🚀 Falcon 9 Booster Simulation

A high-fidelity 2D physics simulation of SpaceX's Falcon 9 first stage booster, featuring realistic rocket dynamics, autonomous landing algorithms, and real-time telemetry visualization.

🌐 Live Demo

Launch the Simulation →

Experience the complete Falcon 9 mission profile from liftoff to precision landing, all running in your browser with zero installation required.

✨ Key Features

Realistic Physics Simulation

• Newtonian mechanics with gravity, drag, and thrust modeling
• Mass dynamics including propellant consumption and stage separation
• Atmospheric effects with altitude-dependent air density
• Exhaust particle system with realistic plume physics

Autonomous Landing System

• Suicide burn algorithm for fuel-optimal descent
• Dynamic throttle control responding to altitude and velocity
• Grid fin simulation for atmospheric steering
• Precision landing targeting with real-time trajectory adjustment

Mission Phases

The simulation accurately models all 10 phases of a Falcon 9 booster mission:

1. Phase 0: Liftoff and initial ascent
2. Phase 1: Powered ascent with full thrust
3. Phase 2: Continued ascent toward stage separation
4. Phase 3: MECO (Main Engine Cutoff) and stage separation
5. Phase 4: Boostback burn initiation
6. Phase 5: Atmospheric re-entry
7. Phase 6: Grid fin deployment and aerodynamic guidance
8. Phase 7: Entry burn to reduce velocity
9. Phase 8: Landing burn with precision throttle control
10. Phase 9: Touchdown and landing leg deployment

Visual Features

• 10 phase-specific rocket sprites showing mission progression
• Chroma-keyed background images for launchpad and landing pad
• Dynamic camera system with 4 zoom levels (1.0x, 0.7x, 0.4x, 0.2x)
• Real-time exhaust effects with particle-based plume rendering
• Smooth animations at 60 FPS

Real-Time Telemetry

• Altitude tracking with live graphing
• Velocity monitoring (vertical and horizontal components)
• Acceleration vectors in real-time
• Fuel consumption and remaining propellant mass
• Throttle percentage display
• Mission phase indicators
• Interactive charts powered by Chart.js

🎮 Controls

• LAUNCH: Start the mission sequence
• RESET: Return to launchpad for another attempt
• ZOOM: Cycle through 4 camera zoom levels
• PAUSE/RESUME: Control simulation playback

🛠️ Technology Stack

• Frontend: HTML5 Canvas for rendering
• Physics Engine: Custom JavaScript implementation
• Visualization: Chart.js for telemetry graphs
• Deployment: GitHub Pages (static hosting)
• Development: Flask (local development server)

📊 Technical Specifications

• Initial Mass: ~25,600 kg (wet mass with propellant)
• Dry Mass: ~22,200 kg (empty booster)
• Thrust: Variable (0-100% throttle control)
• Fuel: RP-1/LOX (modeled as combined propellant)
• Engine: Merlin 1D cluster (9 engines)
• Max Velocity: ~2,000 m/s at MECO
• Landing Accuracy: <10 meters from target

🚀 Mission Profile

1. Liftoff: Full throttle ascent from Launch Complex 39A
2. Ascent: Powered flight to ~80 km altitude
3. MECO: Main engine cutoff and stage separation
4. Boostback: Flip maneuver and boostback burn
5. Coast: Ballistic trajectory through upper atmosphere
6. Re-entry: Grid fin deployment at ~70 km
7. Entry Burn: High-altitude deceleration burn
8. Landing Burn: Precision suicide burn for soft touchdown
9. Landing: Autonomous landing on drone ship or landing pad

🧪 Development

Local Development

# Clone the repository
git clone https://github.com/reversesingularity/falcon9sim.git
cd falcon9sim

# Run local Flask server
cd webapp
python app.py

# Open browser to http://localhost:5000

Project Structure

falcon9sim/
├── docs/                  # GitHub Pages deployment
│   ├── index.html        # Static HTML for web hosting
│   ├── js/               # JavaScript simulation engine
│   ├── css/              # Styling
│   └── images/           # Rocket sprites and backgrounds
├── webapp/               # Flask development version
│   ├── app.py           # Flask server
│   ├── templates/       # HTML templates
│   └── static/          # Static assets
├── scripts/             # Trajectory optimization scripts
│   ├── falcon9_trajectory_optimization.py
│   └── brachistochrone_dymos.py
└── aircraft/            # JSBSim flight dynamics models
    └── Falcon9Booster/  # Falcon 9 XML configuration

🔬 Physics & Algorithms

Suicide Burn Algorithm

The simulation implements a fuel-optimal landing algorithm that calculates the precise moment to initiate the final landing burn:

landing_burn_start = sqrt(2 * altitude / (thrust/mass - g))

This ensures the rocket reaches zero velocity exactly at ground level, minimizing fuel consumption.

Atmospheric Model

Air density decreases exponentially with altitude:

ρ(h) = ρ₀ * exp(-h / H)

where H = 8,500m (scale height)

Drag Force

F_drag = 0.5 * ρ * v² * C_d * A

📈 Trajectory Optimization

The scripts/ directory contains advanced trajectory optimization tools using:

• OpenMDAO: Multidisciplinary optimization framework
• Dymos: Dynamic optimization library
• pyOptSparse: Sparse optimization algorithms

These tools can generate optimal ascent and descent trajectories for the Falcon 9 booster.

🎯 Future Enhancements

• 3D visualization mode
• Multiple landing sites (OCISLY, JRTI, LZ-1, LZ-2)
• Weather conditions (wind, turbulence)
• Failure modes and emergency abort scenarios
• Replay system with saved missions
• Leaderboard for landing accuracy
• VR/AR support

📝 License

This project is open source and available for educational and demonstration purposes.

🙏 Acknowledgments

• SpaceX for inspiring this simulation
• The aerospace engineering community
• JSBSim flight dynamics engine
• NASA for trajectory optimization tools

📧 Contact

Created by @reversesingularity

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Ready for liftoff? Try the simulation now!