The Interstellar Age (2 page)

Voyager 1
and
2
Trajectories.
Schematic diagram of the trajectories that enabled NASA’s twin
Voyager
spacecraft to tour the four gas giant planets and achieve the velocity to escape our solar system.
(NASA/JPL)

The twelve-year-old me had become hopelessly hooked on space exploration watching the adventures of the
Apollo
astronauts on the moon. My parents tell me that they woke me up on that Sunday night in July of 1969 to witness Neil Armstrong and Buzz Aldrin make history on live TV in the Sea of Tranquility. We saved the
Monday
MAN ON MOON!
giant headlined copy of the Providence
Evening Bulletin
, which I later had framed. For the next three and a half years, I was glued to the television, whenever possible, watching these guys walking—and
driving cars!
—on the lunar surface. While I was assured by the voices of NASA engineers and space commentators that it was hard work, many of the astronauts seemed like they were having fun. I want to do
that
, I thought. I dressed as an astronaut for a long run of Halloweens.

I followed the exploits of the twin
Viking
landers sent to the surface of Mars in 1976. Even though people weren’t going, the idea of sending two car-sized robots on a 150-million-mile remote-control
journey and getting them to set down, softly, onto the surface of the Red Planet was astounding. In the decades ahead I would witness firsthand even crazier Mars landing systems as the
Mars Pathfinder
and
Spirit
and
Opportunity
rover mission set down on Mars—successfully—using bouncing airbags, and the larger
Curiosity
rover did so using its Rube Goldberg–like “sky crane” landing system.
Viking
used old-school technology, like parachutes and retro-rockets, right out of a Bugs Bunny cartoon. While Marvin the Martian wasn’t waiting there for us, the Mars that was revealed by the
Vikings
turned out to be eerily like deserts on Earth, though much dustier, colder, and drier.

The early 1970s-era cameras on
Viking
were essentially faxing their photos back to Earth, and NASA was using what was then brand-new electronic imaging technology that needed no photographic film. Instead, it converted the sunlight reflected off of a Martian scene into radio signals, beaming them back to Earth, where the faint signals were picked up by radio telescopes the size of a baseball field. I saw the digital images these faint signals produced revealed on the nightly news. The first images came down live, and painstakingly slow—one column of picture elements or “pixels” at a time. Space photography! I want to do
that
, too, I thought. My parents and grandparents helped me buy a telescope and some attachments to link it up to my 35mm camera.

These days it’s hard to explain to my kids, or to my students, what it was like growing up thirsty for science in the 1970s and 1980s. Imagine a world, I implore them, where there are only three major TV networks plus another run by the government, called the Public Broadcasting Service, or PBS. Imagine further that for the most part only the government channel would have science shows
on TV (not counting
Star Trek
—one of my favorites, to be sure, but only partly “science”). For the most part, science TV was dominated at the time by
NOVA
—the educational and beautifully produced show from Boston’s WGBH station that is still running strong today. But that was basically it: no Science Channel, Discovery Channel, National Geographic Channel, NASA TV, History Channel, or for that matter, no Fox, CNN, MTV, VCRs, DVRs, and
no way to skip the commercials.
They look at me in horror, as if I had to endure being raised by wolves in the frozen tundra. Then they shoot me a truly pitiful look when I remind them that, worse yet, we had no Internet. Gads! How did we survive?!

In that bleak landscape of science communication was the TV show
Cosmos
, which first aired on PBS in 1980. The show’s host, the astronomer, planetary scientist, astrobiologist,
Voyager
imaging team member, and science popularizer Carl Sagan, was probably the first scientist I had ever encountered who spoke English. I mean common English, more like what you’d hear around the dinner table than the jargon and shorthand codes that most scientists typically use when talking about their work. But that plain talk was also laced with metaphor and analogy and evocatively grand cadences, often accompanied by the soaring and romantic electronic music of Vangelis. Sagan revealed the mysteries of the planets and moons and asteroids and comets and stars and galaxies and where we came from and where we’re going. I found myself
listening to him
and falling in love with the idea of doing science, of possibly even becoming a scientist. It was a captivating, mind-blowing, entertaining glimpse into the modern world of astronomy and space exploration. I would eagerly await each week’s new episode, talking about it endlessly the next day with my nerd friends at school, mimicking Sagan’s distinct,
guttural staccato voice . . . “Perhaps, one day, we will sail among the stars on gossamer beams of light. . . .” My mother loved his turtleneck and tweed jacket (I would get to introduce her to him many years later, at a professional conference we both attended in Rhode Island. We were both just starstruck, but Carl was kind, warm, and thoroughly approachable).

