VesselPlanner for KSP1

VesselPlanner is a planning, staging, mission-design, delta-v reference, part-selection, and flight-telemetry mod for Kerbal Space Program 1.12.x.

It can analyze an existing stage, size a new stage, compare engine choices, find compatible tank combinations, build and save complete multi-stage vessel plans, create mission plans, browse planet-pack delta-v data, place selected parts into the KSP editor, and record/export flight telemetry.

For detailed change history, see CHANGELOG.md.

Contents

• Requirements
• Installation
• Editor modes
• Analyze Existing
• Planning
• Mission Planner
• Stage-By-Stage
• Delta-V Table
• Engine and tank planning
• Part images and editor placement
• Delta-v tables and planet packs
• Settings
• Flight Data
• Saved data and exports
• Documentation
• Calculation notes
• Known limits
• Building from source
• License

Requirements

VesselPlanner requires:

• Kerbal Space Program 1.12.x
• ToolbarController
• ClickThroughBlocker

The dependency folders are normally:

GameData/001_ToolbarControl/
GameData/000_ClickThroughBlocker/

Installation

1. Remove any older GameData/EngineStagePlanner installation so KSP does not load both assemblies.
2. Copy the VesselPlanner folder into:

text KSP_ROOT/GameData/VesselPlanner/

1. Verify that the plugin DLL is located at:

text KSP_ROOT/GameData/VesselPlanner/Plugins/VesselPlanner.dll

1. Verify that the following are present:

text GameData/VesselPlanner/VesselPlanner.version GameData/VesselPlanner/PluginData/Textures/ GameData/VesselPlanner/PluginData/DeltaVTables/

1. Start KSP.

VesselPlanner can migrate older EngineStagePlanner settings, Stage-By-Stage plans, and stored flight maxima when equivalent VesselPlanner files do not already exist.

Opening VesselPlanner

VesselPlanner uses one ToolbarController button in both the editor and flight scenes.

• In the VAB/SPH, the button opens the main VesselPlanner editor window.
• In flight, the button opens the Flight Data window.

The main editor window is horizontally resizable from approximately 1150 to 1850 pixels, and the selected width is remembered. Candidate-table headers scroll horizontally with the rows so columns stay aligned.

The editor modes are grouped approximately as:

Mission Planner | Stage-By-Stage    Analyze Existing | Planning    Delta-V Table

Editor modes

Analyze Existing

Use Analyze Existing when a stage already exists on the current craft and you want to understand it or compare replacement engines against the real stage.

Features include:

• Select a stage by number, Pick Stage, or KSP's staging list.
• Read current stage mass, payload, propellant, tank capacity, resources, engine mass, burn time, and current engines.
• Use KSP VesselDeltaV / DeltaVStageInfo mass boundaries when available.
• Evaluate replacement engines using the propellant currently loaded in the stage.
• Remove installed engine dry mass before adding candidate engine mass.
• Preserve unrelated resources as carried mass when a candidate cannot burn them.
• Honor installed engine thrust limiters when describing the current configuration.
• Simulate the selected body and altitude.
• Set minimum TWR and maximum engine count.
• Include or exclude solid-fuel, air-breathing, and electric-propellant engines.
• Ignore monopropellant when desired.
• Simulate all engines when appropriate.
• Optionally match the stage bulkhead size.
• Filter and exclude engines by comma-separated text terms.
• Sort the candidate engine table by any displayed column.
• View a Selected Engine detail pane.
• Add a selected engine directly to the KSP editor cursor.
• Resize the candidate/detail panes and save the pane size.

Planning

Use Planning to design a stage that does not exist yet or to size a stage independently from the current craft.

Planning supports:

• Target delta-v.
• Vacuum or Atmosphere target basis.
• Minimum TWR.
• Typed payload mass or payload taken from the craft above the selected stage.
• Body and atmospheric altitude selection.
• Maximum engine count.
• Configurable estimated tank dry/fuel mass ratio.
• Solid-fuel, air-breathing, and electric-propellant engine-class controls.
• Engine include/exclude text filters.
• Optional bulkhead-size matching.
• Sortable candidate engine results.
• Resizable engine, Selected Engine, and tank panes.
• Actual tank-set selection after an engine is chosen.

Optimization goals include:

• Lowest Stage Mass
• Lowest Propellant Mass
• Lowest Cost
• Shortest Burn
• Highest TWR
• Highest Isp

Planning's Vacuum and Atmosphere target modes behave differently:

• Vacuum sizes the stage to the requested vacuum delta-v. Body/altitude changes affect atmospheric performance displays but do not resize the already-sized stage.
• Atmosphere sizes the stage at the selected body and altitude, so changing the environment can change propellant, tank mass, wet mass, engine count, and the resulting stage solution.

