Comment by gregable
2 days ago
Well voyager depended on a solar system alignment that only happens every 175 years(?) so it'd be a while before we get that same advantage again. The longer it takes the further of a head start voyager gets?
2 days ago
Well voyager depended on a solar system alignment that only happens every 175 years(?) so it'd be a while before we get that same advantage again. The longer it takes the further of a head start voyager gets?
That alignment is only necessary to do the Grand Tour, to visit all four outer planets in one mission. Voyager 1 actually didn't do the Grand Tour, it only visited Jupiter and Saturn, you're thinking of Voyager 2. This alignment is also not even necessary to attain the highest speed, Voyager 1 is even faster than Voyager 2.
A flyby of both Jupiter and Saturn can be done every two decades or so (the synodic period is 19.6 years)
https://en.wikipedia.org/wiki/Grand_Tour_program
The headstart doesn't really matter, anything faster than Voyager will catch up eventually
Voyager 1 is traveling at 16.9 km/s.
New Horizons (which has the distinguishing feature of being the fastest human-made object ever launched from earth https://www.scientificamerican.com/blog/life-unbounded/the-f... ) is traveling at 12.6 km/s.
The key part there is that it got multiple gravity assists as part of the Grand Tour https://en.wikipedia.org/wiki/Grand_Tour_program . You can see the heliocentric velocity https://space.stackexchange.com/questions/10346/why-did-voya... https://www.americanscientist.org/article/the-voyagers-odyss...
The conjunction for the Grand Tour is once every 175 years. While you might be able to get a Jupiter and Saturn assist sooner, it is something that would take the right alignment and a mission to study the outer planets (rather than getting captured by Jupiter or Saturn for study of those planets and their moons).
While I would love to see a FOCAL mission https://en.wikipedia.org/wiki/FOCAL_(spacecraft) which would have reason for such a path, I doubt any such telescope would launched... this century.
175 years isn't a lot of time when we speak in humanity's time scale. We've been around 200,000 - 300,000 years.
That alignment will happen many more times in the history of humanity. That is to say, I don't know if a spacecraft to overtake Voyager will be launched on the next alignment or one 10,000 years from now, but it doesn't seem unlikely to happen.
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You’ve given numbers for how fast New Horizons launched, and for how fast Voyager 1 got thanks to the 1-in-175-years boost, but is there an easy way to actually compare them?
IE either what speed Voyager 1 launched at excluding the gravity assists, or what speed New Horizons would have reached if it were launched 175 years after Voyager 1 (to take advantage of the same gravity assists)?
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Starship could be refueled in orbit. That should then be able to reach those kind of velocities with enough capacity to even include a small 3rd stage inside with the payload.
Yeah, Voyager 1 was launched on a Titan IIIE. I don't really want to do the delta v calculations, but if we look at mass to LEO as a rough proxy, Titan IIIE does 15,400 kg and the Falcon Heavy does around 50,000 kg (with re-use). New Glenn can apparently do 45,000 kg. Doesn't take into account gravity assists, but 3x the capacity before Falcon Superheavy or refueling gives us a helluva lot of leeway.
Its not "interstellar speeds" but I'm pretty sure we could get probes further out than Voyager 1 faster if we put the money behind it.