Voyager Flight Path possible? If so help needed.

[theh5]

Hello, I am trying to make a probe to fly from Kerbin to Duna and all the rest of the outer planets. The closest I could find to a forum of this was a challenge: http://forum.kerbalspaceprogram.com/threads/37974-Optimal-gravity-assisted-grand-tour-%28AKA-Voyager-like-mission%29-challenge?highlight=Voyager+flight+path - However it was not sufficient.

Gameplay question: Is it possible to do a Voyager flight path - http://abyss.uoregon.edu/~js/images/voy_traj.jpg (or similar) - with as Little as a ion Engine, Voyager didn't use much more it relied on gravitational propulsion.

Tutorial question: A date when it would be at all possible would be appreciated and/or even a finished flight path.

Edited August 14, 2015 by theh5

[Sharpy]

This may be helpful.

[Thomassino]

Voyager went to Jupiter first, which gave it enough velocity to have an escape trajectory from the sun and have an encounter with Saturn. Gravity of Duna probably isn't sufficient to reach for example Jool's orbit. If you really want to do gravity assisted trip, you should make an encounter with Eve, Kerbin and repeat until you are on a good trajectory. Or try Outer Planets Mod. It would be awesome if you'd do in it

[PLAD]

I have looked and looked for a flight that would go Kerbin-Duna-Dres-Jool-Eeloo, but have never found one. I think the problem is that Duna and especially Dres are too small to have much effect on your flight path, if that flight path has enough energy to continue on to Jool. I essence you are looking for a flight that goes to Jool and on the way happens to cross the orbits of Duna and Dres while they are there, and that is a very unlikely arrangement. (Once you are at big heavy Jool it can throw you anywhere in the system, so the Jool-Eeloo leg is easy.) If you use my Flyby Finder here is a sample flight that goes Kerbin-Duna-Dres, enter the following numbers in the input fields like so:

....................................Start at...........1st encounter............2nd encounter

....................................Kerbin..............Duna........................Dres

Earliest Search Date.........50...................65...........................100

Search period..................50...................400.........................1000

V at SOI max: 3000m/s

Note that FF still uses Earth time (24hours/365 days) to define dates.

If you study this flight you will see that you are in an orbit around the sun that crosses Kerbin, Duna and Dres' orbits, by luck they are there when you cross their orbits. Note you go out to solar apoapsis and then back in to the Duna encounter, then back out to Dres. Hardly a Voyager-type path! You could try and find an encounter with Kerbin after the Dres flyby that would pump up your orbit. Or you could go straight to Jool first, Jool can send you just about anywhere if you can get to it, so you could maybe go Kerbin-Jool-Eeloo-Jool-Dres-Jool-Duna, if you allow a couple of coasting orbits between the encounters, but none of this is remotely like what Voyager 2 did. (And Flyby Finder can't handle multiple orbits between encounters so you'd have to wing it.)

Note that if you use the Real Solar System mod you can simulate Voyager's path quite nicely, since the real Solar System has 4 big heavy gas giants that can dramatically affect your ship's path. Flyby Finder for RSS shows this path in its tutorial.

PS- executing multiple flybys is not easy, you will need a node editor like Mechjeb's to set them up, and even then they are unforgiving of travel-time errors. But as you observe, they are a powerful way to reduce the delta-V required for a mission. I'd love to see a solution if you find one!

[xtoro]

The path that voyager 1 took only happens every 176 years when the planets line up for such a maneuver. In KSP, it would be a lot of timewarping to find a window like this. But I don't even know if it would ever happen as I'm not sure what the ratios are for planetary orbits around the sun. It may be possible that it never happens because at some point, the planets wind up in the same positions as they were when you started a fresh save.