It mostly depends on transfer windows from that point onwards, because the required delta-v varies greatly depending on if the two planets are in the "right" place relative to each other or not.

Duna is usually meant to be your first interplanetary flight as its the first one to come (around day 236 of year 1 with a few days on both sides where it remains cheap), as well as the "easiest" planet to go to.
It has an atmosphere, which makes landing there relatively easy, but both the atmosphere and the gravity are lower than Kerbin's, making going back to orbit relatively cheap as well compared to other places.
It also has a moon, which is helpful for mining fuel if you bring enough vessels (attached or individually).

Eve is not a bad place to go to, landing there is ridiculously easy as its atmosphere is extra thick too.
Getting back into space is much harder though, because the thick atmosphere and high gravity mean that you need serious thrust even compared to Kerbin.
Usually it means either not going back to space or needing a SSTO type plane.
The first window is around day 160 of year 2.

The other planets are further from Kerbin so they cost a bit more to go there but they are fine as well.
Moho, Dres and Eeloo don't have atmosphere or moons, you can think of them like the Mun but further away (mostly accidented terrain like the Mun too).

Jool is a gas giant, so you won't be landing there but it has 5 moons, one of which even has an atmosphere nearly on par with Duna (and more gravity).
It serves as a great target for longer missions that aim to visit all 5 moons on the same trip (landing and getting back from all of them).

Also note that except for Duna and Eve, the travel times are going to be pretty long, and even those two take well over 100 days to get there.
Days are only 6 hours long and years are 426 days long but time becomes much more diluted and it is possible to have vessels going towards several planets at the same time, which is where the alarm becomes really important.


You might want to grab "alarm enhancements" or "kerbal alarm clock" to have a more robust alarm as well as "kerbal engineer redux" that allows you to figure out thrust to weight and delta-v in different circumstances (different planets/moons, orbit or atmosphere).

I don't know if it's the base game's alarm or one of the two alarm mods that adds a transfer window planner, there is also a mod dedicated to this exactly or websites that give you the same data but you will want to have a way to figure those out.
With Duna as an example, from 100km orbit to 100km orbit, you need 1047m/s of delta-v to get there and if you just do a burn to circularise (no aerobreaking and not using the moon) you need another 645 for a total of 1692 (probably a bit more since we are not doing things absolutely optimally but it gives you an idea of what is needed).
Around day 350 of year 1, the cost would instead be 3360 and at the worst around day 200 of year 2, you would need 18319.
Of course, you can treat it like a rendez-vous as well and do it in several stages but the right transfer window remains the cheapest way to go interplanetary.

Gilly (moon of eve) is fun, Jool is cool, Duna is fun just because it’s mars but it’s also a bit overrated. I wouldn’t recommend Eve, Moho, Dres, Lathe (moon of Jool) because they can be tricky.

If by logically you mean, realistically, I would suggest going to Duna next as it would be the next step you could go to Eve I mean, this is a sandbox and we can do whatever you want, but you normally cost more fuel than and it’s really hard to land on plus sen you’re doing science I wouldn’t necessarily suggest it but if you want and maybe you can do as well you can send a couple probes over to get initial science. If you want to mark out places that might be of interest they wanna go to sooner than others.

If you're doing career mode, you'll want to spend your current time setting up infrastructure. My guess is that you've got some solid reputation built up. This means that once you've sent anything to Duna, you're gonna get a whole bunch of Duna contracts. Getting an orbital fuel station, an efficient fuel tanker SSTO, and a reusable modular transfer tug all set up in orbit waiting for the transfer window is a good way to kill time.

Usually after Mun and Minmus i put some big comm arrays in orbit of Kerbol, Eve and Duna so i can always send back science in later missions.

So I went ahead and picked up the Eve mission because it has no time limit. So I'll get to it eventually or I may just build a probe with nuclear engines and use a low thrust Hohmann transfer since the mission doesn't require a crew. I just need to do a fly by and collect science. I may just take orbital readings and transmit them and leave it as my first relay satellite around Eve. Thoughts on that?

