Kinetica

Kinetica is a modular Python-based rocket and mission simulation project focused on launch vehicle design, ascent analysis, orbital insertion, and simplified 3D mission planning.

The project started as a 2D ascent simulator and is evolving into a more complete mission analysis tool with:

• multi-stage launch vehicles
• 2D and 3D trajectory simulation
• simplified multi-body dynamics
• launch site modeling
• atmospheric drag
• stage separation
• mission phases such as burn, coast, target orbit, and SOI transitions
• interactive Streamlit dashboard for mission design and visualization

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Features

Launch vehicle modeling

• Configurable multi-stage rockets
• Dry mass, propellant mass, thrust, Isp, and diameter per stage
• Payload mass and drag coefficient support
• Preset rockets for quick testing

2D ascent simulation

• Pitch program support
• RK4 integration
• Gravity and aerodynamic drag
• Stage depletion and staging
• Orbital element estimation from ascent result

3D mission simulation

• 3D state propagation
• Simplified n-body gravity
• Sphere of influence detection
• Rotating launch bodies
• Launch site initial velocity from planetary rotation
• Basic atmospheric drag model
• Stage-by-stage propellant consumption
• Mission phases:
  • burn
  • coast
  • target_orbit
  • soi_change

Interactive dashboard

• Streamlit-based mission designer
• Rocket stage editor
• Mission phase editor
• Launch site configuration
• Earth-centered, Moon-centered, cislunar, and global trajectory views
• Event visualization
• English / Spanish UI support

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Project structure

rocket-sim/
├─ src/
│  └─ Kinetica/
│     ├─ config/
│     │  ├─ rockets.py
│     │  └─ celestial_systems.py
│     ├─ models/
│     │  ├─ rocket.py
│     │  ├─ stage.py
│     │  ├─ planet.py
│     │  ├─ celestial_body.py
│     │  └─ mission.py
│     ├─ simulation/
│     │  ├─ trajectory2d.py
│     │  └─ mission3d.py
│     ├─ ui/
│     │  ├─ cli.py
│     │  ├─ dashboard.py
│     │  └─ i18n.py
│     └─ main.py
└─ README.md

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Requirements

Recommended Python version

• Python 3.10+

Install dependencies with:

pip install -r requirements.txt

Typical dependencies include:

numpy
matplotlib
streamlit
plotly

If you are using a virtual environment on Windows:

.venv\Scripts\python.exe -m pip install -r requirements.txt

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Running the project

CLI mode

python src/Kinetica/main.py --ui cli

Streamlit dashboard

streamlit run src/Kinetica/ui/dashboard.py

If import resolution fails because of the src/ layout, make sure the project is run from the repository root and that src is available in PYTHONPATH, or keep the existing path bootstrap code inside the app files.

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##Dashboard overview

The dashboard allows you to:

• select a rocket preset
• edit stage parameters
• configure payload and drag coefficien
• define launch latitude, longitude, altitude, and azimuth
• choose a mission profile or build a custom one
• simulate 3D missions and inspect:
  • altitude
  • velocity
  • mass
  • dominant body
  • Earth-centered trajectories
  • Moon-centered trajectorie
  • Earth-Moon transfer view
  • global 3D trajectory
  • mission events

The interface supports both English and Spanish.

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Mission model

Mission planning is phase-based.

Supported phase types:

burn

A powered phase using thrust and Isp, with configurable direction modes such as:

• prograde
• retrograd
• radial_out
• radial_in
• normal
• antinormal

coast

A ballistic propagation phase with no thrust.

target_orbit

A simplified powered phase that attempts to reach a target periapsis and apoapsis around the currently dominant body.

soi_change

A waiting or propagation phase used to continue the mission until the spacecraft enters the sphere of influence (SOI) of a target body.

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Physics model

Kinetica currently uses a simplified but useful physical model:

• RK4 numerical integration
• Newtonian gravity
• simplified multi-body superposition
• SOI-based mission interpretation
• exponential atmosphere model
• drag based on vehicle frontal area and drag coefficient
• planetary rotation for launch-site initial velocity
• real stage propellant depletion and dry-mass separation

This makes the simulator useful for prototyping and educational mission analysis, but it is not yet a high-fidelity astrodynamics tool.

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Current limitations

Kinetica is still under active development. Current limitations include:

• no Lambert solver
• no optimized translunar injection guidance
• no high-fidelity patched conics
• no precise gravity assist targeting
• no non-spherical gravity model
• no detailed engine throttling or restart logic
• no advanced ascent guidance or gravity turn autopilot
• atmosphere is simplified
• celestial body orientations are simplified
• no full ECI/ECEF reference frame system yet

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Notes

This project is intended for experimentation, learning, and iterative development.

Results should be interpreted as approximate unless validated against a higher-fidelity reference tool.

License MIT License Author

Created by Alfonso Fernández