttle, and steering the Hubble space telescope through its early stages.
On retirement in 1987, he formed his own consulting firm, SpaceGuild Inc, in Sunnyvale, California. By then, he was thinking about a replacement for the space shuttle; indeed, following the loss of the Challenger and its seven astronauts in 1986, he had written a paper on the need to replace the shuttle with a less expensive launch system.
The title of that paper, "The Opportunity", referred to what he saw as a classic entrepreneurial opportunity in space commerce, the key to whose exploitation was cheap space transport and a lower-cost shuttle replacement. He argued, "such a new vehicle should not cost much more per pound to develop than an experimental airplane and possess airplane-class safety".
His target was to design a generation of space boosters that would cut the cost of going into orbit from about $10,000 per pound to something closer to $100 per pound, thus opening up a market for space travel to the sort of holidaymakers who presently go on round-the-world cruises and adventure jaunts to Antarctica.
The debate was, and remains, over the possibility of building a rocket booster that can place payloads of, say, 10 or 20 tons, in orbit in one leap. The argument boils down to the SSTO school versus the TSTO (two-stages-to-orbit) school, which requires an extra set of engines to get it off the ground. Max Hunter believed that with modern, lightweight materials and ultra-miniaturised electronics, SSTO was more practical than the TSTO approach. He called his design SSX, or space-ship-experimental.
He was always eager to promote the ideas of young enthusiasts, and his interest ensured the early recognition of a mathematics graduate student, Michael Minovitch, which started a revolution in the design of interplanetary space missions. Hired for a vacation job at Nasa's Jet Propulsion Laboratory (JPL) in Pasadena, California, Minovitch wondered if a planet's gravity could be used to provide a "kick" to a passing spacecraft.
He showed how to design a trajectory to a target planet in such a way that a "gravity-assist" could be obtained from one planet to propel a craft on towards another. A similar boost could be obtained from the second planet to go on to a third, and so on. The only energy required would be the launch from earth to the first planet. In 1965, the idea was adopted for what became the Voyager Project, including the grand tour of the outer planets by Voyager 2, launched in 1977.
Max Hunter is survived by his second wife Irene, three sons and two daughters.
Maxwell White Hunter: born 1922; died, November 2001