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Realistic Progression Zero/One - Career mode for Realism Overhaul

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Welcome to Realistic Progression One, the heavyweight career addon for Kerbal Space Program's Realism Overhaul.

RP-1 is a career mode for RealismOverhaul with minimal install requirements, and with fair and balanced gameplay. Our aim is to allow players to enjoy RealismOverhaul in career mode, without installing a huge number of modules on top of those required by RealismOverhaul itself. However we also wish to ensure that RP-1 works with as many additional mods as possible; we use a fresh fully icon rebuilt Tech Tree for the basis of career progression, and try to place as many parts from other mods as possible in a historical fashion. Right now a good number of nodes lack much in the way of parts allowing for placement of balanced historically appropriate parts in those nodes.

RP-1 is a community effort, and your contributions are appreciated. You can report issues on our issues page, and access the source code on github.

When starting the game, the balance should be similar to KSP's normal career, so we recommend "Moderate" or "Hard" settings. If playing without part unlock costs, it's recommended you drop contract funds payouts to 20% or less to maintain balance, since in real life the research programs and the setting up of factories cost much more than serial production.

Tooling: Tooling costs significantly adjust the play cost of craft. As you adjust tank sizes wait till the end of craft saving to tool the tanks so you do not waste funds. Maintenance: A small cost of the infrastructure and wage cost is rolled into play. This puts a minimal drag on program growth. KCT Integration: KCT is heavily integrated and using the RP-0 Settings is important. Make sure you have lower rated launch pads availble and don't just focus on one maximum upgraded pad for all use. This will lower costs and rollout times if you use the smallest pad needed for the craft launched. There are 7 levels of pad and R&D. Crew Training: Each 'naut needs to be proficient and mission trained to fly on a craft. Proficiency training will end after a time and mission training is good for one mission and is then lost after recovery. Crew readiness and retirement: After each recovery crew are on leave for a short time. Each crew also has a retirement date that rolls forward after each mission. Contracts: Many contracts leading through a rough historical path are available. One contract will add a beginning node of parts that are available from the start but you may not want cluttering the VAB/SPH. Parts in this node have a purchase price of 1 fund and this contract will auto-complete seconds after leaving the mission control the first time. Tree: A massive tree orginized along a historical frame. Two gating tech patchs (Material Science, and Electronics) limit what nodes are available in a general sense. Most nodes have custom icons usually taken from the profile of relavent hardware from the node. Using KCT the nodes will have an orange interior when purchased with points and the normal purchased colors after KCT delay times pass. Part Tags: launch costs are significanlty affected by the types of systems on the craft. For instance toxic hypergolics require special handling and disposal. So a solid rocket motor driven craft may at first glance seem more expensive but my indeed be less costly due to reduce launch costs. Engine Variations: Many engine variations are available and purchased via the Engine GUI. In the Tech tree these will appear and may have some variable cost however this cost is not real and purchasing this "Part" will have no cost or impact whether it is purchased when looking in the Engine GUI.

This top-post is jointly maintained by pjf and NathanKell and many others.

License: CC-BY-NC-SA-4.0

Release Thread: Github Repo: Discord Link:

Requirements: - Realism Overhaul and all of its required mods (including Real Solar System) - Module Manager - SXT Continued (Needed for engines) - Contract Configurator - Custom Barn Kit - Deadly Reentry - Ven's Stock Revamp (Needed for engines) - Kerbal Construction Time (Infrastructure, Build Time, Rollout Costs) - DMagic Orbital Science (Science parts) - DMModuleScienceAnimateGeneric

Highly Recommended: - B9 Procedural Wings - Connected Living Space - Hangar Extender - Kerbal Alarm Clock - KRASH - KSCSwitcher - MechJeb - Procedural Fairings - Procedural Parts - RCS Build Aid - RealAntennas - RemoteTech - SCANsat - Science Situation Info (tells you what science parts work where) - Ship Manifest - ROKerbalism - TAC Life Support - TestLite - Test Flight - Texture Replacer - Toolbar

Suggested Mods - Raidernick's Mods (especially US Probes and Soviet Probes) - FASA - Janitors Closet - Kerbal Engineer Redux - Kerbal Renamer - kOS - ROEngines - ROCapsules - Real Scale Boosters - Bluedog Design Bureau - Soviet Engine Pack - Taerobee - Waypoint Manager

Note that more effort has gone into balancing earlier nodes than later nodes. Your feedback and assistance in balancing all nodes is appreciated!

Procedural Avionics

Procedural Avionics is an addition to RP-0 which allows you to build custom avionics units, instead of relying on pre-build avionics (think Procedural Parts, except for avionics). In fact, Procedural Avionics was built on top of Procedural Parts, we just took the Procedural Battery that RP-0 had and added a scalable avionics unit inside of it.


