Skip to main content

Migrating

v6 to v7​

Breaking changes​

  • Dropped support for Node.js of versions not listed here:

    • 20.19 and above
    • 22.13 and above
    • Major version 24 and newer

  • Dropped support for non-evergreen browsers.

  • Dropped AMD, CJS and minified builds. The library is now ESM only. If you're on Node.js higher than listed above and use CJS, this doesn't affect you, because all current LTS Node.js support require(ESM) and this library works with that.

  • sunPos() now returns EciVec3<AU> as its rsun output, instead of number[]:

    // before
    const {
      rsun: [x, y, z], rtasc, decl
    } = sunPos(jday);
    // after
    const {
      rsun: { x, y, z }, rtasc, decl
    } = sunPos(jday);

  • The units of ndot and nddot fields on the SatRec object have changed:

    Fieldv6v7
    ndotrev/day²rad/min²
    nddotrev/day³rad/min³

    If you read these fields directly, you will need to adjust for the new units.

    Adjusting for new ndot and nddot
      import { constants } from 'satellite.js';

      const ndotRevPerDay2 = satrec.ndot * (constants.xpdotp * 1440);
      const nddotRevPerDay3 = satrec.nddot * (constants.xpdotp * 1440 * 1440);

Features​

  • Function shadowFraction(sunEciAU, satelliteEciKm) - calculates the fraction of the Sun's disc that is obscured by the Earth as seen from a satellite (0 = fully lit, 1 = umbra, anything in between = penumbra). See Sun & Shadow.
  • Bulk Propagation API - a C++ compiled to WASM alternative to pure JS functions, designed for propagating large numbers of satellites and dates. See Bulk Propagation API.

v5 to v6​

Breaking changes​

  • The return type of the sgp4 and propagate functions is changed from:

    {
      position: EciVec3<Kilometer> | false
      velocity: EciVec3<KilometerPerSecond> | false
    }

    to:

    null | {
      position: EciVec3<Kilometer>
      velocity: EciVec3<KilometerPerSecond>
      meanElements: MeanElements
    }

    Where, if propagation failed, null is returned instead of individual keys set to false. This should simplify your TypeScript code a bit.

  • There were overloads of gstime and return types of sgp4 and propagate that were not documented by TypeScript definitions as of v5, but could happen in runtime. If your code doesn't rely on those, or if you use TypeScript and your code compiles with v5, this doesn't impact you.

v4 to v5​

This release aligns the Satellite.js output to official USSF output by fixing errors in calculations and using WGS72 instead of WGS84. There are no other changes.