The Voyager mission consists of two identical automated space laboratories designed to study Jupiter, Saturn, and Uranus. To the scientists and engineers who have given years to this mission, however, the spacecraft are more than just robot laboratories. The Voyager twins are their children, born of their imagination and intense curiosity about the mysteries of the solar system.
I recently talked with two colleagues of mine who have been involved with the Voyager mission since the planning stages: Dr. Hal Mazursky, a member of the Voyager imaging team and an investigator on many interplanetary missions, and Dr. Lonnie Lane, the principal investigator for the Voyager photo-polarimeter experiment and deputy project scientist for the Voyager-Jupiter encounter. We discussed the human side of a mission like Voyager, what emotions and feelings underlie their basic scientific curiosity, and what lures a scientist to invest himself in this kind of a project.
Apart from your natural curiosity as scientists, what do you feel like as human beings involved with the mission as Voyager 1 approaches Saturn?
[Mazursky]: There is enormous anticipation, because you've been heavily involved with the whole making of the concept as well as working with the [ mission] operations . . . and when you see the results, then it's much more exciting than watching things that have come down that are the product of other people's work. . . . I myself very much enjoy actually working with the data as it's coming in, and responding to it and suggesting changes. It makes it an interactive thing rather than something devised years before which finally comes back sort of by itself.
[Lane]: There is a tremendous feeling of exhilaration . . . There are analogies one can draw, like a baseball player hitting a pinch-hit grand-slam home run when his team is down by three runs in the bottom of the ninth inning. It's that kind of a feeling . . . of total performance against odds that are astronomically large. . . .
Think back to a little over a year and a half ago, when Voyager 1 encountered Jupiter. What went through you when you first saw the Io "pizza" picture [the sulfurous red and yellow surface of one of the major moons]?
[Mazursky]: I think that one of the peculiar pleasures of working with spaceflight projects is that there's such an intimate intermix between the emotional involvement with new discoveries and the scientific appreciation. And to me that's really a very intense experience. . . . The nice thing about it is that so often we've been wrong in our anticipation of what we are going to see. So often we've looked at bodies that are totally different from anything we've ever seen before.
What major surprises do you think we're going to find when Voyager gets to Saturn?
[Mazursky]: The fascinating thing about the Jupiter system was the incredible variability in the several planetary bodies [Jupiter plus its moons]. It had such a powerful effect when we saw, just within this small group, so many extremes. What I anticipate on Saturn is that our record will be less complete. It may be less dynamic, but hopefully we'll get glimpses of other things that might go on. We may see ices, but hopefully ices of more complex composition. And, hopefully, the geological processes interacting with those [ices] will be revelations of a new kind.
[Lane]: We've stood back from Saturn for 300 years looking at the rings, and they've always been, in pictures, relatively uniform, with some hints of little things in them. I think we're going to find that the ring structure is very much different up close than we could have ever imagined. Unlike Jupiter, Saturn's atmosphere has appeared very bland. I'm hoping that when we get some good multicolored imaging we'll be able to finally see some atmospheric structure that would reveal waves and things going on. With the satellites, I think we'll end up with some surprises. We've always guessed that satellites such as Rhea were nice icy things. Titan has got its atmosphere.You don't know how much or how deep. I think the surprises are going to come when we try to put it all together, and find, sort of like we found on Jupiter, large class distinctions in the satellites as we go around the Saturn system.
What about the possibility of life in the Saturn system?
[Mazursky]: I'm interested in the life question because geology is, after all , history. And the life processes are an enormously significant part of our understanding of the history of the solar system, so that you're continually aware of this interplay between the physical surroundings and the creative life processes. On Mars, I didn't really think we were going to discover life. But it didn't decrease my pleasure in the results, because I have an intense awareness of the evolution of planetary bodies as being something not that different from the evolution of the life principle. Looking at volcanic action and water action and wind action and their complex interplay on Mars was a very intriguing prospect. It would have been even nicer if we had the added complication of life. But it still made it a very complicated and satisfying story.
[Lane]: The question of life is always there, but I think that with the particular collection of investigators and personalities that the Voyager program has, it's oriented more toward physical discovery than biological discovery. I think that's more the bent of the people, unlike the Viking lander team, whose members were really tied into that question of life very crucially.
With Voyager, considering the distances we are from things and the kind of instrumentation we have on board, we can only answer some of the simplest aspects of the three crucial life-related questions: Is there chemical composition, is there temperature, is there a physical state out there which is benign to the kind of life we know. I think our biggest surprise would be finding a physical state that is not benign to our life, and yet having an indication that there is a level of organization that does not happen in nature under random processes. A life force of some sort.
Maybe I'm starting to talk like "Star Wars," but that I think would be the biggest surprise. And if you had to ask the Voyager investigators about it -- given the environment that's out there, with the ammonia, with the methane, with the low temperatures, and all these things that are relatively inhospitable to us as Earth-bound humans -- the question that may exist at a low level in each of them is: Is there a collection of states out there that leads to some other "something," which is very happy in that domain, and which obviously is not just a raw chemical or physical phenomenon? The Voyager investigators carry that hope , they look carefully, they're very analytical about the way they approach it. But I think that within each of them -- and they are still people -- this is an interest they share with all people.
We can carry Lonnie Lane's last comment a bit further. Human beings, by nature, are explorers. This is a fundamental force in each of us. We have always been this way in the past, and we will continue to reach out toward the unknown for as long as we survive as a species. Voyager is simply a natural step in a process that is aeons old. Although Voyager was designed and built by a small group of highly trained individuals, in actuality there is a part of each of us in those spacecraft. On Nov. 12 we all can each share the with Voyager team the excitement of discovery, searching for new worlds and new ideas hundreds of millions of miles from home.