Back in 1977, it was clear to even a teenager that
Voyager
would be something very different from
Viking
. First of all, it would embark on a long journey. It would sail on for more than a decade at least, and if nothing bad happened along the way, the plutonium-fueled nuclear power pack that generated electricity for the spacecraft could keep the systems working for perhaps
fifty years
. With that kind of longevity, it was possible for the spacecraft to survive long enough to cross into interstellar space—the realm outside of our sun’s protective magnetic cocoon.
Voyager
would then venture out into the strange and unfamiliar interstellar wind. Wild. And second, the mission had the potential to literally discover entirely new and alien worlds!
Viking
had made important discoveries on Mars, but the landscape and processes had generally been familiar: wind, sand, maybe a little water long ago, grinding down and carving into the rock, eroding landscapes like you might encounter on a car trip through northern Arizona, Utah, and southern Colorado.
Voyager
would be encountering worlds not of rock, but of ice and gas, places where the sun is only the blip of a flashlight in an otherwise black, starry sky, and where the temperature might be only a few tens of degrees above absolute zero.

Through my youthful eyes, the biggest appeal of
Voyager
was indeed this idea of exploring the truly unknown—throwing a bottle, of sorts, into the cosmic ocean and seeing where the eddies and
currents of nature would take it. In my telescope, on a clear cold night, I could make out the reddish-brown belts and bands of Jupiter, as well as its famous Great Red Spot. It was a good-sized instrument for a young amateur astronomer, a so-called Newtonian telescope (designed by Isaac Newton, and using mirrors instead of lenses) made by a company called Meade Instruments, with a main mirror about eight inches in diameter and a tube about four feet long. With that tube held by a metal mounting post and three wide metal legs, it was a heavy, bulky, cumbersome thing to schlep outside and in from the garage and to set up every time I wanted to use it (especially in the snow), but it was so worth the effort. I could resolve the enchanting, creamy yellow rings of Saturn and learned firsthand why that planet was called “the jewel of the solar system” by the pioneers of astronomy. It always amazed me, in fact, that when I looked at Saturn I was seeing
the real Saturn.
Like a lot of kids at the time, I collected coins and stamps and baseball cards, and that was great, but there was always someone with an older, better, or cooler collection than mine. No one had a
better Saturn
in their planet collection—I was looking right at the real thing with my own eyes. I felt an unfamiliar sensation, an extraordinary lightness, as I took in the nearness of a world so distant.

In my small telescope, Uranus and Neptune, and the six or seven little moons I could sometimes find perched around Jupiter and Saturn, were just specks of light. It was hard to imagine these dots as worlds, as destinations one might visit, as lands of rock and ice, wind and volcanoes, polar caps, and panoramas so staggeringly familiar and yet patently alien. They were just dots, to me and everyone else on our little blue planet—even the largest telescopes in the world at the time couldn’t reveal their true nature. But I knew that
Voyager
would change that, that these dots would soon permanently become distinct places, as diverse in character as the myriad environments of our own planet, and far more exotic than our own moon (which had also, only recently, become a bona fide place, rather than a two-dimensional icon in the sky). The ability to ride along with
Voyager
, to be a passenger on this trailblazing journey destined to discover entirely new worlds, to
see history made
, was irresistible to the young me. In fact, it still is.

