---
id: spiceypy
version: "8.2.0"
license: MIT
license_treatment: permissive
maintenance: active
---

# spiceypy — A Python Wrapper for the NAIF CSPICE Toolkit

License: permissive · Maintenance: active · Downloads: 210.8K/mo

## What it is and what it does

SpiceyPy is a Python wrapper around the NAIF SPICE Toolkit, a C library developed by NASA's Jet Propulsion Laboratory for computing positions, orientations, and geometric relationships of celestial bodies and spacecraft. It uses ctypes and Cython to expose SPICE functions to Python, allowing scientists and engineers to query ephemeris data, transform between coordinate frames, and compute lighting geometry without writing C code.

The package is production-stable (Development Status 5) and actively maintained. It depends only on numpy and requires Python 3.10 or later. Precompiled wheels cover modern Linux, macOS, and Windows architectures, reducing installation friction. The NAIF now distributes official Python lessons using SpiceyPy, signaling institutional support. Users must obtain and load SPICE kernel files (ephemeris, leap-second, and planetary constants data) separately; the package itself is a compute interface, not a data distribution.

Use it for:

- Compute spacecraft position and velocity at a given time for mission planning or analysis.
- Transform coordinates between spacecraft, planetary, and inertial reference frames.
- Calculate lighting geometry (e.g., solar illumination angles) for instrument planning.
- Query planetary body positions and orientations for orbital mechanics simulations.
- Validate or supplement trajectory data in multi-body dynamics software.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

SpiceyPy wraps the NAIF C SPICE Toolkit to compute Solar System geometry, ephemeris, and coordinate transformations for planetary science applications.

Yes. SpiceyPy is production-stable, actively maintained, has no known vulnerabilities, and is the standard Python interface to SPICE in the planetary science community. Install friction is moderate due to compiled dependencies, but precompiled wheels for modern Python versions (3.10–3.13) and common architectures minimize friction. The MIT license is permissive. Install if you need Solar System geometry or ephemeris calculations; skip if you do not work in planetary science or spacecraft operations.

## Install

pip install spiceypy
uv add spiceypy
poetry add spiceypy

## Installing spiceypy

Before you install: Precompiled wheels available for Python 3.10–3.13 across Linux (x86_64, aarch64), macOS (x86_64, arm64), and Windows; medium install friction reflects the compiled C dependency. Actively maintained with a release 21 days old and recent commits.

License in practice: MIT license permits commercial and private use with minimal restrictions; suitable for most projects.

Quickstart:

pip install spiceypy
import spiceypy as sp
sp.furnsh('path/to/kernel.bsp')
position, _ = sp.spkgeo(target_id, et, frame, observer_id)

SPICE kernel files (.bsp, .tls, .pck) must be obtained separately from NAIF and furnished before most computations.

Verify before relying:

- Whether kernel data files are included or must be downloaded separately from NAIF.
- Performance characteristics for large-scale ephemeris queries or real-time applications.
- Compatibility with concurrent or async workflows.

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: medium
- Maintenance: active
- Downloads: 210.8K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

solar system geometry calculations, ephemeris and trajectory data, spacecraft position and orientation, coordinate frame transformations, planetary science toolkit, spice toolkit python wrapper, naif cspice interface, space-mission-planning, ephemeris-toolkit, coordinate-transforms

[View on SkillFed](https://skillfed.io/packages/spiceypy) · [View on PyPI](https://pypi.org/project/spiceypy/)