tspice

Getting started ​

tspice is an ESM-only TypeScript wrapper around the NAIF SPICE toolkit.

This guide uses the canonical spiceClients builder API.

Install ​

bash
pnpm add @rybosome/tspice
# or: npm i @rybosome/tspice

@rybosome/tspice is ESM-only. In CommonJS, use await import("@rybosome/tspice").

Quickstart (portable WASM) ​

This snippet:

  • uses the WASM backend (works in browsers and Node)
  • preloads a small kernel pack from kernels.tspice()
  • always disposes the client in a finally
ts
import { kernels, spiceClients } from "@rybosome/tspice";

const kernelPack = kernels.tspice().pick(
  "lsk/naif0012.tls",
  "pck/pck00011.tpc",
);

const { spice, dispose } = await spiceClients
  .withKernels(kernelPack)
  .toAsync({ backend: "wasm" });

try {
  const et = await spice.kit.utcToEt("2000 JAN 01 12:00:00");
  const j2000ToEarthFixed = await spice.kit.frameTransform("J2000", "IAU_EARTH", et);

  console.log(et, j2000ToEarthFixed.toRowMajor());
} finally {
  await dispose();
}

Kernel hosting note ​

kernels.naif() defaults to NAIF-hosted generic_kernels, and kernels.naif({ origin?, baseUrl?, pathBase? }) can build packs with relative URLs like kernels/naif/lsk/naif0012.tls.

That means:

  • in browsers, you typically serve the kernel files as static assets (often from /kernels/naif/... relative to your app base)
  • in Node, fetch() requires absolute URLs, so you must pass an absolute baseUrl (or use an absolute origin)
  • kernel URLs are just URLs; you can host them wherever you want

kernels.tspice() is a best-effort community catalog intended for quickstarts/demos (not production).

See /guide/kernels for details (including baseUrl and custom hosting).

Next ​