EXPEDITION LEADERS

Famous ships of exploration are usually led by a famous captain or commander, like Christopher Columbus, Ferdinand Magellan, James Cook, Ernest Shackleton, or Neil Armstrong. The
Voyagers
, however, are led by a committee of captains—managers, engineers, and scientists from NASA’s Jet Propulsion Laboratory (JPL) and elsewhere who were tasked with overseeing the design, manufacture, and operation of the most ambitious robotic planetary exploration mission yet attempted—and a pair of equally powerful commanders, a project manager and a project scientist.

In NASA and JPL parlance,
Voyager
is a “Project” (capital
P
), run by a Project Office (capital
O
) and divided organizationally into a number of subsidiary offices. These include the Mission Planning Office, where the detailed spacecraft trajectories were designed; the Flight Science Office, which includes the science team and which is responsible for making sure the mission achieves its scientific objectives; the Flight Engineering Office, with the engineers and managers
who designed and built
Voyager
’s power, thermal control, communications, and propulsion modules; the Flight Operations Office, which provides the procedures and software needed to plan and actually operate the spacecraft and its science instruments (and which includes two teams of JPL scientists and engineers: the spacecraft operations team, who directly communicate with the spacecraft and who monitor its status and health over time, and the science support team, who serve as the interface between the science team and spacecraft operations team); and the Ground Data Systems Office, which provides the hardware and software needed to send commands up to the spacecraft (“uplink”) as well as to receive and process data back down from the spacecraft (“downlink”).

The project manager leads the Project Office and is the engineering and management commander of
Voyager
, responsible for getting the spacecraft built and tested, keeping the mission safely operating on time and on budget, and overseeing the hundreds of contractors and several thousand engineers, technicians, and other managers on the Project. The project scientist runs the Flight Science Office and the science team—a group of scientists, engineers, technicians, managers, and students from around the world who designed, built, and operate the science instruments and who interpret the downlinked data. The project scientist is the scientific commander of
Voyager
, responsible for making sure the mission achieves its science goals on time and on budget and for coordinating and herding (like cats) the hundreds of scientists on the Project.

Each
Voyager
carries scientific instruments for eleven investigations. These include wide-angle and high-resolution cameras for imaging and spacecraft navigation; radio systems for studying
gravitational fields and planetary radio emissions; infrared and ultraviolet spectrometers to measure chemical compositions; a polarization sensor for surface, atmosphere, and planetary ring composition; a magnetometer measuring magnetic fields; and four devices for studying charged particles, cosmic rays, plasma (hot ionized gases), and plasma waves. Scientists conducting each investigation are organized into instrument teams, and the leader of each instrument team is called the principal investigator (or PI). The PIs are responsible for the design, construction, and operation of each of their instruments, and together they form the Science Steering Group, which is chaired by the project scientist and which reports to the project manager.

In this kind of committee-led project, it’s critical that the two commanders at the top of the org chart, the project manager and the project scientist, are consistently on the same page and have an excellent working relationship. Each is personally responsible for the success of the mission—to NASA and, ultimately, to Congress and the taxpayers who are footing the bill. Over the course of more than four decades since the Project began,
Voyager
has had ten project managers. But during that entire time, the mission has had
only one
project scientist: Edward C. Stone.

Ed Stone is a space weatherman, a physicist who studies the ways that high-energy particles called cosmic rays travel through space and interact with the magnetic fields and atmospheres of the sun and planets. Cosmic rays are a form of high-energy radiation made of protons and the nuclei of atoms, and they travel through the universe at nearly the speed of light. Exactly where they come from is still a mystery—they could be caused by massive supernova explosions of dying stars, or by the powerful black holes in the centers
of active galaxies, for example. Regardless of how they formed, scientists like Ed can use the properties of cosmic rays to understand the details of the ebb and flow of the solar wind (the stream of high-energy particles coming off the sun) and the way that wind is carried by the sun’s magnetic field and interacts with the magnetic fields of the planets. Measurements of this kind of “space weather” were some of the first scientific measurements ever made from space satellites, and Ed Stone has been a prolific scientist in this game since the beginning.