Mission Planner

Mission Planner builds an ordered sequence of mission steps. A step can be one of two types:

• Engines & Tanks — maneuver/body/delta-v/ASL-VAC information.
• Subassemblies — one or more saved KSP subassemblies with Count and Decoupler options.

Mission Planner supports:

• Named mission plans.
• Add, edit, insert, delete, and reorder operations.
• Human-readable maneuver names.
• ASL/VAC basis selection.
• Body history tracking across mission steps.
• Automatic delta-v suggestions from the active delta-v table.
• Transfer-source handling for interplanetary steps.
• Transfer-planner clipboard import where supported.
• Return-from-moon calculations using the active table.
• Saved KSP subassembly selection.
• Per-subassembly count and decoupler settings.
• Save/load of mission plans.
• Direct integration with Stage-By-Stage planning.

Mission steps are intentionally either propulsion steps or subassembly steps; a single step does not mix both types.

Stage-By-Stage

Stage-By-Stage lets you design an entire vessel from the payload downward before assembling it in the KSP editor.

Capabilities include:

• Create a named vessel plan.
• Start from the current craft wet mass or a typed payload.
• Design upper stages first and automatically carry their mass into later/lower stages.
• Create Engines & Tanks stages using the normal delta-v/TWR solver.
• Create Subassemblies stages from saved KSP subassemblies.
• Link a Stage-By-Stage plan to a saved Mission Planner mission.
• Click mission steps to create or reopen matching stages.
• Carry mission-step body/environment information into stage calculations.
• Set target delta-v, ASL/VAC basis, TWR, engine limits, cargo mass, and stage decouplers.
• Restrict engine and tank choices by KSP bulkhead profile.
• Add mixed tank sets to a stage.
• Track counted subassemblies and per-copy decouplers.
• Edit completed stages and automatically update mass carried by later stages.
• Save and load work-in-progress plans.
• Finalize a plan into a practical build list.
• Use Add actions in the finalized build list to select planned engines/tanks for normal KSP editor placement.

Delta-V Table

The Delta-V Table page reads the active planet-pack CSV and shows it as an expandable body tree.

Features include:

• Solar-orbiting bodies as top-level rows.
• Expand/collapse moon systems by clicking the parent body.
• Support for nested moon systems such as Urlum -> Wal -> Tal in OPM.
• Fixed columns for:
• Body
• dV to low orbit
• Ejection
• Capture
• Plane Change
• Total
• Landing
• Ascent
• Zero or unavailable values are left blank.
• Moon indentation is confined to the Body column so value columns remain aligned.
• Every displayed numeric value is clickable.
• Clicking a value copies the numeric value only to the system clipboard.
• A status line at the bottom confirms the copied value.

For route values:

• planets use the home-body -> planet route
• moons use the immediate parent -> moon route
• nested moons use the immediate parent -> child route

Engine and tank planning

Candidate engine table

Planning and Analyze Existing share a sortable candidate engine table. Available columns include:

• Engine
• Engine count
• Engine mass
• Stage Wet mass
• Start Mass
• Atmospheric delta-v
• Vacuum delta-v
• ASL thrust per engine
• Vacuum thrust per engine
• Cost Efficiency
• TWR
• Max TWR
• ASL/Vacuum Isp
• Burn time
• Fuel/propellant summary
• Bulkhead profile
• Add action

Individual columns can be enabled or disabled in Settings.

Candidates come from KSP's loaded part database after editor ExcludeFilters are applied. The currently selected KSP editor category is not used as a VesselPlanner candidate filter.

Engine filtering

Engine lists support separate Filter and Exclude fields.

• Each field accepts comma-separated terms.
• Filter terms use OR matching.
• Any matching Exclude term removes the engine.
• Persistence of the four engine/tank include/exclude fields can be controlled independently in Settings.

Tank planning

After an engine is selected, VesselPlanner finds compatible storage parts for its propellant requirements.

Tank planning supports:

• One, two, or three different tank types in one suggested set.
• Counts for each tank type.
• Total tank count.
• Total tank dry mass.
• Excess capacity.
• Supplied resource capacity.
• Shared KSP bulkhead profile.
• Tank include/exclude text filters.
• Part thumbnails for every tank type in a set.
• Direct part placement in normal Planning.
• Add to Stage behavior while Stage-By-Stage is capturing an Engines & Tanks stage.

