[gonzo41]

There's a great ROI on these, I don't know why we're not sending more just like it with updated packages.

[btilly]

That's because the planetary alignment that let us send them only happens once every 175 years.

https://en.m.wikipedia.org/wiki/Grand_Tour_program

[lloeki]

> let us

New Horizons would like to have a word.

[KineticLensman]

New Horizons, like many other spacecraft, used gravity assists from planets (Jupiter in its case) but the specific combo of assists available to Voyager will not in fact occur again until the year 2224 [0].

[0] http://www.gravityassist.com/IAF3-2/Ref.%203-143.pdf, section 3.4

[lloeki]

Sure, I mean we won't get to do a Grand Tour again anytime soon but we can and did send things either to planets or heliopause and beyond.

As a nearby comment mentions, Voyager were flybys so now that it's done and even if we could ROI may very well be lower than sending more focused orbiters (for planets and moons) or deep space crafts (for peristellar/interstellar)

[btilly]

The question is what "just like it" means.

My point was that we can't send more "just like" the Voyager trips. But we can send other things on trips that resemble it in some way.

[jl6]

We are probably doing even better than that. The Voyagers were flybys, which naturally limited the amount of time they could spend observing each planet up close. This is why we only know what one side of Triton looks like.

Voyager’s follow-ups have been missions like Galileo and Cassini, which stayed in orbit around Jupiter and Saturn respectively, allowing more detailed observations with better instruments. It looks like the next priority is Uranus:

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

[DylanSp]

Uranus was the next priority from the most recent decadal survey; there's a couple of missions to the outer planets that are farther along.

- The Jupiter Icy Moons Explorer is a European probe that was launched earlier this year, it'll be studying the moons Europa, Callisto, and Ganymede.

- NASA has Europa Clipper scheduled for launch next year, that'll be taking a close look at Europa.

- NASA also has the Dragonfly mission in the works to explore Saturn's moon Titan using an octocopter, currently planned for launch in 2027.