In RP-0, avionics units have a maximum amount of mass they can control. When using a procedural avionics part, you'll notice it had a tonnage slider. Sliding this slider increases the amount of mass this part can control. The maximum amount of mass it can control is limited by two things:

  • Part Efficiency
  • Part Volume
  • Configuration (more on this later)

Efficiency is limited by tech level. Volume is limited by part size and shape. Tonnage can further be limited by setting the appropriate values in the configuration.

In the GUI, you'll see a Percent Utilization field in the editor that ranges from 0% - 200%. It's not always the best idea to just max out the avionics slider, more on that later.


Procedural Avionics can have different configurations. For instance, booster avionics might not be toggleable, use a lot of power, but be fairly light (for the amount of mass they can control), while probeCore avionics would be more efficient power wise, but a bit heavier (due to their robustness). Upper stages might lie somewhere in the middle.

Optimal Utilization Percentages

As part utilization goes up, so do part cost and part weight. However, these do not rise at the same rates. Consider this example: as you try to fit more avionics controls into the same amount of space, you should probably invest some effort into making those controls smaller and more efficient. The smaller and more efficient you try to make those parts, the more they cost (and the higher the cost per controllable ton). However, since these parts are more efficient, while your overall part mass continues to rise, your mass per controllable ton actually decreases. Because of this, we actually get two different "curves", a mass curve, and a cost curve:

  • mass curve: -(x^2) + 2x (as utilization goes up, additional mass needed per controllable mass goes down)
  • cost curve: x^2 (as utilization goes up, cost rises quadratically) >Note that while utilization is normally displayed as a range between 0-200%, the above formulas treat utilization as 0-100%

Because the actual efficiency of a part depends on its utilization, we run into a problem when trying to configure these parts. Thus, we'll define a "sweet spot" of 100% utilization. If a part is 100% utilized, then their cost/controllable ton and mass/controllable ton will be what's in the configs. Bringing the utilization up to 200% (and reduce the volume accordingly, so you're still controlling the same amount of mass), and you should find your part mass decreased by about 1/3, but your cost to be 4x as much.

It is worth noting that the mass and cost curves here only define the mass of the avionics module portion of the part. As these parts by default also contain batteries, there is additional mass and cost dependant on the size of the part.

Electric charge consumption

Electric charge consumption is not nearly as complicated, as it scales linearly with utilization. At 0% utilization (I don't know why you would ever choose that), power consumption is 50% of its rated (sweet spot) value. 100% utilization consumes 100% of rated value, and 200% utilization consumes 150%. This is true for both the active and inactive power drain rates.

Tech Node Config

Let's take a look at a sample MM config for procedural avionics. I'll annotate what things mean inline.

    name = ModuleProceduralAvionics

AVIONICSCONFIG  # A Procedural Avionics unit can have 
                # multiple AVIONICSCONFIG nodes
    name = booster  # The name of this config

    TECHLIMIT  # Guidance Unit (Starting), 1m
               # We'll define our efficiencies per tech level 
               # Sandbox play will pick the best TECHLIMIT per AVIONICSCONFIG
               # We generally try to add a comment saying what this confic
               # was created from (in this case, the first Guidance Unit)
        name = start                # This is the name of the technology that
                                    # should be unlocked for this to be
                                    # available.

        unlockCost = 0              # This node is free

        tonnageToMassRatio = 26.13  # This is how efficient this node is mass 
                                    # wise at 100% utilization. A higher number 
                                    # here is more efficient. More than 100%
                                    # utilization will cause this to be
                                    # effectively higher too.

        costPerControlledTon = 13   # This is how much the avionics portion of 
                                    # this part costs at 100% utilization.
                                    # Lower is better. This goes up exponentially
                                    # as utilization goes up. 

        enabledProceduralW = 150    # This is the power drain per controllable 
                                    # ton when this part is active, 
                                    # again at 100% utilization.

        standardAvionicsDensity = 5 # This helps make procedural avionics
                                    # match up to their in-game counterparts.
                                    # It's pretty much part mass / part volume.
                                    # Another note about this value: generally, 
                                    # it has no effect on performance efficiency,
                                    # since this just ties the weight of avionics
                                    # to the size of the part. In the end, 
                                    # avionics is still dependant on part mass.

        minimumTonnage = 15         # No matter what values you have set elsewhere,
                                    # this is the minimum amout of control you can
                                    # set this part to.
                                    # This prevents you from using ultra-small booster
                                    # units as probe cores.

        maximumTonnage = 40         # No matter what values you have set elsewhere,
                                    # this is the maximum amout of control you can
                                    # set this part to.
                                    # This prevents you from using unrealistic 
                                    # sized avioncs units early on.

