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How do the Voyager Spacecrafts avoid crashing into objects in interstellar space?

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    $\begingroup$ There's not much to run into. Interstellar dust ( 1/10th of a micron across) is at a density of one grain per 1,000,000 cubic meters, That's the thing about space: there is a lot of it. $\endgroup$
    – Woody
    Nov 28, 2023 at 2:07
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    $\begingroup$ Although that figure is already pretty dense. As a benchmark, a spacecraft 1m² in cross section travelling at 1km/sec will traverse 1,000,000m³ every 20 minutes or so. $\endgroup$ Nov 28, 2023 at 7:59
  • $\begingroup$ I would think that dust density is even less at the 130+ AU distances that the Voyagers are at now. They are so far away that the cosmic wind is stronger than the solar wind. However they are now venturing into or at least towards the hypothesized area where comets originate from known as the Oort cloud. Although I would think it's highly unlikely that they will run into a comet or any of its debris. $\endgroup$ Nov 28, 2023 at 15:08
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    $\begingroup$ Keep in mind that asteroids have been flying through a much more crowded environment for billions of years. They've been battered around along the way, but out of the millions of asteroids in the belt, only a couple collisions have been seen. If collisions were common enough to be an issue for these probes, the asteroids would have been smashed to dust long ago. $\endgroup$ Nov 28, 2023 at 15:16
  • $\begingroup$ That would be almost exclusively by luck, unless you're suggesting that Voyagers have first detection mechanisms and then precise, local movement control? I'm 'guessing' that first because when 50 years ago I worked for a while in aircraft design, most of my time was spent on reliability, specifically including theoretical collisions; further because I happen to have been lucky enough to discuss exactly that with a NASA space-station designer assigned the same research. We should plan for what happens if, but that 'if' is almost too remote to plan for. $\endgroup$ Nov 29, 2023 at 23:56

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They don't. The Voyagers have no way to detect objects in the vicinity. We aren't using telescopes to look for objects in their paths either. We can get away with this because space is empty. Even in the densest region of the solar system (the asteroid belts), the average distance between objects is on the order of 1 million km.

When the Voyager program just started, there was some doubt if we'd be able to fly through the asteroid belt without hitting anything. Pioneer 10 and 11 were built in part to see if we could.

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