September 5, 1977 NASA launched the Voyager 1 probe, on a mission to orbit Jupiter and Saturn and send back photos and scientific data. Because the probe is built like a tank and nuclear-powered, they hoped it would survive the initial mission parameters and gave it long-term instructions… to eventually exit the solar system.
Thirty-five years later, Voyager 1 is still flying, still sending back data (although the cameras were shut down twenty years ago), and is now poised at the heliopause of our solar system, ready to take that next historic step. With its twin, Voyager 2, it is the longest-operating spacecraft in history and at 11 and 9 billions of miles, respectively, from Earth, the most distant.
If that isn’t mind-boggling enough, consider this: they each have only 68 kilobytes of computer memory. For those not up on their metric system, that is 68,000 bytes of memory. The laptop I’m writing this on has 4 gigabytes: 4,000,000,000 bytes of RAM. Oh, and for data recording, they have 8-track tape recorders – record, transmit, erase, record again. And they’re still working.
Both Voyagers were initially sent to Jupiter and Saturn, where they sent back images of Jupiter’s giant red spot and Saturn’s rings. They also sent back data on erupting volcanoes on Jupiter’s moon Io; hints of an ocean below the frozen surface of another Jupiter moon, Europa; signs of methane rain on Saturn’s moon Titan.
After completing these explorations, Voyager 1 used Saturn as a gravitational slingshot to boost itself toward the edge of the solar system, while Voyager 2 journeyed on to Uranus and Neptune. It is the only spacecraft to fly by those outer planets to date.
Since 2004, Voyager 1 has been poking around in the plasma bubble that surrounds the solar system (news to me! I didn’t know we traveled through the galaxy in a plasma envelope!). Changes in recent data suggest that Voyager may be ready to break through to “the other side”. When it does, Voyager 1 will be in entirely new, unknown territory: the space between the stars.
These days, a handful of engineers listen for the Voyagers from a satellite campus not far from the NASA Jet Propulsion Laboratory, which built the spacecraft. 20 part-time scientists analyze the data sent back. Even with the cameras turned off, each probe still has five active instruments for measuring magnetic fields, cosmic radiation and charged particles from the sun. They also carry gold-plated discs containing multilingual greetings, music and pictures — in the off chance that intelligent species come across them. The spacecraft have enough fuel to last until around 2020.
In 1979, the first Star Trek movie, Star Trek: The Motion Picture, fielded an intriguing speculation about what could happen if Voyager (the movie called it Voyager 6, which never happened) met with an alien civilization that sent it back to Earth. V’ger has achieved consciousness, and wants to meet its creator. It has questions!
As a Trekkie, and old enough to remember the first series and the Voyager launches, I just hope that if our wandering mechanical children ever return home, there will be a Lt. Ilia and Captain Decker waiting for them.