spice-kernel-db

Browse, get, and manage SPICE kernels and metakernels across NASA and ESA mission archives.

⚠️ CRITICAL: Update to v0.10.0 or later. Versions before 0.10.0 contained a fuzzy filename matching bug that could silently create symlinks between completely different SPICE kernel files, causing silent scientific data corruption — SPICE loads valid but wrong data with no errors. All users who used spice-kernel-db get or spice-kernel-db update are affected, regardless of the dedup setting — the symlink creation code did not honor the per-mission dedup flag (also fixed in 0.10.0). Users who only used scan and resolve are not affected. After updating, remove all symlinks in your kernel directories and re-run spice-kernel-db update. See CHANGELOG.md for recovery steps.

What this tool does

1. Mission setup: Configure missions from NASA NAIF or ESA SPICE servers with an interactive dialog.

2. Browse & get: Browse available metakernels for a mission, then get one — the tool downloads all missing kernels automatically and makes the metakernel ready to use locally.

3. Metakernel rewriting: Rewrites .tm files for local use with minimal edits — only PATH_VALUES is changed, everything else stays identical to the original. A symlink tree bridges the gap between where the metakernel expects files and where they actually live on disk.

4. Deduplication (optional): Identifies identical kernel files across missions using SHA-256 hashing and replaces duplicates with symlinks. Per-mission opt-in — you can deduplicate some missions while keeping others untouched.

Documentation

Full documentation is at michaelaye.github.io/spice-kernel-db and built with Quarto.

Installation

pip install spice-kernel-db

Or with conda:

conda install -c michaelaye spice-kernel-db

Or from source:

git clone https://github.com/michaelaye/spice-kernel-db
cd spice-kernel-db
pip install -e ".[dev]"

Quick start

Set up a mission

spice-kernel-db mission add

Interactive dialog: choose a server (NASA NAIF / ESA SPICE) → pick a mission from the list → configure deduplication preference.

Browse available metakernels

spice-kernel-db browse JUICE

Shows all .tm files in the mission's remote mk/ directory, grouped by base name with version counts.

Get a metakernel

spice-kernel-db get juice_ops.tm

Downloads the metakernel, checks which kernels you already have, downloads the missing ones in parallel, and creates symlinks so the .tm file works immediately.

Use with spiceypy

import spiceypy as spice
from spice_kernel_db import KernelDB

db = KernelDB()
mks = db.list_metakernels(mission="JUICE")
spice.furnsh(mks[0]["mk_path"])

Python API

from spice_kernel_db import KernelDB

db = KernelDB()

# Browse remote metakernels
db.browse_remote_metakernels(
    "https://naif.jpl.nasa.gov/pub/naif/JUICE/kernels/mk/",
    mission="JUICE",
)

# Get a metakernel (downloads missing kernels automatically)
db.get_metakernel(
    "https://naif.jpl.nasa.gov/pub/naif/JUICE/kernels/mk/juice_ops.tm",
    mission="JUICE",
)

# Optionally deduplicate across missions
db.deduplicate_with_symlinks(dry_run=True)   # preview
db.deduplicate_with_symlinks(dry_run=False)  # execute

Supported servers

Server	URL
NASA NAIF	https://naif.jpl.nasa.gov/pub/naif/
ESA SPICE	https://spiftp.esac.esa.int/data/SPICE/

Both use the same <server>/<MISSION>/kernels/mk/ directory structure.

Dependencies

• Python >= 3.11
• DuckDB >= 1.0
• rich >= 13.0

License

MIT