xkcd #3310: Rejected Space Mission Profiles
Title text:
Although NASA agreed that Voyager 2 'seemed lonely' they decided against launching a companion orbiter mission after further measurements indicated that the spacecraft actually preferred the peace and quiet.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3310/
So, a lot of the turnaround stuff for things like noon missions is done by using the gravity well of the planet and swinging back.
Apparently, the amount of nutrients and fuel required for even one person to be in space for a decade (assuming they’d live that long) and go that far would be enough to make the ship massive. At least double it if it you want to make it back.
To change the delta v of that fatty to turn around at Pluto would be an extra level of insanity. Also, there’d be like, zero boost there and that leg of the trip would be horrendous.