by Jim Bell
Still, Voyager 1 will continue to slowly travel northward and Voyager 2 southward, relative to the sun and the surrounding stars. Over time—enormous spans of time, as the gravity of passing stars and interacting galaxies jostles them as well as the stars in our galaxy—I imagine that the Voyagers will slowly rise out of the plane of our Milky Way, rising, rising, ever higher above the surrounding disk of stars and gas and dust, as they once rose above the plane of their home solar system. If our far-distant descendants remember them, then our patience, perseverance, and persistence could be rewarded with perspective when our species—whatever it has become—does, ultimately, follow after them. The Voyagers will be long dormant when we catch them, but they will once again make our spirits soar as we gaze upon these most ancient of human artifacts, and then turn around and look back. I have no idea if they’ll still call it a selfie then, but regardless of what it’s called, the view of our home galaxy, from the outside, will be glorious to behold.
My ASU colleague and Voyager historian Stephen Pyne has noted, poignantly, “Even as they are celebrated for racing forward—to the outer planets, to the heliopause, to interstellar space—many of their most dazzling discoveries were the offshoot of staring back at what they passed in their sling-shot fly-bys. Their trajectory is a triangulation of future and past, or what might be recalibrated as expectation and meditation. The Voyagers were special when they launched. They have become more so thanks to their longevity, the breadth of their discoveries, the cultural payload they carried, and the sheer audacity of their quest.”
“That’s the thing about this mission,” offered Ed Stone, reflecting on Voyager’s transition from a planetary to an interstellar mission, “there really hasn’t been an end. All of these encounters and events, are in some sense ‘ends,’ but they’re really not the end. That’s really the wonderful thing about Voyager.”
Postscript: NewSpace
HUMANS ARE CURRENTLY controlling about thirty different spacecraft that, together, make up an impressive robotic armada sent out to explore our solar system and beyond. At times we strain to see beyond the turmoil and the swift pace of modern life. We forget to take a moment to look outward and perceive our place in time. We are all living—right now—in an amazing Golden Age of Exploration, of our planet and of our solar system. And if we look closely, in our mind’s eye, we can see the Voyagers quietly ushering us to and across the threshold of the Interstellar Age.
How should the future of space exploration unfold? Will NASA and other government space agencies always lead the way? Will upstart private space-related companies (such as SpaceX, Virgin Galactic, Sierra Nevada, and dozens of others) dive into the robotic space-exploration game, and if so, why? For mineral resources? For fame and glory? To help protect the Earth from rogue asteroids or comets? To settle other worlds? Or will those companies instead focus mostly on providing services like lower-cost rocket launches, adventure-tourism experiences, space-station refueling/resupply, or satellite repair? Those questions are at the forefront of the emerging space industry sector often called NewSpace. Investors large and small are trying to predict which of these businesses, and which of these questions, will drive the future of space-related business and research. And perhaps unbeknown to most people, governments are playing important roles in the increasing privatization of space-related activities. NASA, for example, in their Commercial Orbital Transportation Services and other Commercial Crew & Cargo Programs, has doled out nearly $2.5 billion of taxpayer funding over the past five years or so to spur the development of many of these “private” initiatives. In many ways, the government is playing a similar role today in the creation of a privately run, civil space program that it played in the early to mid-twentieth century in civil aviation. In the 1920s, for example, the US government was the biggest and most reliable customer for the nascent airline industry, paying out sweet contracts for the delivery of airmail to then-upstart companies with names like TWA, Northwest, and United. Which private space companies being seeded by tax dollars today will emerge as household names and NewSpace industry giants of the twenty-first century?
While missions like Voyager were science- and exploration-driven, many NewSpace (and traditional “OldSpace”) companies are of course bottom-line- and profit-driven. Still, there is great potential for collaboration and cross-fertilization. By analogy, fruitful partnerships have emerged in recent decades between leading environmental and ecological preservation groups and organizations and some parts of the worldwide tourism industry. Nonspecialist individuals and families can now take vacations that also support scientific research projects related to the ecology, archaeology, sociology (and so on) of their destinations. I believe that a similar model could be highly effective for space-related tourism. What many space scientists want most for their research is access to the space environment—be it experiments in low gravity, or new measurements from orbital or landed/roving platforms—and an interested, excited audience (preferably decision makers at funding agencies, but really anyone genuinely interested is valued) with whom to share their results. If that access is provided by private NewSpace companies, and part of the price is that researchers have to be tour guides and teachers for the paying public sharing the ride, so be it. It’s a model that could work.
