The Voyager Spacecraft — Humanity’s Calling Card — A Real Star Trek Adventure, Still Boldly Going Where No One/Probe Has Gone Before; Voyager I Set To Leave Our Solar System
While the eclipse this week dominated the science world, and rightfully so, there is another magnificent event involving the cosmos; and that is the wonderful saga of the Voyager I and Voyager II space probes. Dennis Overbye, who is a writer specializing in physics and cosmology, had a fascinating article in the August 22, 2017 edition of the New York Times, “The Voyagers, Humanity’s Calling Cards,” about two space probes that are on the verge of leaving our solar system and beyond — an onto the great unknown.
“It was forty years ago, August 20, and September 5, 1977, that a pair of robots named Voyager I and Voyager II, were dispatched to explore the outer solar system and the vast darkness beyond,” Mr. Overbye wrote. “It was,” he writes, “a real-life, Star Trek adventure, but the crew stayed home, communicating with their two spacecraft through a billion-mile bucket brigade of data bits. New computer programs went one way, and data — including scratchy photos of new landscapes, and the whispering moans of interplanetary plasma fields — came back the other way. All of it was being carried out by a robot brain with the memory capacity of an old-fashioned digital watch.”
Richard Hollingham, writing in the August 18, 2017 edition of the BBC.com, noted that “Voyager I left [our] the solar system; and at the time of the writing of this article [his article on August 18], is 20 billion kilometers/12 billion miles away. Voyager II, on a different trajectory, is 17 billion kilometers/10.5 billion miles away.” He adds, “the signals are received by NASA’s deep space network — [a series of] giant satellite dishes scattered around the world, designed to pick up data from distant spacecraft. As I watch [Mr. Hollingham] Duty Mission Controller Enrique Medina calls-up a ground station near Canberra, Australia, to establish contact with Voyager II. The spacecraft are so far away,” Mr. Hollingham adds, “engineers need to line up two receivers to capture the signal from the edge of the solar system. It takes a radio signal traveling at the speed of light 38 hours to travel from Earth to Voyager I and back; and, some 30 hours for Voyager II.”
“The power of the transmitter on the spacecraft is around 12 watts,” Medina said. “When it’s on high power — it’s 20 watts, around the same [power] as a light-bulb on a fridge.” “It never ceases to amaze me,” Medina said. “This is 1970s technology we’re talking about.”
“The spacecraft had been designed to make what scientists called the Grand Tour, taking advantage of a once-every-175 year planetary alignment,” Mr. Overbye noted. “Voyager I and Voyager II, were to use the gravity of the outer planets, to slingshot from Jupiter to Saturn, and to Uranus and Neptune, and then beyond the edge of the sun’s domain — and into interstellar space.” Alas, Voyagers cameras have been turned off, Mr. Overbye notes, as the Voyager team here on Earth conserve the probes’ energy for exchange of communication and data.
“In November 1980, Voyager I left Saturn behind to begin its long journey out of the [our] solar system; and crossed the boundary between the space dominated by the Sun’s magnetic field, and, the space between the stars,” Mr. Hollingham observed. “Nine months later, Voyager II set course for the outermost planets. It reached Uranus in 1996, snapping the first pictures of the gas giant, its rings, and also discovered 10 new moons.” “The Sun creates this huge bubble around the planets,” said Ed Stone, “a legend among space scientists,” Mr. Hollingham writes. “Now in his 80s, Stone has been leading the Voyager mission at the Jet Propulsion Laboratory (JPL) in Pasadena, California since Voyagers design and construction in 1972.” “This is a partial shield from the cosmic rays outside — we’re now learning how our bubble interacts with the material from other stars.”
“Voyager I continues to collect information about the void; and, in the coming years, Voyager II will also pass beyond the [our] Solar System,” Mr. Hollingham wrote. “Because it’s leaving at a different angle to its twin, the data Voyager II gathers will give scientists insight into the shape [and size?] of the solar bubble,” beyond the Sun and at the outer edge of our solar system.