I've been using the alarm. I launch 2 kerbal crewed missions, one to the Mun and one to Minmus, and a probe cored auxiliary mission to build my personal space station and my relay networks. I set alarms and run those and then when they are all complete I launch another set of 3. I have a trio of kerbostationary relay satellites, a trio of relay satellites in Munar orbit, and a trio of relay satellites in Minmus orbit.

I'm not sure where to reposition my transfer station. I've mostly been using it for passenger transfers. My most lucrative tourist missions are having splits between the Mun and Minmus so I've been sending launches to Minmus and the Mun, then going to the transfer station and shuffling passengers to dedicated command and lander modules that I refuel in orbit, return the tourists to the transfer station, put them back on the launch vehicles, and head back down to Kerbin once all their itineraries are complete. Not sure where the most efficient place to park the station would be. Its currently orbiting Kerbin at zero inclination just inside Mun orbit but not so close to the Mun that it can enter the Mun's SoI. Its slowly passing the Mun and its going to get inconvenient for transfers soon. Not sure if I want to build a 2nd or even third transfer station to remedy that problem or if there is a better solution. Thoughts on that? Am I going to get offered tourist missions to Eve and Duna?

For next destination it sounds like Duna is the place to head to. I'll get my 3 relay satellites built and headed that way. Is solar still good enough for power around Duna or do I need RTGs?

Space around Kerbal, the Mun, and Minmus are starting to get cluttered with contract satellites. Should I leave them be or scrap a few?

New hires are expensive now so I've been doing rescues to top my roster off since I have staff permanently assigned to places. Any worries on that front?

Solar power is about half as powerful at Duna, so still plenty usable. You have to get out to Dres for RTG's to start being more mass efficient. I'd wager that you should pack exactly one RTG for backup power.

I'd personally scrap all the contract satellites. Maybe save a survey satellite around each body, but the rest can go.

It's been a while since I've gotten that far into a run of career mode, but I seem to recall that the rescue missions never stop, but they do shift towards the places you've just discovered, and attempting to rescue a kerbal from Duna Orbit is a lot less sensible than even a multi-kerbal rescue mission in the kerbin system that hits every body in the system. I'd advise you stock up on astronauts while they're easily available. You'll be able to keep recruiting very lost kerbals, and the missions will keep turning a profit if flown responsibly, but the time expenditure gets a bit weird.

As to transfer stations. Leave your current one where it's at. You'll want to have your main fuel station for interplanetary transfers kinda low to kerbin. Maybe 100km off the ground. The lower your periapsis during your initial ejection burn, the more Dv you can harness from the Oberth effect.

Originally posted by Knux Redbeard:

Solar power is about half as powerful at Duna, so still plenty usable. You have to get out to Dres for RTG's to start being more mass efficient. I'd wager that you should pack exactly one RTG for backup power.

I'd personally scrap all the contract satellites. Maybe save a survey satellite around each body, but the rest can go.

It's been a while since I've gotten that far into a run of career mode, but I seem to recall that the rescue missions never stop, but they do shift towards the places you've just discovered, and attempting to rescue a kerbal from Duna Orbit is a lot less sensible than even a multi-kerbal rescue mission in the kerbin system that hits every body in the system. I'd advise you stock up on astronauts while they're easily available. You'll be able to keep recruiting very lost kerbals, and the missions will keep turning a profit if flown responsibly, but the time expenditure gets a bit weird.

As to transfer stations. Leave your current one where it's at. You'll want to have your main fuel station for interplanetary transfers kinda low to kerbin. Maybe 100km off the ground. The lower your periapsis during your initial ejection burn, the more Dv you can harness from the Oberth effect.

Solar power stays more mass efficient all the way out to Jool, then you start needing it. In reality you only need power for reaction wheels in stock ksp

I'm assuming you play without communication so you can literally do anything you want just build the ship that can go there... If you would like a real test then play with communication Where you have to literally set up satellites and communication networks before you go anywhere.... once you master all of that try doing it with life support

Hey KT, good to see you. Maybe after you have finished KSP (and while waiting for KSA) check out Reentry. I think you and your bride may enjoy it. Cheers!