ICS Space Events Calendar

The New York Times used to publish a space calendar (rocket launches, eclipses, meteor showers, and other astronomical events) as a subscribable ICS feed, but it was discontinued.

Nothing else fills the void. Existing options either cover only one category (launches but no sky events, or sky events but no launches), require multiple separate calendar subscriptions, or don't let you filter out the events.

This project fixes that, one automatically updating calendar feed with your choice of categories.

You pick which categories you want. Everything appears in a single calendar subscription.

Sky events: moon phases, meteor shower peak nights, solar and lunar eclipses, solstices and equinoxes

Planetary events: oppositions (best viewing nights for Mars, Jupiter, Saturn), Mercury and Venus elongations, notable asteroid close approaches, comets

Rocket launches: crewed missions, maiden flights, heavy-lift vehicles (Falcon Heavy, Starship, SLS, New Glenn), and flagship science payloads. No Starlink batches.

Space history milestones: 20, 25, 50, 75, and 100-year anniversaries of landmark moments in spaceflight and astronomy

Aurora borealis: location-aware forecasts based on NOAA's 3-day Kp index. Enter your zip code and only get notified when a storm is likely visible at your latitude. Note: for same-day alerts, use a real-time app, since calendar sync isn't fast enough.

Visit the configurator, select your categories, then add it straight to Apple Calendar or Google Calendar. Or copy the URL into any app that takes an ICS feed.

The same data is also available as JSON if you want to use it outside of a calendar app:

GET https://space-calendar.lukekorth.com/feed.json?c=moon-phases,meteor-showers

Returns { "name": "...", "events": [...] } where each event is a CalendarEvent object. Accepts the same query parameters as the ICS feed:

Responses set Cache-Control: max-age=3600 and an ETag. If you poll the feed, send the ETag back as If-None-Match and you'll get a 304 Not Modified instead of the whole calendar.

Prefer a real IANA zone name for tz. A fixed offset (UTC+2, +02:00) is accepted, but it carries no daylight-saving rules, so times in event descriptions will be an hour off for part of the year if your region observes DST.

Static astronomical data (eclipses, moon phases, meteor showers, planetary events, history milestones) is generated once a year from USNO and JPL data via GitHub Actions and stored in this repo. Rocket launch data is fetched live from The Space Devs Launch Library 2 and cached hourly. Aurora forecasts are fetched from NOAA SWPC and cached every few hours. A Cloudflare Worker merges the requested categories into a single ICS or JSON response at request time.

CATEGORIES.md — every included and excluded event category, with reasoning

EVENT_FORMAT.md — how each event type is structured: timing, title format, body content, and source links

ARCHITECTURE.md — system design, data flow, and tech stack

Contributing

Contributions welcome. The most valuable ongoing contribution is maintaining the curated data files:

For bugs, data corrections, or feature requests, open a pull request or issue.

Space Calendar is free, has no ads, and requires no account. If it's useful to you, sponsoring on GitHub helps cover what it costs to run.