“But, time is running out,” Mr. Hollingham notes. “The spacecraft are powered by nuclear batteries, with electricity generated from heat produced by the decay of plutonium. Every year, four watts less heat is produced.” “The objective is to keep them flying as long as possible,” said Voyager Program Manager Suzy Dodd. “You can imagine them being twins, and over the course of nearly forty years, one has lost hearing, and the other doesn’t see so well, so we have to be very careful. We’ve been running off redundant systems. We only operate the instruments that can take data where the spacecraft are — we don’t operate the cameras anymore because there’s nothing to see — it’s just very, very, dark space.”
“One day — probably in the next ten years, Dodd knows that Voyager I and II will have to be shut down — it’ll be like losing a grandparent, or a close relative who’s lived a full and very rewarding life,” she said. “One day, we’ll be looking for a signal from Voyager, and we won’t get it.”
“In a way, however, the Voyager mission will last forever,” Mr. Hollingham wrote. “Probably longer than human civilization.” “I would like to think that sometime in the [distant] future, something, or somebody will find them, play the golden record, and look at what by that time, will be an ancient civilization,” Dodd said. “Our Earth may be long gone by the time that golden record is found.”
“The Voyagers will become our silent ambassadors in the Milky Way,” Stone said. “They will be in orbit around the center of the galaxy for billions of years.” “But, he’s not as optimistic as Dodd that the Voyagers will ever be discovered,” Mr. Hollingham wrote. “It’s be remarkable — space is really empty.”
“In the fullness of galactic time,” Mr. Overbye concluded his article: “The Voyagers may be found; but by then,” he says, “the human race may be long extinct. The Voyager record may be the only physical remains of the last lonely evidence, that we too, once lived in this city of stars, among these islands of ice and rock.”
Very fascinating. As the late Sci-Fi author/legend Arthur C. Clark once said, “We are either all alone in the universe…..or, we aren’t. And either of those two outcomes is frightening.”
If you would like to read more on the Voyager mission/s, I refer you to Jim Bell’s comprehensive and engrossing, “The Interstellar Age: Inside The Forty-Year Voyager Mission, published in 2015 by Dutton. Howard Schneider wrote in a February 20, 2015 article/book review (Wall Street Journal) of Mr. Bell’s book that “In 2013, NASA scientists announced that, in August of the previous year, Voyager 1 had passed beyond the limit of the solar wind; in effect, it left our solar system. though not all scientists agree,” that the probe actually left our solar system. “In any case,” he added, “Voyager 2 will join the other spaceship one day in interstellar space. The probes should have enough power to allow them to communicate with Earth and operate at least one instrument each until about 2025. After that, the NASA team hopes that the craft can still somehow remain in touch with their home planet, but it’s all theory at this point.”
“Why is unmanned space exploration important?” Mr. Schneider asks. “The implicit answer in “The Interstellar Age,” is that it makes us smarter, which is a splendid achievement. In the prelude to this book, Mr. Bell writes: “Via technology, their [the Voyagers’] discoveries and the messages that they are delivering to the galaxy on our behalf, [means] we have all entered the Interstellar Age. This may be the ultimate legacy of the men and women, and machines of Voyager.” Makes one proud to be an Earthling,” Mr. Schneider concludes. Amen.
Mankind has an insatiable curiosity, that can only be satiated by breaking through barriers, and ‘going, where no ‘man’ has gone before.’ What lies beyond our solar system?, how many other universes are out there?, are we all alone?, why are we the anomaly? What is our ultimate purpose? Where will we be in a 1,000 years? 1 million years? 1 billion years? The Voyagers don’t even constitute a baby step down that road; but, it is a beginning, and hats off to Dr. Stone and all those who made the Voyager mission/s possible. V/R, RCP, www.fortunascorner.com