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Comment by listic | Hacker News Reader

Have we been able to launch faster spacecraft since? I'm thinking whether there could potentially be a newer interstellar probe that could overtake the Voyagers 1 and 2 on the way out of the Solar system.

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Not really, no. These probes don't really accelerate by burning fuel; instead they pick up velocity by doing a bunch of gravity assists. The more of these you do, the faster you go, but sometimes you have to coast around the sun for years to align yourself with the next gravity assist, and this gets worse and worse until you hit solar escape velocity. Using this method, your final interstellar velocity will just depend on how many objects you can slingshot around on your final 'kick' out of the solar system. (So, in other words, you can get in the same ballpark as Voyager, but not orders of magnitude faster.)

Here's a video of what it takes "simply" to get out near Jupiter, nevermind out of the solar system. https://www.youtube.com/watch?v=ktrtvCvZb28

The Voyager spacecraft took advantage of a special planetary alignment that won't happen again for over a hundred years.

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Having said that, if by 'spacecraft' you mean something weighing a few grams, the Starshot program might be able to obliterate the Voyager records. https://en.wikipedia.org/wiki/Breakthrough_Starshot

What if you use an ion drive or other propulsion that uses less fuel, and run it for years or decades? Yes, it generates little thrust, but won't it add up over long timescales?

That'll certainly help a bit--you'll pick up several km/s of delta-v--but even this will still be pretty irrelevant in terms of interstellar distances.

> a laser with a gigawatt of power (approximately the output of a large nuclear plant) would provide only a few newtons of thrust.

wow... that's not very efficient...

For anyone who wants to play with doing slingshots around the solar system, there's always Kerbal. Or alternatively there's Spaceflight Simulator https://play.google.com/store/apps/details?id=com.StefMorojn... for which https://xkcd.com/1356/ is true for me.

Only five probes were launched with the ability to leave de Solar System, but the Voyagers are still the fastest ones...

https://en.wikipedia.org/wiki/List_of_artificial_objects_lea...

Depends on what you mean. There have been recent craft (New Horizons and the Parker Solar Probe) that were launched to a higher velocity than they Voyagers. However, the Voyagers used gravity assists from the gas giants to achieve a high final velocity. It seems unlikely that we'll be able to overtake them unless/until we step up to a more powerful form of spacecraft propulsion.

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