Tank suggestions require storage parts with both top and bottom attach nodes. Radial or one-ended tanks are intentionally excluded from this list.

Part images and editor placement

VesselPlanner displays KSP part thumbnails in:

• Planning engine candidates
• Analyze Existing engine candidates
• Analyze Existing Current engines
• Planning tank-set rows
• Stage-By-Stage engine/tank build-list rows

Part images use the exact loaded AvailablePart.partUrl when available, which helps distinguish mod parts that share the same internal name.

Hovering over a thumbnail shows a larger rotating preview generated from KSP's editor icon prefab.

Configurable part-image controls include:

• ZoomFactor for icons
• ZoomFactor for Rotating Images
• Camera Yaw Degrees
• Camera Pitch Degrees
• RotatingPreviewSize
• Degrees per frame
• Rotating Image Background

Changing these settings invalidates the relevant image cache so new thumbnails/previews use the new configuration.

VesselPlanner uses KSP's normal editor part-selection path for placement. Engine and tank Add actions select the corresponding part on the KSP editor cursor. Analyze Existing and Planning each have independent settings controlling whether the VesselPlanner window closes after a successful Add.

Delta-v tables and planet packs

Mission Planner and Delta-V Table share CSV files under:

GameData/VesselPlanner/PluginData/DeltaVTables/

The schema is:

Origin,Destination,dV_to_low_orbit,ejection_dV,capture_dV,transfer_to_low_orbit_dV,total_capture_dV,dV_low_orbit_to_surface,ascent_dV,plane_change_dV,parent,isMoon,order

VesselPlanner uses PlanetPackHeuristics to detect the active system and select a matching table where possible.

Bundled starter tables include:

• Stock
• OPM — Outer Planets Mod
• JNSQ
• GPP — Galileo's Planet Pack
• RSS — Real Solar System

The CSV files are editable. You can replace or extend rows for your preferred delta-v map as long as the schema and body hierarchy are preserved.

The bundled OPM table includes Sarnus, Urlum, Neidon, Plock, their mapped moons, Eeloo under Sarnus, and the nested Wal -> Tal relationship.

Settings

Editor settings are stored in:

GameData/VesselPlanner/PluginData/VesselPlannerSettings.cfg

Engine Columns

Show or hide individual columns in the candidate-engine table. Show All and Hide All provide quick presets.

Analyze Existing

Configure which informational lines are visible in the Existing Stage pane and whether the window closes after a successful Add.

Planning

Configure whether Planning closes after a successful engine/tank Add action.

Filters

Four independent persistence settings control whether these fields are restored next session:

• engine Filter
• engine Exclude
• tank Filter
• tank Exclude

Appearance

Appearance settings include:

• KSP skin or Alternate/Unity skin.
• Solid backgrounds for VesselPlanner editor windows.
• Master Show tooltips toggle.
• Part-image camera/zoom/render settings.
• Rotating-preview background.
• Reset image settings.
• Saved Planning/Analyze pane sizes.
• Reset pane sizes.

Tooltips include help for the Part Images numeric fields/sliders and Mission Planner controls.

Flight Data

In flight, the toolbar button opens the Flight Data graph window.

Window and recording controls

• Minimum Flight Data window width: 1000 pixels.
• Horizontal resize support.
• Start Plotting / Stop Plotting.
• Start at Launch / Launch Armed.
• Reset samples and stage markers.
• Configurable Sample Interval.
• Sample count display.
• Settings button at the top-right next to the close button.
• Sampling pauses while KSP is paused.

Start at Launch can be armed while the vessel is in PRELAUNCH. When the vessel leaves PRELAUNCH, VesselPlanner clears the existing graph and begins recording automatically.

Recorded data

VesselPlanner can record:

• Surface velocity
• Orbital velocity
• Vertical speed
• Acceleration
• G-force
• Altitude ASL
• Altitude above terrain/surface
• Dynamic pressure (q)
• Vehicle mass
• Angle of attack
• Every resource currently carried by the active vessel
• Stock ModuleEnviroSensor outputs found on the vessel

All available sources are recorded while plotting even if they are not currently visible, so display selections can be changed without losing already-collected samples.

Graph behavior

• Plotted-sensor legend with color, current value, maximum value, and units.
• Scrolling time-series graph; after the visible area fills, traces, vertical time-grid lines, elapsed-time labels, and stage markers move left together as new samples arrive.
• Configurable time labels: every line, every other line, or every third line.
• Stage activations shown as dashed vertical markers.
• Configurable altitude chart top with Body Default.
• Persistent per-vessel non-altitude maxima across launches/reverts.
• Selectable left/right axis annotations per series.
• Separate Flight Settings window.
• Optional solid Flight Data background.