        SASServiceLevel = 0         # The service level of the built in SAS Module.
                                    # All procedural avionics units have SAS modules,
                                    # this value can range from 0-3
    TECHLIMIT # Guidance Unit (Early), 1m
              # An example of another, more efficient 
              # tech node for the same config
        name = earlyAvionics
        unlockCost = 9000           # This node costs 9000 funds
        tonnageToMassRatio = 104.16
        costPerControlledTon = 3.8
        enabledProceduralW = 6.666
        standardAvionicsDensity = 2.7504
        minimumTonnage = 15
        maximumTonnage = 90         # Notice minimumTonnage stayed the same,
                                    # while we've increased maximumTonnage
        SASServiceLevel = 0
    TECHLIMIT # Guidance Unit (Early), 2m, 3m average
        name = basicAvionics
        unlockCost = 15000          # This node costs 15000 funds
                                    # However, if you've purchased the previous node(s),
                                    # it would only cost 6000 funds

        tonnageToMassRatio = 940
        costPerControlledTon = .53
        enabledProceduralW = 5.81
        standardAvionicsDensity = 0.083
        minimumTonnage = 15
        maximumTonnage = 600
        SASServiceLevel = 1
AVIONICSCONFIG # A second config
    name = upperStage

    TECHLIMIT # Able Avionics Package
        name = earlyAvionics             # Notice there is no node with the name 
                                         # of "start".  This will cause the 
                                         # upperStage config not to be
                                         # unlocked until later in the gameplay

        unlockCost = 6000
        tonnageToMassRatio = 52.8169
        costPerControlledTon = 4.8
        enabledProceduralW = 30
        standardAvionicsDensity = 0.2279
        minimumTonnage = 3
        maximumTonnage = 10
        SASServiceLevel = 0
    TECHLIMIT # Agena Avionics Package, with some fudged stats
        name = stability
        unlockCost = 24000
        tonnageToMassRatio = 108
        costPerControlledTon = 23
        enabledProceduralW = 15.625
        disabledProceduralW = 0.625    # Here we have a new node.  This controls
                                       # power drain when the part is disabled.
                                       # this worked the same way as
                                       # enabledProceduralW
        standardAvionicsDensity = 0.07
        minimumTonnage = 3
        maximumTonnage = 10
        SASServiceLevel = 3
    name = probeCore

    TECHLIMIT # Ranger Block I Core
        name = basicScience
        unlockCost = 36000
        tonnageToMassRatio = 4.327
        costPerControlledTon = 4425
        enabledProceduralW = 166.66
        disabledProceduralW = 2.666
        standardAvionicsDensity = 0.416
        SASServiceLevel = 1

        # Since probeCores should be the least mass efficient, we probably don't
        # need to add any restrictions on min/max tonnage
    TECHLIMIT # Ranger Block III Core
        name = miniaturization
        unlockCost = 45000
        tonnageToMassRatio = 8
        costPerControlledTon = 2550
        enabledProceduralW = 133.33
        disabledProceduralW = 2.5
        standardAvionicsDensity = 0.28
        SASServiceLevel = 1
        hasScienceContainer = true      # This enables the ModularScienceContainer


Building your own TECHLIMIT nodes

I have created a spreadsheet here that you can copy and use as a scratchpad to help you configure tech nodes. I'll give a manual walkthrough of what I would expect someone to do here, and I have created a few nodes at the top of the spreadsheet for some early existing parts.

Feel free to update the spreadsheet and create PRs to add new nodes. An example PR can be found here.

  • Create a new line, copying the line above it to get all the formulas.
    • Note: You should only need to edit the values in the blue columns.
  • Take a look at the parts mass, cost, and controllable mass. Put those in columns and D, E, and F respectively.
  • Columns G and H should be what the avionics unit drain is (in kW)
  • Create a part roughly the same size and shape of an existing avionics module unlocked in that tech node.
    • Take note of its volume. Enter this in column G of the spreadsheet. (Note: the KSP UI normally shows liters, but in the spreadsheets it's kiloliters.)
    • Slide the utilization slider down to 0, and take note of its empty weight and empty cost. Put those in columns H and I respectively.
  • Columns L-P should now contain values for
  • For setting
    , I generally halve and double the values defined for the existing avionics part.
  • For setting
    , I just use the value already present in the
    already on this part.
  • For setting
    , I usually just use 1.5x the unlock price of the non-procedural version

There are many cases where you have more than one avionics unit per tech node. This may be because they should be in two different configs. If there is more that one for the same config, I would suggest averaging their values.

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