Voyager I just became the first man-made object to reach interstellar space -- and it’s running on technology that’s decades older, slower and less complex than whatever you’re using to read this page.
Launched in 1977, the Voyager’s computing power was impressive for its time. The spacecraft was designed to run most of its operations itself, since the billions of miles separating it and Earth make communication laggy. To accomplish that, Voyager has three interconnected computer systems: one to control the craft’s flight and altitude, another to control its instruments, and a third to manage the first two. The computers can process about 8,000 instructions per second -- a fraction of the capability of your smartphone, which handles upwards of 14 billion each second. With memory measured in kilobytes, they can hold only hold a few thousand words worth of text.
Since Voyager’s original mission involved documenting Jupiter and Saturn, it also has a range of scientific instruments and several cameras on board, including a narrow-angle television camera. NASA shut off the cameras in the early '90s to conserve the craft’s dwindling power supply, and they couldn’t turn them back on if they wanted to. The camera is so antiquated, NASA says, that the agency no longer has the software or computers needed to analyze its images. So instead, Voyager focuses on measuring things like magnetic fields, plasma waves and cosmic rays.
As for that data, it gets stored on an 8-track digital tape recorder and played back every six months. Voyager transmits information back to Earth using a 23-watt signal. For comparison, my college radio station broadcast on a 20-watt signal and couldn’t be heard even a few blocks off campus. It is, per NPR, about eight times stronger than the average cellphone.
Undoubtedly the greatest piece of technology on-board the Voyager, however, is a legendary disc known as "The Golden Record” -- quite literally a gold phonograph record packaged with a cartridge and needle and loaded with everything aliens might need to know about Earth. That includes 115 images of humans, animals and airports, spoken greetings in languages from Akkadian to Chinese, a message from President Carter and an “eclectic 90-minute selection of music.” Scientists also printed iconographic instructions on the record to clue extraterrestrials in to how they work.
Of course, as Carl Sagan pointed out at the time, Voyager is far from any actual planets -- and only getting farther. It will be 40,000 years before the spacecraft encounters another planetary system. If phonographs and 8-tracks seem outdated now, just imagine how they’ll look then.