The Interstellar Age (38 page)

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).

a team of three celestial mechanics experts
:
S. J. Peale, P. Cassen, and R. T. Reynolds, “Melting of Io by Tidal Dissipation,”
Science
203, no. 4383 (1979): 892–94 (online at http://dx.doi.org/doi:10.1126/science.203.4383.892).

“
Voyager
images of Io may reveal . . .”
:
Ibid., page 894.

the Io images taken for navigation purposes
:
The “discovery photo” where Linda Morabito and colleagues first noticed the volcanic plumes of Io is online at photojournal.jpl.nasa.gov/catalog/PIA00379.

were eruption plumes from active volcanoes on Io
:
For a full, detailed, first-person account of the events leading up to the historic discovery of Io’s active volcanic plumes, see Linda Morabito,
Discovery of Volcanic Activity on Io
, archived online at arxiv.org/pdf/1211.2554; for more stories and details about the study and discovery of volcanoes on other worlds since then, see also Rosaly Lopes and Tracy Gregg, eds.,
Volcanic Worlds: Exploring the Solar System’s Volcanoes
(New York: Springer-Praxis Books, 2004).

I can live to see that exploration pay off
:
For a great update on the status of the search for life in extreme environments like Europa, as well as upcoming plans for Europa exploration, see Michael D. Lemonick’s “Life beyond Earth” in the July 2014 issue of
National Geographic
magazine.

“By far the simplest explanation . . .”
:
Lorenz Roth’s December 2013 press release describing the Hubble Space Telescope’s potential discovery of plumes of water vapor coming from Europa can be found online at http://www.nasa.gov/content/goddard/hubble-europa-water-vapor.

“Decadal Survey of Planetary Science”
:
The recent 2011 National Academy of Sciences Decadal Survey of Planetary Science,
Visions and Voyages for Planetary Science in the Decade 2013–2022
can be found online from the National Academies Press at nap.edu/openbook.php?record_id=13117.

Chapter 5. Drama within the Rings

inner and outer parts orbiting at different speeds
:
For a fascinating and entertaining account of Maxwell’s work on Saturn’s rings, as well as his fundamental contributions to the physics of electricity and magnetism, see Basil Mahon,
The Man Who Changed Everything: The Life of James Clerk Maxwell
(Hoboken, NJ: Wiley, 2003).

perspectives to come from the
Voyagers
that would follow
:
Amateur astronomer and planetary image processor Ted Stryk has compiled a nice collection of
Pioneer 11
“greatest hits” images of Saturn online at strykfoto.org/pioneersaturn.htm.

perhaps some other complex hydrocarbons
:
This and other early pioneering planetary spectroscopic discoveries were made by the Dutch-American astronomer Gerard P. Kuiper, who is widely regarded as one of the founding fathers of modern planetary science. There’s a nice Wikipedia biography of Kuiper online at en.wikipedia.org/wiki/Gerard_Kuiper.

could have led to the formation of life on Earth
:
Wikipedia’s entry on the Miller-Urey experiments at en.wikipedia.org/wiki/Miller-Urey_experiment is a great starting point for learning more about these famous early efforts at understanding the possible origins of life on Earth and other habitable worlds.

Voyager
’s cameras were blind to the surface itself
:
Uncovering those secrets, including discovering the hoped-for seas of ethane and methane, would have to wait more than twenty-five years, when the
Cassini
Saturn orbiter, armed with cloud-penetrating radar inspired by
Voyager
’s discoveries, would finally map the fascinating geology and hydrology of Titan and when the ESA
Huygens
probe would get near-surface images just before landing. My planetary science colleagues Ralph Lorenz and Christophe Sotin wrote an exciting and accessible article about our current knowledge of enigmatic Titan, “The Moon That Would Be a Planet,” in the March 2010 issue of
Scientific American
magazine.