Flight Settings

Flight Settings can control:

• Altitude chart top and Body Default.
• Solid Flight Data background.
• Time-label frequency.
• CSV export folder.
• PNG export folder.
• Clear Max Values for Vessel.
• Plot selection.
• Max display.
• Units.
• Axis side.
• All/None controls for Flight data, Ship resources, and Sensor outputs.

Export

At the bottom of the Flight Data window:

• the CSV path is shown with Export CSV on the same row
• the PNG path is shown with Export PNG on the same row

Default locations:

CSV: GameData/VesselPlanner/PluginData/CSV
PNG: KSP_ROOT/Screenshots

CSV export writes the selected plotted series. PNG export saves the currently visible graph, including graph-rendered time labels and axis annotations.

Saved data and exports

Typical persistent data lives under:

GameData/VesselPlanner/PluginData/

Important files and folders include:

• VesselPlannerSettings.cfg — editor and Flight Data settings
• DeltaVTables/*.csv — Mission Planner and Delta-V Table data
• MissionPlans/*.cfg — saved Mission Planner missions
• Plans/*.cfg — saved Stage-By-Stage plans
• FlightSensorMaxima.tsv — per-vessel historical graph maxima
• CSV/ — default CSV export folder

Additional configuration files include:

• GameData/VesselPlanner/BulkheadProfiles.cfg
• GameData/VesselPlanner/decouplerMasses.cfg
• GameData/VesselPlanner/VesselPlanner.version

PNG exports default to:

KSP_ROOT/Screenshots

Documentation

The source package includes a full manual and focused tutorials under Manual/:

• VesselPlanner-Manual.docx
• VesselPlanner-Analyze-Existing-Tutorial.docx
• VesselPlanner-Planning-Tutorial.docx
• VesselPlanner-Mission-Planner-Tutorial.docx
• VesselPlanner-Stage-by-Stage-Tutorial.docx

A Markdown version of the main manual is also included as:

VesselPlanner-Manual.md

Calculation notes

TWR and engine performance

• TWR uses the selected body's surface gravity.
• Vacuum thrust comes from loaded ModuleEngines / ModuleEnginesFX data.
• Atmospheric thrust follows the engine atmosphere curve and available KSP flow calculations.
• Candidate TWR uses total cluster thrust.
• ASL/Vac thrust columns show thrust per engine.

Stage mass

Analyze Existing prefers KSP's own VesselDeltaV / DeltaVStageInfo stage mass boundaries when available.

Planning solves a new stage iteratively because required propellant affects estimated tank mass, which changes the total mass the propellant must accelerate.

Before a real tank set is selected, estimated tank dry mass is calculated from the configured tank dry/fuel mass ratio.

Burn time

VesselPlanner derives mass flow from thrust and Isp and uses KSP standard gravity (9.80665 m/s²). Analyze Existing calculates burn duration from the propellant mixture the candidate can actually consume.

Resources

VesselPlanner reads the propellant list from each loaded engine module rather than assuming LiquidFuel/Oxidizer. Mass-bearing propellants drive the rocket equation; auxiliary ignoreForIsp resources can still be shown as requirements. Resource volume uses KSP PartResourceDefinition.volume where available.

Known limits

VesselPlanner is a planning and analysis tool, not a complete replacement for KSP's in-flight fuel-flow simulation.

The following are not fully modeled:

• Dynamic RealFuels/B9/MFT-style tank reconfiguration after prefab loading.
• Complete jet intake and velocity-curve flight-state simulation beyond the loaded engine/pressure behavior available to the solver.
• Arbitrary third-party engine-variant systems outside loaded ModuleEngines / ModuleEnginesFX.
• Full MechJeb-style crossfeed/asparagus/drop-tank fuel-flow simulation for every modded arrangement.

For unusual modded fuel-flow systems, Planning with a manually entered payload can be more reliable than depending on a complex editor branch scan.

Building from source

The project is a C# library targeting:

• .NET Framework 4.8
• C# 7.3

The project references KSP's managed assemblies plus ToolbarController and ClickThroughBlocker.

The Visual Studio project is:

VesselPlanner/VesselPlanner.csproj

The solution is:

VesselPlanner.sln

The project includes build/deploy helpers for copying the DLL, icons, version file, delta-v tables, bulkhead configuration, and decoupler configuration into a KSP development install.

License

See License.md for the project license.