RP-64 is my attempt to curate a Kerbal Space Program experience that includes realistic mechanics and limitations, but retains more of the stock aesthetic and more compatibility with other mods than a total conversion like RP-1.
A larger solar system allows more realistically-proportioned rockets and more realistic ascent profiles. Most launch vehicles won't have to coast and then restart their engines just to make low Kerbin orbit.
You don't realize quite how far away Minmus is until you're trying to build a ship that can keep a crew comfortable for two or three hundred hours. The Mun becomes the logical choice for your first crewed landing.
It should always be possible to send an uncrewed mission to a place before you can send a kerbal there.
I've looked at the two main probes-first tech tree conversions with recent updates, Probes Before Crew and Unkerballed Start, and they both make changes that I don't agree with. So I've chosen Bluedog Design Bureau as my reference for how capabilities should progress through the tech tree, and I move a few stock parts to live in the same tier as BDB parts with similar capabilities.
RealAntennas and most life support mods follow the convention that one unit of ElectricCharge represents one kilojoule of energy. Batteries and generators will have their capacities increased to match.
Manually download and install Sigma Dimensions. The last release of Sigma Dimensions that's indexed on CKAN is several years out of date.
Set CKAN to allow mods compatible with KSP 1.10 and 1.11. The mods that we need 1.10 compatibility for are RealAntennas and SolverEngines.
I intend to make RP64 installable with CKAN once I have a version that's complete enough to declare as an official release. Until then:
Use CKAN to install the other dependencies listed in RP64.netkan. Add recommended and suggested packages to taste.
Copy or link the GameData/RP64 folder from the repository into your KSP
GameData.
If you have the Breaking Ground expansion installed, change
SERENITY_ROCS_VISUAL_SPEED to 12 in KSP's settings.cfg.
For game performance reasons, the researchable surface features in Breaking
Ground are hidden if the active vessel's surface speed is above this
threshold. But when Sigma Dimensions is installed, the speed that's compared
to the threshold appears to be scaled down by the square of the solar system
scale factor. At 6.4x, a threshold of 12 causes surface features to appear
at roughly the same speed that we get with the default threshold of 500 at
stock scale.
If you've been playing stock KSP on High terrain detail and you see poor frame rates near the Mun after installing the rescale, RP64 adds a "Medium-High" detail setting that may work better for you.
I like the way Kerbalism handles science, with experiments that have to stay active for hours or days to produce a full return. But it has awkward interactions with contracts that want the player to complete and return an experiment, and if I let Kerbalism run life support I break compatibility with other mods I want to support.
If a future version of Kerbalism has enough improvements to the process system to replace the native modules for USI/Near Future nuclear reactors, I'll consider converting other things that I'm supporting to use Kerbalism.