gmat-czml viewer
Optional Cesium ion token (else offline imagery):
…or drag a .czml file anywhere onto the page.

Open this over a local web server

This page is loaded from a file:// URL. Browsers treat that as a unique origin and block the cross-origin Web Workers CesiumJS needs, so the 3D globe can't load.

From the repository, run

python examples/serve.py

and it will serve this folder and open the viewer for you.