The Voyager spacecraft, with their 36-year-old systems and 68KB of computing capacity, may soon exit the solar system.
Reading through GCN’s recent anniversary issue, I was struck by how far technology has come in three decades. Look at the old Cray-X-MP compared to the Titan supercomputer of today. I began to wonder if any of that old technology was still in use.
For the most part, any technology that was in government service 30 years ago has been retired. But there is one area where old technology is still alive and well, working in the one place where we can't refresh it, even if we wanted to: space. And in at least two cases, that technology is working just fine.
Two satellite workhorses, the Voyager probes, are contributing data to NASA’s current work mapping the heliosphere — the tail of solar radiation and particles trailing off away from the sun — for the entire solar system. Launched in 1977 (the year the Apple II was born), they are both still functioning, with Voyager 1 traveling 11 billion miles away from the sun. It's very possible that Voyager 1 will be the first man-made object to leave our solar system.
The Voyager space craft are identical. They have 10 instruments that record data about the planets they pass, and so far they’ve explored Jupiter, Saturn, Uranus and Neptune before heading off toward deep space to find the edge of the solar system. Other than one failure, all of Voyager's systems are still working fine, even equipment that, based on our experience with their Earth-bound counterparts, might not seem so durable.
In all, there are three types of computers on a Voyager, with a total capacity of 68KB. The Flight Data Subsystem, for instance, is a single 8-track digital tape recorder. The 8-track records data and plays it back to Earth every six months. And despite its 36-year-old technology, the Voyagers have a long list of impressive accomplishments.
So Voyager may be the most successful computerized system ever created. And it's just really cool, or should I say groovy, that it includes an 8-track tape deck. I suppose when people say that they don’t make things like they used to, looking at Voyager, you’d have to agree. I've had brand new computers die after a few years of terrestrial use. And 11 million miles away in space, some 1970s’ technology is still answering questions about the universe.