I like to imagine an entirely new branch of nerdy but potentially lucrative adventure tourism that could easily, in the not-too-distant future, be built around what I call “manufactured astronomical events.” We’ve all seen photos of the magnificent splendor of a total solar eclipse, for instance, but very few people have actually seen a total solar eclipse because they occur only about once every three hundred years in any particular city or region on Earth. But that’s because of the particular geometry of the sun, Earth, and moon for Earthbound observers. If we were to take a spaceship to the right places in space, it would be easy to fly the ship through the shadows of the Earth or the moon and re-create the same kind of eclipse experience for those aboard the ship. As another example, there was a lot of hubbub a few years back about people viewing the last transit of Venus across the disk of the sun until the year 2117. Not necessarily so! Take a ship full of astronomical adventure tourists to the right place in space and at the right time to watch, and—voilà!—there’s a Venus transit as good as any that you’d see from Earth. Many other kinds of “manufactured” celestial events will be possible to create once access to near-Earth (and lunar) space becomes more routine. We could experience Earth-and-moon solar eclipses, transits of Mercury or other planets, flights through active comet tails, flybys and landings on near-Earth asteroids, perhaps even visits to Voyager and other ancient spacecraft. Such excursions may never become as routine as airline travel is today, but I believe that the trend will surely be toward safer, more affordable, and more personally meaningful access to space for regular citizens.
Earth and Moon “Firsts” from Space. TOP LEFT: Lunar Orbiter I’s first whole Earth photo from space. TOP RIGHT: Apollo 8 color Earthrise photo from lunar orbit. BELOW: First image of the Earth and Moon together from Voyager 1.
Voyager and the Golden Record. TOP: Spacecraft and systems/instruments. LOWER LEFT: Close-up of the Golden Record case mounted on the side of the spacecraft bus. LOWER RIGHT: Close-up of the first side of the actual record.
Selections from the Voyager Golden Record. TOP LEFT: Golden Record Image 35: Father and child, showing a range of human forms and expressions. TOP RIGHT: Image 102: Rush hour in India, showing many aspects of human transportation. MIDDLE LEFT: Image 71: Stroboscopic photo of gymnast Cathy Rigby, showing the range of human motion over five seconds. MIDDLE RIGHT: Image 108: Stuck Sno-Cat from a 1958 Antarctic expedition, showing that we’re not perfect. BOTTOM LEFT: Image 74: Children examining a globe of Earth, with political boundaries. BOTTOM RIGHT: Image 114: Sunset on planet Earth.
Jupiter: Clouds and the Great Red Spot. Two spectacular examples of modern reprocessed Voyager images of Jupiter’s Great
Red Spot show the regional appearance of this three-Earth-sized storm system (TOP) and a close-up of just the storm itself (BOTTOM).
Europa, Close-up. One of the highest-resolution views of Europa obtained during the Voyager flybys, this reprocessed version of Voyager 2’s closest-approach mosaic shows spectacular examples of the cracks, grooves, and low ridges that imply the existence of a large subsurface ocean underneath this moon’s relatively flat, icy crust.
Voyager 2’s Departure from Saturn. About three days after the closest approach behind Saturn and the major scare from the scan platform anomaly, control was regained of Voyager 2’s cameras, resulting in breathtaking, impossible-from-Earth photos like this from beneath the plane of the rings. Modern digital reprocessing of the data helps to bring out additional subtle details in color and structure.
Jumbled Miranda. The highest-resolution images from Voyager 2’s flyby of the Uranian moon, Miranda, were digitally reprocessed into this new mosaic of the smallest, and most bizarre, body-orbiting seventh planet. Planetary scientists still don’t understand how such abruptly different kinds of terrain could end up all jumbled together like this.
Neptune, Triton, and the Rings. Voyager 2 wide-angle and narrow-angle views of Neptune, its faint ring system, its large moon Triton, and simulated views of the background stars at the time of Voyager 2’s flyby, were combined in this digitally-reprocessed mosaic depicting the last port of call for the mission.
