We dream of going to the stars, but the reality is that we haven’t made it any farther than our own moon. We’re reaching for Mars now, but to date, no one has gotten farther than the Voyager spacecraft. Voyager 1 and 2 started their epic journeys in 1977 — that’s 40 years ago this year.
So where did these spacecraft get their start and where are they going now, after their four decades in space?
For machines that have been flying through space for 40 years, the Voyager probes, for all their size, have less computing power than your favorite digital watch. The equipment is so well built, though, that it’s still sending back information even now, 40 years after launch.
They’re doing all this while working in the coldest, darkest and most inhospitable environment known to man, protected from any electromagnetic inference. EMI testing is designed to test a device to see how it will respond to electromagnetic fields and is still used today to determine the kind of shielding a new device will need before it enters the market.
The Voyager mission almost didn’t happen — it was contingent on a launch window that was only open for a few months in the late 1970s. If they missed that launch window, they wouldn’t have another opportunity to view all the outer planets for another 175 years. On top of the limited launch window, there was also the problem of funding — the grand tour of the solar system was pared down to end just after Saturn thanks to Congressional objections.
After all the work wrapped, Voyager 2 launched on August 20th, 1977 and Voyager 1 launched less two weeks later on the 5th of September. The goal was to save as much fuel as possible by using each planet’s gravitational field to slingshot farther out into the solar system.
The Voyager missions were initially designed to last four years, eventually reaching Jupiter and Saturn and observing those gas giants up close for the first time. In spite of the budgetary objections, the researchers made a probe capable of continuing well past its original destination. When they bypassed Saturn and had no equipment problems, they just kept going — past Uranus and then Neptune.
The two Voyager probes have made some of the most iconic discoveries in the last four decades of space travel. In addition to being the first manmade device to fly past all the outer planets in the solar system, the probes discovered multiple new moons at each of the four outer planets and were the first spacecraft to see that Saturn wasn’t the only planet with rings.
Voyager 1 spotted active volcanoes on Io and lightning on Jupiter. Both spacecraft discovered the first indications of interstellar oceans on Europa. In 2012, Voyager 1 was the first human-made object ever to leave our solar system. Since then, it’s been sending back data about the kind of things we can expect to find in interstellar space.
The Voyager probes weren’t just designed to send back data from their epic journey to the stars — they were our way of saying “hello” to any life forms we encountered out there. Each probe contains a Golden Record that contains language information and data about planet Earth, just in case someone out there is curious about us or why we might have sent a compact-car sized satellite out into the universe. For the mission’s 40th anniversary, NASA recently took suggestions for a 60-character message to send out to the spacecraft.
After 40 years in space, where are the Voyager spacecraft now? NASA is happy to keep track of their progress for you with a handy tool that ticks upward as the probes travel farther and farther from home.
Right now, Voyager 1 is just shy of 13 billion miles away from home and moving at approximately 38,000 miles per hour. At that distance, it would take light from Earth 19 hours and 15 minutes to reach Voyager 1. If we could move at the speed of light, that’s how long it would take us to reach the probe’s current location.
Voyager 2 is quite a way behind its twin, despite being launched 16 days earlier. The second spacecraft is about 10.5 billion miles away from home and moving slightly slower than Voyager 1 at 34,000 miles per hour. At the speed of light, it would take us 15 hours and 50 minutes to reach Voyager 2’s location.
Both probes are still going and still sending data back to earth. It’s estimated that both will continue to send information back to Earth for many years to come, likely finally losing power sometime between 2025 and 2036.
The Voyager probes were our first foray into interstellar travel and the first devices that made their way outside our solar system. Raise a glass to our first great explorers and look forward to all the information Voyager 1 and 2 will send back home before their lights finally go out.