The core physics engine implementing all equations of motion and optimization.

Installation¶

uv sync --package apogee-physics

Dependencies¶

dependencies = [
    "jax",       # Automatic differentiation
    "diffrax",   # ODE solvers
    "ussa1976",  # Atmosphere model
]

Modules¶

Architecture¶

apogee_physics/
├── __init__.py
├── atmosphere.py    # USSA76 interpolation
├── dynamics.py      # ODE right-hand sides
├── simulate.py      # Hybrid system integration
├── shooting.py      # Levenberg-Marquardt solver
├── orbit.py         # Keplerian elements
├── trajectory.py    # Data serialization
├── types.py         # Dataclass definitions
└── calibration.py   # Drag models

Basic Usage¶

from apogee_physics import (
    AscentConfig,
    EarthParams,
    MissionParams,
    VehicleParams,
    NumericsParams,
    simulate_ascent,
    solve_circular_orbit,
)

# Configure simulation
config = AscentConfig(
    earth=EarthParams(r_e=6.371e6, mu=3.986e14, g0=9.80665),
    mission=MissionParams(h_target=200_000, payload_mass=5000),
    vehicle=vehicle_params,
    numerics=numerics_params,
)

# Run simulation
trajectory = simulate_ascent(config)

Equation References¶