Project Grand Tourist: a minimalistic Grand Tour of Kerbol System

[Kerberus]

Introduction

Hello! This is my first post on these forums. I got this game the day 0.21 came out and have been playing it since. I learned the basics, visited every landable celestial body, put orbital stations around Kerbin, Mun and Duna, but soon it got a bit boring to explore without any goal and build rovers and bases simply for the sake of having rovers and bases. So, around the time 0.22 came out, I started community campaigns from the wiki, some of which are designed to recreate historical missions. I followed them strictly until "Kerminor 10" mission, which requires to perform an Eve-Moho slingshot followed by triple Moho flyby. Surprisingly enough, even after three flybys I still had plenty of fuel left, and thought: is it possible to visit more planets with a similar probe? So came the idea of Project Grand Tourist.

Project goals and restrictions:

1. Try to visit as many celestial bodies as possible.

2. No funds for nuclear or ion engines, liquid fuel only.

3. Fuel prices has gone up, so FL-T200 is all we can have.

4. No waiting for like 10 orbits for a good maneuver: if you can go somewhere now, just go somewhere now.

I prefer a minimalistic approach to gameplay and don't use any automation/botting plugins, so everything will be done manually. There's also a cool trick I found recently: if you pull a maneuver node controls in, instead of out, it allows for a greater precision up to decimals, it is insanely useful.

So, I hope to deliver and upload a report of the first part within an hour or so.

[Kerberus]

To avoid a temptation to wait for optimal launch windows and for keeping a better track of elapsed time, I decided to start a new game for this mission.

Part 1: Inner Kerbol System

Grand Tourist: Ready to launch!

Liftoff!

SRB's decoupled, starting a gravity turn. A single LV-T45 is enough to go to orbit. This stage will drop just before finishing the 100 km circularisation burn, with interplanetary stage finishing it.

Eve is the easiest planet to get to, so let's go there.

I forgot to set up the timer and missed the burn time, but only slightly. It doesn't matter, we have plenty of fuel to correct the course later. By the way, the interplanetary stage also uses FL-T200 and 48-7S. The choice for engines is simple: weight.

Year 1, day 1, 00:30, Kerbin and Mun.

Course set to Eve, decoupling interplanetary stage. From here, we're on our own.

The initial course was set to impact Eve, so the interplanetary stage can crash leaving no space debris. After a couple of minor corrections, the last will take only 7 m/s of delta-v and should bring us to Moho after Eve flyby.

First Eve flyby.

We plan a slight (only 3 m/s) adjustment after the flyby. First, as we didn't align orbit inclinations, new orbit should intersect Eve orbit at the point of previous Eve encounter. Second, I calculated the orbital period, and not only the orbits should intersect, but we also should encounter Eve after exactly 3 full orbits since previous encounter. This doesn't break the rule of "no waiting for several orbits" because we simply can't go anywhere else now. Regardless, I hope there will be no more waiting from now on.

Moho flyby.

Two orbits after leaving Moho, we can meet Eve again as predicted before, after a 262 m/s burn at the apoapsis.

After that planned encounter we still can't get to Duna, but we can't wait also, so what do we do? We plan our encounter so the new orbit will have exactly the same orbital period as Eve, which allows for two Eve encounters in a row!

Second Eve flyby (first in this series).

We plan that third (second in the series) Eve flyby so after just one more correction, we get Duna encounter.

Third Eve flyby, much closer than the previous ones.

Only a 2 m/s apoapsis burn should bring us close to Duna.

We correct our course so after leaving Duna, we can plan for another Eve encounter to kick us anywhere we want. The node thingy shows 600+ delta-v requirement, this is clearly a glitch, it's really less than 100.

Duna flyby, with Ike in the background.

After leaving Duna, I realised that going back to Eve right now is not the best idea, as we will be approaching it parallel to its orbit and won't get neither much speed nor course change from this encounter. Instead, we aim for Kerbin, and a planned 12 m/s burn near Kerbin would bring us to Eve from a better angle.

Kerbin flyby.

At this point we have 3/4 of fuel left and a pretty good orbital speed, and it looks like we really can get to Outer System at this point...

To be continued. I can't play all day straight, have to work sometimes too.

[Kerberus]

Part 2: Outer Kerbol System

So, Grand Tourist has completed the first part of the journey, gained some speed and is ready to go to the outer part of the System. One more Eve encounter should be enough to bring us to any of the remaining planets. The choice is between Jool first and Eeloo first, and though it looks that both are near each other, Eeloo would require flying in an almost straight line, not to mention the inclination. And choosing between 84 and 800+ m/s of delta-v is simple.

Fourth Eve flyby. This time, we almost touch the atmosphere.

Dres has somewhat inconvenient inclination, but Jool has large enough gravity well to shape our resulting orbit however we want. A planned 107 m/s burn is enough for Dres encounter on the way back.

By the way, it's been almost 3 years since the start of the journey, and getting to Dres will take 2 years more.

Jool, Laythe, Vall and Tylo.

It's a shame we couldn't get any closer because Tylo is in our way. Even more closer, and it's Kerbol escape trajectory.

We can fly right above Dres surface, and at this speed the flight is pretty scary. It's like a space rollercoaster: you are falling onto the planet, then go up really fast.

5 years since mission start. The only remaining planet is Eeloo, ant it's on the opposite side of the Kerbol System. So we just stay in the new orbit and wait... actually, no, we don't wait. We correct our orbit for another Jool encounter, which should align our inclination with Eeloo orbit and give us Eeloo close approach. The whole thing will take 4 more years and require just one 107 m/s burn.

I wouldn't mind having 1.000.000x and 10.000.000x warp options in the game. 20+ minute waiting was extremely boring.

And finally, Eeloo flyby.

Mission: success.

Tour completed in 9 years and 62 days with 63% fuel left.

Conclusion: A FL-T200 is actually too much, this kind of mission could be done on a T100 with ease or even with tiny fuel tanks. Or we could just take a lot of scientific equipment with this probe and it still would be the same.

And here's a little twist. Our Eeloo trajectory was not just random. Our periapsis now almost touches Kerbin orbit, and we can easily get another Jool encounter.

So, there are several ways to end this mission:

1. Just finish it and eject the probe out of Kerbol System.

2. Aerobrake at Kerbin and try to land on Minmus.

3. Continue mission and explore the moons of Jool.

Which one is it?