“It was much more in line with what I was doing and what I was interested in at the time,” he recalls. A chance encounter with imaging team lead Brad Smith on an airline flight led them to strike up a conversation, and then a long-term friendship, that got Rich an invitation to be a full-fledged member of the imaging team from Saturn onward. He and Brad used the IRTF andother telescopes around the world to make observations in support of Voyager ’s giant-planet flybys, and they have continued their long-term collaboration beyond Voyager. For example, they collaborated on a telescopic observation campaign that led to the discovery of the first “circumstellar disk” of dust and gas—a nascent solar system in the making—around the nearby star Beta Pictoris.
Heidi Hammel was a graduate student at the University of Hawaii in the mid-1980s and was doing her thesis research using the 88, collecting color filter images of the atmospheres of the giant planets. With the impending Voyager 2 flybys of Uranus and Neptune, she was focusing on telescopic observations of those two worlds, and especially on Neptune, which showed cloud features that could be monitored from Earth.
“With my Neptune work, we were trying to establish what the winds of the planet were like,” she told me. “Back in those days, we didn’t know what the wind speeds were, or even what the exact rotation rate of the planet was. But my thesis advisor, Dale Cruikshank, and I knew that the Voyager team would need this kind of information for planning the imaging sequences.”
Heidi’s results were different from previous studies, and she recalls Dale having her give a “dark, backroom” presentation about her results to Voyager imaging team leader Brad Smith and Rich Terrile. She made her case for them to use her results, rather than those from Smith and Terrile’s own observations, to plan what images Voyager should take.
“I laid out my data on the table, I explained what I did, and I showed how their rotation period just didn’t fit the data,” she remembers. “I was still a graduate student, and here I was—petrified—pitching this to the head of the Voyager imaging team! When I was done, they just kind of looked at it, and they looked at me, and they said, ‘Well, looks like you’re right.’”
Smith was impressed enough, apparently, that after Heidi finished her PhD research, he invited her to be a member of the Voyager imaging team at JPL.
LEAVING EARTH
Just before they were launched in 1977, what would have been Mariner 11 and Mariner 12 if the earlier naming series had continued, the spacecraft were officially renamed Voyager 1 and Voyager 2 , partly in recognition of their radically different outer-solar-system missions, and partly because between 1972 and 1977 the spacecraft design hadsignificantly changed from the original Mariner configuration.
Once the spacecraft is built and has been tested and proven to be ready for the harsh environment of space, and once its mission and trajectory are defined, someone then has to figure out how to strap it onto a rocket and launch it off the planet. Whenever I’d tried as a kid to launch a small automated film camera “spaceship” on the top of my model rockets, the extra weight proved too much for the engines to lift, and they would either fizzle out or tip over and skip across the lawn (even my monster “Saturn V” model, with five Estes “D” engines, couldn’t get more than two feet off the ground!). The lesson I learned, that I now know professional rocket designers have to live by, is that for any given kind of rocket, there is a limit tohow much mass can be lifted and accelerated to the required speed, and that mass limit can be only a very small fraction of the rocket’s total mass.
In the case of the Voyagers, each spacecraft weighed in at around 1,600 pounds (with about 15 percent of that making up the science instruments) and had to be accelerated to more than
Heidi Hammel was a graduate student at the University of Hawaii in the mid-1980s and was doing her thesis research using the 88, collecting color filter images of the atmospheres of the giant planets. With the impending Voyager 2 flybys of Uranus and Neptune, she was focusing on telescopic observations of those two worlds, and especially on Neptune, which showed cloud features that could be monitored from Earth.
“With my Neptune work, we were trying to establish what the winds of the planet were like,” she told me. “Back in those days, we didn’t know what the wind speeds were, or even what the exact rotation rate of the planet was. But my thesis advisor, Dale Cruikshank, and I knew that the Voyager team would need this kind of information for planning the imaging sequences.”
Heidi’s results were different from previous studies, and she recalls Dale having her give a “dark, backroom” presentation about her results to Voyager imaging team leader Brad Smith and Rich Terrile. She made her case for them to use her results, rather than those from Smith and Terrile’s own observations, to plan what images Voyager should take.
“I laid out my data on the table, I explained what I did, and I showed how their rotation period just didn’t fit the data,” she remembers. “I was still a graduate student, and here I was—petrified—pitching this to the head of the Voyager imaging team! When I was done, they just kind of looked at it, and they looked at me, and they said, ‘Well, looks like you’re right.’”
Smith was impressed enough, apparently, that after Heidi finished her PhD research, he invited her to be a member of the Voyager imaging team at JPL.
LEAVING EARTH
Just before they were launched in 1977, what would have been Mariner 11 and Mariner 12 if the earlier naming series had continued, the spacecraft were officially renamed Voyager 1 and Voyager 2 , partly in recognition of their radically different outer-solar-system missions, and partly because between 1972 and 1977 the spacecraft design hadsignificantly changed from the original Mariner configuration.
Once the spacecraft is built and has been tested and proven to be ready for the harsh environment of space, and once its mission and trajectory are defined, someone then has to figure out how to strap it onto a rocket and launch it off the planet. Whenever I’d tried as a kid to launch a small automated film camera “spaceship” on the top of my model rockets, the extra weight proved too much for the engines to lift, and they would either fizzle out or tip over and skip across the lawn (even my monster “Saturn V” model, with five Estes “D” engines, couldn’t get more than two feet off the ground!). The lesson I learned, that I now know professional rocket designers have to live by, is that for any given kind of rocket, there is a limit tohow much mass can be lifted and accelerated to the required speed, and that mass limit can be only a very small fraction of the rocket’s total mass.
In the case of the Voyagers, each spacecraft weighed in at around 1,600 pounds (with about 15 percent of that making up the science instruments) and had to be accelerated to more than
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