brahe

name	brahe
description	Python astrodynamics and satellite dynamics with Brahe. Use for orbital propagation, coordinate transformations, access computation, attitude representations, trajectories, space weather, datasets, and visualization. Triggered by brahe, orbital mechanics, satellite propagation, astrodynamics, TLE, SGP4, Keplerian orbits, ground track, or access windows.

Brahe Skill

Curated documentation and runnable examples for the Brahe Python library.

Quick Start

To do something fun like calculating the orbital-period of a satellite in low Earth orbit:

import brahe as bh

# Define the semi-major axis of a low Earth orbit (in meters)
a = bh.constants.R_EARTH + 400e3 # 400 km altitude

# Calculate the orbital period
T = bh.orbital_period(a)

print(f"Orbital Period: {T / 60:.2f} minutes")
# Outputs:
# Orbital Period: 92.56 minutes

or find when the ISS will next pass overhead:

import brahe as bh

bh.initialize_eop()

# Download ISS TLE and create a propagator
client = bh.celestrak.CelestrakClient()
iss = client.get_sgp_propagator(catnr=25544, step_size=60.0)

# Propagate for 24 hours
epoch_start = iss.epoch
epoch_end = epoch_start + 24 * 3600.0
iss.propagate_to(epoch_end)

# Compute upcoming passes over San Francisco
passes = bh.location_accesses(
    bh.PointLocation(-122.4194, 37.7749, 0.0),  # San Francisco
    iss,
    epoch_start,
    epoch_end,
    bh.ElevationConstraint(min_elevation_deg=10.0),
)
print(f"Number of passes in next 24 hours: {len(passes)}")
# Example Output: Number of passes in next 24 hours: 5

Module Map

See more examples and documents on how to use brahe:

Topic	Reference
Time & EOP	docs/learn/time/index.md, docs/learn/eop/index.md
Coordinates	docs/learn/coordinates/index.md
Orbits	docs/learn/orbits/index.md
Propagation	docs/learn/orbit_propagation/index.md, docs/learn/orbit_propagation/numerical_propagation/index.md
Dynamics	docs/learn/orbital_dynamics/index.md
Space Weather	docs/learn/space_weather/index.md
Trajectories	docs/learn/trajectories/index.md
Access	docs/learn/access_computation/index.md
Datasets	docs/learn/datasets/index.md
Plots	docs/learn/plots/index.md
Attitude	docs/learn/attitude_representations/index.md
Relative Motion	docs/learn/relative_motion/index.md

Common Patterns

See docs/learn/index.md for the full user guide overview. Linked example guides stay under docs/examples/, API docs under docs/library_api/, and runnable helpers under examples/ and plots/learn/.

Official Documentation

• User Guide: https://duncaneddy.github.io/brahe/latest/learn/
• Python API Reference: https://duncaneddy.github.io/brahe/latest/library_api/
• Source Code: https://github.com/duncaneddy/brahe