The same week she arrived, another new hire started at the lab named Conway Snyder. Born in Missouri, Snyder graduated from high school in Redlands, Calif., earning degrees at the University of Redlands and in Iowa. During World War II he worked on the Manhattan Project, witnessing the first atomic bomb test in person. After earning a Ph.D. at Caltech, he held various jobs on the east coast before coming to JPL.
Snyder, about 15 years older, led a very small group that included Marcia Neugebauer as well as Richard Davies. Their section was called "Physics"; later, the name was changed to "Physics and Chemistry." Only much later was a Science Division created at JPL.
At first, the minuscule group did studies on nuclear propulsion for rockets, investigating questions involved in heating gases in fission reactors. When plans for such rockets were scrapped, the group looked for other science questions. Ionized gases seemed like a natural topic to tackle. From there it was a short hop to investigating the hypothesized solar wind.
Eventually, Marcia's husband began working at JPL. Gerry Neugebauer had the obligation of working off his ROTC time commitment after completing his doctorate at Caltech in 1960. The Army assigned him to JPL to help evaluate science payloads for space missions.
Another young face in JPL's growing stable of scientists was Ed Smith. A Los Angeles native, Smith earned bachelor's, master's and doctoral degrees at UCLA. In the 1950s he worked for aerospace firms such as Northrop Aircraft and TRW's predecessor company. Urged by NASA to build up its cadre of on-site scientists, JPL hired Smith in 1961, just as the Mariner Venus mission was taking shape.
With a green light from Washington, project manager Jack James returned to Pasadena to get the mission done. All told, three spacecraft would be built – two to be launched to Venus, and a third as a spare.
In those days, JPL was smaller — with about 2,200 employees — and less formal. Many employees worked on one project and then another in quick succession; most who helped design and build the first Mariners were also putting in time on the Rangers. All told, about 250 JPL employees would work on the Venus project, supported by 34 subcontractors and more than 1,000 parts suppliers. By the time they were done, Mariner 1-2 required 2,360 work-years and $47 million to accomplish. At the time it seemed large, though by later standards even with inflation it was relatively small.
Though NASA Headquarters was reluctant to cede control over science payloads, the breakneck schedule for Mariner 1-2 meant that JPL was given more of a say in order to move the project forward. The tight timing was advantageous for local scientists. Marcia Neugebauer recalls that she and Conway Snyder had built an instrument to prove or disprove the existence of the solar wind, and were looking for missions it could fly on. It was selected for the first Rangers, but Neugebauer and Snyder assumed that a competing instrument from an east coast university would edge them out for Mariner Venus. It turned out, though, that the competing professor was out of the country when the quickturnaround call for proposals was issued. The JPL-developed solar plasma instrument thus got the nod.
At a previous job in industry, Ed Smith had worked with scientists who later went to NASA. When the call for Mariner Venus experiments came out, it was natural that they would collaborate on an instrument to search for a magnetic field at Venus.
Another instrument, an infrared radiometer, was placed on the spacecraft mostly to help find Venus. Since it was onboard, project managers reasoned that it might as well be used to do science. Lewis Kaplan, a one-time U.S. Weather Service meteorologist who joined the JPL staff to conduct research on atmospheres, became its lead scientist, supported by Carl Sagan and Gerry Neugebauer. Working on the radiometer changed Gerry's career path from high-energy physics to infrared astronomy, a field in which he was later to achieve fame.
Hugh Anderson, a young scientist who had just earned his Ph.D. at Caltech and was working at JPL, saw Mariner Venus as an ideal oppportunity
to fly an experiment to measure high-energy radiation entering the solar system from more remote regions of the galaxy. He persuaded Caltech faculty member Victor Neher to join him. Neher was famous for having invented an ion chamber to measure such radiation.
Despite the strong presence by the home team, not all of the science on Mariner 1-2 was heavily canted toward JPL and Caltech. The spacecraft's microwave radiometer, which would make critical measurements to determine how hot Venus really was, was led by a scientist from MIT — but even that team included Doug Jones, a JPL scientist who was adept at building instruments.
James Van Allen, the Iowa scientist who used Explorer 1 to discover Earth's radiation belts, would put a similar experiment on the Mariners. A scientist from NASA's Goddard Space Flight Center was responsible for an instrument to detect dust particles between the planets. Even so, many outside scientists felt the mission featured too much home-grown science, and they lobbied forcefully for later missions to cast a wider net.
All of that science had to fit in small packages. Launched by the less powerful Agena upper stage booster, Mariner Venus could weigh only 447 pounds. At first, only 25 pounds was set aside for the entire science payload. Later, it was bumped up to 46 pounds. Project manager Jack James later recalled he was "considered sort of an ogre" in the science community, due to his insistence on control of the instruments going onto the spacecraft.
One instrument absent from Mariner was a camera. Years later, Sagan recalled there were debates about whether to include one, and he was among those lobbying in favor. Sagan was a believer in using science instruments to make serendipitous discoveries. By contrast, more conservative scientists argued that every experiment must be tailored to answer a specific question stated in advance. In the end, the fact that the photographic technology of the era probably wouldn't reveal much, given Venus' cloud cover, meant that Mariner carried no camera.
Adapted from the Rangers, the spacecraft were built around a six-sided box. A tubular structure that one newspaper reporter likened to an oil derrick was mounted atop the hexagon; it would serve to isolate instruments