Voyager 2 Color Mosaic of Neptune’s Large Moon Triton. The blueish-green “cantaloupe” terrain at center and top of this view consists of ridges and plains of nitrogen ice, while the pinkish, mottled region at the bottom is thought to be a polar cap made mostly of methane ice. Black streaks in the polar cap mark the locations of the geysers detected by Voyager scientists.
A Simplified Model of the Heliosphere. The sun is at the center of this cartoon model of the “bubble” of solar magnetic field lines (black, radiating out from the sun) and solar wind particles (colored green to red based on their temperatures). The bubble is interacting with interstellar magnetic field lines (black, coming in from right to left) and interstellar particles (colored blue to teal based on their cooler temperatures). The paths of Voyager 1 and Voyager 2 as of early 2014 are also shown. The boundary between the green and teal regions is the heliopause, which Voyager 1 crossed in 2012 and Voyager 2 is predicted to cross soon.
Notes and Further Reading
Direct quotes in the book come from a series of interviews that I conducted during 2013 and early 2014 with many Voyager friends and colleagues that I’ve had the privilege of talking with and/or working with. I recorded and transcribed the interviews, and confirmed the use of the quotes with each interviewee. I have listed these folks among the Acknowledgments because I am truly grateful for their time and patience!
Chapter 1. Voyagers
the privilege of walking on another world: To be the hit of the party sometime (at least, the kinds of parties I go to . . .), memorize and then recite all twelve of their names! In order of their missions (Apollos 11–12, 14–17): Neil Armstrong and Edwin “Buzz” Aldrin; Pete Conrad and Alan Bean; Alan Shepard and Edgar Mitchell; James Irwin and David Scott; Charles Duke and John Young; and Harrison “Jack” Schmitt and Gene Cernan.
so cute with their long necks and bulging eyes!: Does “cuteness” matter in space exploration? See planetary scientist Melissa Rice’s thoughts on the topic in her Planetary Society blog entry “In Memory of Spirit, and Why Cuteness Matters” at planetary.org/blogs/guest-blogs/3065.html.
largest public-membership space-advocacy organization: You can learn more about the history and vision of The Planetary Society at planetary.org. I can’t help but sing the accolades of this merry band of fellow space explorers, as I happen to be the society’s president!
some in Congress have asked (really): For an example, see NASA historian Stephen J. Garber’s article “Searching for Good Science: The Cancellation of NASA’s SETI Program,” Journal of British Interplanetary Society 52 (1999): 3–12 (online at history.nasa.gov/garber.pdf).
Why should American taxpayers support NASA?: Wikipedia has a fairly comprehensive entry on the history of the NASA budget, with links to more information, at en.wikipedia.org/wiki/Budget_of_NASA.
inspiration is priceless during tough times: Watch and read Neil deGrasse Tyson’s passionate 2012 testimony to the US Senate’s Commerce, Science, and Transportation Committee on Neil’s own website, at haydenplanetarium.org/tyson/read/2012/03/07/past-present-and-future-of-nasa-us-senate-testimony.
complications of a stroke, passed away in late 2005: A nice “In Memoriam” piece written by several of Ed Danielson’s professional colleagues can be found in the planetary science journal Icarus 194 (2008): 399–400 (online at dx.doi.org/10.1016/j.icarus.2007.12.007).
Chapter 2. Gravity Assist
“the basic ideas behind gravity assist . . .”: David W. Swift, Voyager Tales: Personal Views of the Grand Tour (Reston, VA: American Institute of Aeronautics and Astronautics, 1997), page 63.
pass each planet with the shortest possible trip time: Ibid., page 64.
The next opportunity would not appear: Ibid.
“Many openly scoffed at the idea,”: Ibid., page 66.
“Many myths have arisen . . .”: Ibid., page 69.
“Those at JPL who brought everything together . . .”: Ibid.
then two in 1979 to fly by Jupiter, Uranus, and Neptune: 1970 Annual Report, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, page 8 (online at http://www.jpl.nasa.gov/report/1970.pdf).
