Kerbal Space Program: 11.5 Ton Stock Grand Tour

At long last, after far too many hours, it is here! You can download the Magnum Opus II here: https://www.dropbox.com/s/58absqyrsgg...


All the way back in November, I did a low-ish mass conventionally fueled mission to Moho to prove to someone that it could be done with a reasonably sized rocket without resorting to extreme optimization... But that just made me want to extremely optimize. I got a Moho mission well into the single digit tons, before finding out that I had accidentally optimized the vacuum segment to pretty much the world record.

I set myself the goal of doing a grand tour in under 100 tons, which I was coming in significantly under. I decided to check what the record was just in case (Camacju/Proxima's 14.47 ton "Chaotic Ambition"). Seeing that I was pretty close, I decided to fuse my ideas with her ideas to create the 11,999kg Magnum Opus. It was a colossal failure, with my fuel usage estimates being severely off in places (and my inefficient gravity assists that I just am now learning). The mission was eventually done in at Eve by an errantly placed decoupler which made the Eve lander unusable, but I wouldn't have had enough fuel anyway.

Only slightly deterred, I went back to the drawing board and improved the design, taking care of some of the most egregious wastes of mass and tightening the Kerbin ascent margins. This allowed me to take 35% more xenon (which turned out to be way too much) while still being over 500kg lighter than the original. I was a bit fed up with flying by that point, so while that much excess xenon is quite the waste of mass, the alternative was rage quitting halfway through. Thus the mission is an awkward mix of very efficient flying and impatient brute force. Shown in this video is that voyage, the voyage of the Magnum Opus II.

It likely won't be any time soon, but I am confident I can design a sub 10 ton grand tour craft, but I likely lack the patience to fly it. An in depth analysis video about how possible this is will be posted shortly.

A note about cheese, how low the record can go is partially defined by how far into the gray area of what is and what isn't an exploit one is willing to go. I didn't want to really venture far into the gray, so I set myself the goal of using no tricks that the previous record did not use (I did end up using the container jetpack refueling, which is probably intentional).

I can provide the quicksaves and such upon request if anyone wants them!

Summary of optimizations and alternate choices over previous record:

General: Engineer brought along for the ride to reap the benefits of the EVA construction tool, only one jetpack+cylinders used, refilled at a cargo storage unit. Xenon all stored in small tanks that are jettisoned fairly often (in practice I often let empty tanks pile up before removing them as I didn't need the extra efficiency).
Kerbin ascent: Replaced landing gear with strangely durable flags, moved fuel to the rear allowing only one basic fin to be used as a front wing, redesigned Eve lander to fit in a smaller cross sectional area, leading to less fairing mass.
Tylo: Removed the reaction wheel and did EVA construction drop tanks, but my poor piloting means it isn't really that much lighter and there's still significant room for improvement.
Vall: Used ion tug for Vall instead of refueling the Duna lander.
Duna: Downscaled to an Oscar B tank for the lander
Eve: My design is a bit worse in nearly every area, but far, far, far easier to re enter because flags are OP. I couldn't get all the engines firing at once, and my rotors ended up heavier, more power hungry, and probably less aerodynamically efficient, but I did manage to delete the reaction wheel and one of the upper stage engines.
Laythe: Removed landing gear, completed ascent on a jetpack to get the ion tug outside of the fairing, shrunk fairing significantly, uses less liquid fuel probably as a result
Everything else: Only took the number of batteries required for each landing, and budgeted for only taking the bare minimum xenon (in practice I took much more). Used the smallest solar panel everywhere except Moho. Used a non retractable solar panel even then. Used flags for Kerbin re entry heat shielding but ended up not being needed due to fuel margins.