Galactic time capsules! What could go wrong? The twin Voyager 1 and 2 spacecraft were launched in 1977. They’ve since passed the orbit of poor old ex-planet Pluto and are in the “heliosheath”, a layer where the solar wind is slowed down by the pressure of interstellar gas (apparently). Both spacecraft continue to send data about their surroundings via something called the Deep Space Network. (But no more pictures—the cameras were turned off in 1990 to save power and memory).
I haven’t been able to figure out from my inept googling from what, exactly, the Voyager spacecraft are made. They run on really amazingly unsophisticated computers and are powered by radioisotope thermoelectric generators (RPGs) in beryllium cases. I would imagine mostly thin layers of metal, glass and polymer, held together with some of those fancy temperature-resistant adhesives developed specially for the space program but don’t quote me on that if you are writing an assignment that will count significantly towards your final grade. Do your own inept googling.
Apparently the probes will run out of power by about 2020 after which they will drift, at the mercy of nearby gravitational fields. They may not ever escape our galaxy and, according to some guy at the Guardian, “will probably join the celestial swirl around the black hole at the centre of the Milky Way, and could remain there long after our expanding sun engulfs Earth in a few billion years”.
But will they physically last a few billion years? What happens to stuff, out there in space? Most degradation processes on earth need oxygen. Moisture helps too. Neither of these things exist in space. It is also very cold. So most things could probably just hang around until they get taken out by an asteroid or plunge into a sun.
But there is a lot of dust hurtling around. Our moon turned out to be pretty dusty, and the dust was particularly sharp. The astronauts had some problems with it scratching up their visors and scratching through their Kevlar-ish boots and so on. But the sort of dust out in space (SPACE DUST) is way smaller than lunar dust—so small and so fast that when it hits something it turns into a “quasi-neutral gas of ions and electrons” (plasma). Plasma might create radio signals that could damage electrical equipment they hit, like an electromagnetic pulse would. But does it actually physically damage the material? My google searches didn’t turn up a definitive answer, but I wonder if the spacecraft would, on some nano-level, start to resemble Swiss cheese. (Incidentally, is this also what happened to early astronauts’ eyeballs? I am so not going on that Mars expedition.)
Also there’s a lot of radiation out in space—I’m pretty sure those NASA braniacs chose materials that were relatively resistant to ultraviolet and all those other more powerful forms of radiation, but on a molecular level some materials may be being altered. If they’d painted Voyager 1 red, for example, it probably wouldn’t be red anymore.
And speaking, as we once were, of time capsules—both Voyager crafts carry a copy of the ultimate time capsule (the “golden record”). Our message to the stars comprises a 12-inch gold-plated copper disk, carrying the sounds and images of Earth. Each disk is encased in an aluminum jacket. The capsules also hold a cartridge and a needle and engraved playing instructions. Uranium-238 is electroplated onto a two-centimetre area on the cover, so that our alien friends (or space-dwelling descendants) can determine how long it’s been since the craft was launched. (Something about measuring the amount of “daughter elements” compared to the remaining amount of 238). The 115 (only 115!) images on the disk were encoded in analog form, and the sound selections designed for playback at 1000 rpm. I hope our alien friends have eyes and ears and aren’t violently allergic to gold (unless they’re Cybermen, in which case hahaha suffer), or at least that our descendants get some good lols.
Issue two of Materiality (the TIME issue) will be published in late June or early July. Stay tuned!