RocketPy Overview

Relevant source files

• .pylintrc
• CHANGELOG.md
• README.md
• docs/conf.py
• docs/matlab/Getting_Started.html
• docs/matlab/Getting_Started.m
• docs/matlab/Getting_Started.mlx
• docs/notebooks/getting_started.ipynb
• docs/notebooks/getting_started_colab.ipynb
• docs/user/installation.rst
• pyproject.toml
• rocketpy/mathutils/function.py
• rocketpy/mathutils/vector_matrix.py
• rocketpy/motors/tank_geometry.py
• rocketpy/rocket/rocket.py
• rocketpy/simulation/flight.py
• rocketpy/tools.py

RocketPy is a next-generation trajectory simulation solution for High-Power Rocketry. It provides a comprehensive 6-Degrees-of-Freedom (6-DOF) simulation environment, accounting for variable mass effects, sophisticated atmospheric modeling, and aerodynamic interactions.

System Architecture

RocketPy is designed around a modular, object-oriented architecture where physical components are represented by discrete Python classes. These objects are composed into a simulation pipeline that mimics the physical assembly and launch of a rocket.

Core Simulation Pipeline

The standard workflow involves the sequential instantiation and nesting of four primary classes:

1. Environment: Defines the physical world, including gravity, launch site coordinates, and atmospheric conditions rocketpy/simulation/flight.py47-49.
2. Motor: Defines the propulsion system, covering thrust curves, mass flow rates, and grain or tank geometries README.md48-51.
3. Rocket: Defines the vehicle airframe, including aerodynamic surfaces (fins, nose cones), recovery systems (parachutes), and mass distribution rocketpy/rocket/rocket.py36-150.
4. Flight: Orchestrates the numerical integration of the equations of motion (EOM) using advanced ODE solvers like LSODA rocketpy/simulation/flight.py30-102.

High-Level Class Relationship

The following diagram illustrates how code entities relate to the physical simulation concepts.

Simulation Entity Mapping

Sources: README.md23-66, rocketpy/simulation/flight.py42-63, rocketpy/rocket/rocket.py36-55

Key Capabilities

• 6-DOF Simulation: Rigorous treatment of mass variation effects and non-linear dynamics using the LSODA integrator README.md30-34, rocketpy/simulation/flight.py30-37.
• Atmospheric Modeling: Support for International Standard Atmosphere (ISA), custom Wyoming soundings, and real-time GFS/ECMWF/ERA5 forecasts and reanalysis README.md35-39, CHANGELOG.md49.
• Propulsion Variety: Specialized models for SolidMotor, LiquidMotor, and HybridMotor, including variable density fluids and complex tank geometries README.md48-51, CHANGELOG.md97-98.
• Stochastic Analysis: A robust Monte Carlo engine for dispersion analysis, global sensitivity analysis, and confidence interval estimation using bootstrapping README.md53-54, CHANGELOG.md64-65.
• Active Control & Sensors: Support for air brakes controllers with up to 8-parameter signatures and a suite of avionics sensors (Accelerometer, Gyroscope, Barometer, GNSS) CHANGELOG.md55-56, CHANGELOG.md98.

Code-to-System Mapping

This diagram maps specific subsystems to their primary implementation files and classes within the rocketpy/ directory.

Subsystem Code Map

Sources: rocketpy/mathutils/function.py54-150, rocketpy/simulation/flight.py42-170, rocketpy/rocket/rocket.py36-150

Deep Dives and Child Sections

To explore specific parts of the codebase in detail, refer to the following sections:

Getting Started & Installation

Covers the installation process via pip or conda, dependency management (core, env-analysis, monte-carlo) in pyproject.toml, and running your first simulation.

• Key Files: pyproject.toml42-71, docs/user/installation.rst1-160, docs/notebooks/getting_started.ipynb1-120.

Core Simulation Workflow

Provides a technical breakdown of the data flow between Environment, Motor, Rocket, and Flight. Explains how the 6-DOF equations are initialized and solved, including the management of flight phases and time nodes.

• Key Files: rocketpy/simulation/flight.py42-200, rocketpy/rocket/rocket.py36-150.

Further Subsystems

• Mathematical Utilities: The Function class rocketpy/mathutils/function.py54-150 is the backbone of the library, providing advanced interpolation (Akima, Spline, RBF) and algebraic operator overloading.
• Environment & Atmosphere: Advanced weather fetching and modeling, including support for NetCDF files and reanalysis data CHANGELOG.md70-71.
• Propulsion: Detailed modeling of solid grains, liquid tanks, and fluid dynamics with variable density CHANGELOG.md97-98.
• Aerodynamics: Modeling of NoseCone, Fins, Tail, and AirBrakes using Barrowman or custom lift/drag curves rocketpy/rocket/rocket.py15-26.
• Stochastic Analysis: Tools for uncertainty quantification, including MonteCarlo and confidence interval estimation CHANGELOG.md64-65.

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Sources: README.md23-86 rocketpy/simulation/flight.py30-170 rocketpy/rocket/rocket.py36-150 rocketpy/mathutils/function.py54-150 pyproject.toml1-71 CHANGELOG.md53-106 docs/user/installation.rst1-160