[benweru]

Summary

• Fetches CelesTrak GP TLEs (FORMAT=TLE), caches them with fetchedAt, and propagates ECI position with SGP4 (satellite.js).
• Catalog: ISS 25544, Landsat 9 49260, CUTE-1 (CO-55) 27844.
• Brief: docs/tasks/sprint13-web-tle-sgp4.md

A TLE is a snapshot of an orbit. SGP4 turns it into a position. Good for days, not months.

Test plan

• make test
• cd web && npm test (fixture only, no network)

.venv/Scripts/python -m pytest -q -m "not cfs and not docker and not linux_i2c"
72 passed, 4 skipped, 15 deselected in 5.27s

Test Files  5 passed (5)
     Tests  7 passed (7)

Web tests (7) cover parse, cache round-trip, mocked fetch, and ISS in LEO near the fixture epoch.

Live CelesTrak ISS pull used to seed the fixture (2026-10-19):

ISS (ZARYA)
1 25544U 98067A   26292.43498098  .00007189  00000-0  13878-3 0  9990
2 25544  51.6326  45.2419 0006754 282.9887  77.0347 15.48939196591015

What's still missing

• Nairobi look angles / next pass (sprint 14).
• Cesium globe (sprint 15). Production CORS: dev uses a Vite proxy; a static host may still need a proxy.