“They told us, ‘If you guys . . .”: Douglas Smith, “The Other Side,” Engineering & Science Magazine, California Institute of Technology, Pasadena, CA, Winter 2013, 10–13.
built around a basic chassis called a bus: Dave Doody, Deep Space Craft: An Overview of Interplanetary Flight (New York: Springer/Praxis, 2009), page 143.
significantly changed from the original Mariner configuration: Andrew J. Butrica, “Voyager: The Grand Tour of Big Science,” in From Engineering Science to Big Science, ed. Pamela E. Mack, NASA History Office Special Publication 4219 (Washington, DC: National Aeronautics and Space Administration, 1998), 251–76 (online at history.nasa.gov/SP-4219/Contents.html).
complete the Great Pyramid at Giza for King Cheops: C. Kohlhase, ed., The Voyager Neptune Travel Guide, JPL Publication 89-24 (Pasadena, CA: Jet Propulsion Laboratory, California Institute of Technology, 1989), page 135 (online at babel.hathitrust.org/cgi/pt?id=uiug.3011205 6430637).
Chapter 3. Message in a Bottle
“We step out of our Solar System into the universe . . .”: Carl Sagan, F. D. Drake, Ann Druyan, Timothy Ferris, Jon Lomberg, and Linda Salzman Sagan, Murmurs of Earth: The Voyager Interstellar Record (New York: Random House, 1978), page 26. See also an online index of the “Scenes from Earth” photo collection at voyager.jpl.nasa.gov/spacecraft/scenes.html and an online index of the “Music of Earth” music collection at voyager.jpl.nasa.gov/spacecraft/music.html.
cast out forever into interstellar space: For details on the origin and content of the Pioneer plaques, see Carl Sagan, Linda Salzman Sagan, and Frank Drake, “A Message from Earth,” Science 175, no. 4024 (1972): 881–84 (online at sciencemag.org/content/175/4024/881.short).
“carry some indication of the locale . . .”: Ibid., page 881.
“Pioneer 10 and any etched metal . . .”: Ibid.
“the message can be improved . . .”: Ibid., page 883.
“If we don’t send things we passionately care for . . .”: Sagan et al., Murmurs of Earth, page 254.
“Hello to everyone . . .”: Ibid., page 143.
a variety of nearby stars in 1999 and 2003: The “Cosmic Call” refers to two sets of messages sent to nearby stars from the RT-70 radio telescope facility in Yevpatoria, Crimea, in 1999 and 2003. See en.wikipedia.org/wiki/Cosmic_Call for more details.
“which didn’t turn out very well . . .”: Stephen Hawking, Into the Universe with Stephen Hawking, Television Series, Episode 1: “Aliens,” Discovery Channel, 2010.
Martian sundials: Woody Sullivan and Jim Bell, “The MarsDial: A Sundial for the Red Planet,” The Planetary Report (January/February 2004): 6–11.
“It’s wise to try . . .”: Michael D. Lemonick, “Life beyond Earth,” National Geographic, July 2014, page 44.
Photos and Diagrams on the Voyager Golden Record: Sagan et al., Murmurs of Earth, pages 71–122.
Music on the Voyager Golden Record: Ibid., pages 161–209.
140 countries signed online petitions: Jon Lomberg’s “One Earth: New Horizons Message Project” website can be found at oneearthmes sage.org.
the One Earth: New Horizons Message Project: Ibid.
Chapter 4. New Worlds among the King’s Court
the right amount to swing the probe on to Saturn: Charley Kohlhase’s ongoing memoirs, “The Complete Rocket Scientist,” which includes fascinating technical details about how he and the Voyager team designed the Jupiter-Saturn-Titan and Jupiter-Saturn-Uranus-Neptune trajectories of Voyagers 1 and 2, is online at charleysorbit.com/completerocketscientist/lifebook1.php.
the equivalent of about 1 foot per trillion years: Kohlhase, Voyager Neptune, page 139.
what those in the business call a 3-axis stabilized spacecraft: For all kinds of wonderful detail, diagrams, and descriptions of Voyager’s many spacecraft systems and instruments, see “The Voyager Spacecraft,” by former project manager Raymond L. Heacock, published in the Proceedings of the Institution of Mechanical Engineers 194, no. 28 (1980): 211–24 (online at stickings90.webspace.virginmedia.com/voyager.pdf).
