AutoLanding — Spaceflight Simulator Mod

Automatic rocket landing autopilot for Spaceflight Simulator (Steam/PC).

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Features

• 3-phase state machine: Coast → Braking → Final approach
• PID velocity control with feedforward hover compensation
• Reads local gravity in real time — works on the Moon, Mars, or custom planets
• Corrects horizontal drift automatically
• Emergency governor prevents suicide burns at high speed
• Draggable HUD overlay with real-time telemetry
• Compatible with any rocket with TWR ≥ ~1.1

Requirements

• BepInEx 5.4.x installed in your SFS game folder
• Spaceflight Simulator (Steam, PC)

Installation

1. Install BepInEx 5.4.x if you haven't already — follow the BepInEx installation guide
2. Download AutoLanding.zip from the Releases page and extract it
3. Copy AutoLanding.dll to:

   <SFS game folder>\BepInEx\plugins\AutoLanding.dll
   

4. Launch the game — BepInEx will load the mod automatically

Usage

Key	Action
F8	Toggle autopilot on / off

Once activated, a HUD window appears in the top-left corner showing:

Field	Description
Estado	Current phase: Coast / Braking / Final / Landed
Altitude	Height above terrain (m)
VSpeed	Vertical speed (m/s, negative = descending)
HSpeed	Horizontal speed (m/s)
Throttle	Current throttle %
BurnAlt	Calculated braking altitude (m)
VProfile	Maximum safe speed at current altitude (m/s)
TWR	Thrust-to-weight ratio

Tips:

• Activate during a suborbital arc with engines off for best results
• Works best with TWR ≥ 1.2; lower TWR increases braking distance
• The rocket must be pointing roughly upward on activation

How it works

The autopilot runs a three-phase algorithm:

Phase	Trigger	Behavior
Coast	h > burnAlt × 1.35	Engines off; attitude controller keeps rocket vertical
Braking	h ≤ burnAlt × 1.35	Main deceleration burn; velocity target = min(0.85 × vProfile, 0.32 × √(2gh))
Final	h < 25 m	Smooth linear ramp from braking speed down to touchdown at 0.35 m/s

An emergency governor overrides to full throttle if the burn margin drops below 85% or current speed reaches 90% of the safe velocity profile.

Building from Source

1. Clone the repo
2. Copy Directory.Build.props.example → Directory.Build.props
3. Edit Directory.Build.props — set <SFSGamePath> to your SFS game folder
4. Build and deploy:

   .\deploy.ps1

   Or just build without deploying:

   dotnet build -c Release AutoLanding
   

License

MIT