# Sky Launch — Full Site Content > Real-time SpaceX launch visibility tracker for every US launch site. > Website: https://www.skylaunch.app > About: https://www.skylaunch.app/about.html > Calendar Feed: https://www.skylaunch.app/calendar.ics > Created By: Joey Bolohan (https://www.linkedin.com/in/joey-bolohan/) --- ## What Sky Launch Is Sky Launch answers one question: **"Can I see the next rocket launch from where I am?"** It tracks every upcoming and recently-completed SpaceX launch across all four active US launch sites and calculates a personalized visibility score (0–10) based on the viewer's exact location, the sun's angle at launch time, cloud cover, and atmospheric visibility. It's free, requires no account, and stores the user's location only in their browser's localStorage. Sky Launch is a mobile-first progressive web app (PWA) that can be installed on iOS and Android home screens. It works offline for previously-loaded data. --- ## The Visibility Score Explained (0–10) Every launch receives a score from 0 to 10. The score is the product of four independent factors: ### 1. Distance from the Launch Pad Distance is calculated using the Haversine formula between the user's coordinates and the launch pad coordinates supplied by The Space Devs Launch Library 2 API. **Base score by distance:** - **0–20 miles**: 10 (perfect — front-row seat) - **20–100 miles**: 8–9 (excellent) - **100–200 miles**: 6–8 (good if conditions are right) - **200–300 miles**: 4–6 (only visible during twilight) - **300–400 miles**: 2–4 (twilight only, clear skies only) - **400+ miles**: 0–2 (effectively not visible) **Twilight bonus:** During twilight launches, the distance cutoffs effectively double because the plume is lit by the sun at high altitude. A twilight launch within 200 miles can score a 10 even though the same launch at noon would score a 6. ### 2. Sun Angle and Lighting Phase This is the single biggest factor at distance. Sky Launch uses the SunCalc library to compute the sun's altitude in degrees relative to the horizon at the exact time and location of the launch. **Lighting classifications:** - **Day** (sun above 0°): Rocket visible only up close. Exhaust trail washed out by daylight. - **Civil Twilight** (sun 0° to –6°): Golden-hour lighting. Good contrast. - **Nautical Twilight** (sun –6° to –12°): **OPTIMAL.** Peak jellyfish-plume viewing. Sky is dark at ground level but the upper atmosphere is still sunlit. - **Astronomical Twilight** (sun –12° to –18°): Very dark sky. Rocket exhaust still catches high-altitude sunlight during initial ascent. - **Night** (sun below –18°): Fully dark. Only visible if close enough to see engine glow directly. ### 3. Cloud Cover Cloud cover is pulled from the Open-Meteo weather API for the user's exact coordinates at the launch time. It's reported as a percentage (0–100%). **Penalty scale:** - **0–30%**: No penalty - **30–60%**: –1 to –2 points - **60–90%**: –3 to –4 points - **90%+**: –5 points (effectively not visible) ### 4. Atmospheric Visibility Visibility (in miles) is also pulled from Open-Meteo. It accounts for haze, fog, smoke, and general air quality. **Penalty scale:** - **10+ miles**: No penalty - **5–10 miles**: –1 point - **2–5 miles**: –2 points - **Under 2 miles**: –3 points ### Score-to-Rating Labels - **9–10**: Excellent (shown in bright green, highlighted) - **7–8**: Good (green) - **5–6**: Fair (yellow) - **1–4**: Poor (red) - **0**: Not Visible - **NA / Pending**: Weather forecast not yet available (launches more than 16 days out) --- ## Supported Launch Sites Sky Launch tracks all four active US SpaceX launch sites: ### Vandenberg Space Force Base - Location: Lompoc, California - Pads: SLC-4E, SLC-4W - Missions: Sun-synchronous, polar, and high-inclination orbits (Starlink, NASA, DOD, commercial) - Best viewing corridor: Santa Barbara County, Los Angeles basin, Bay Area during southward launches ### Cape Canaveral Space Force Station - Location: Cape Canaveral, Florida - Pads: SLC-40 - Missions: ISS cargo, commercial Starlink, GTO commsats - Best viewing corridor: Orlando, Daytona Beach, Jacksonville, up the East Coast during northerly launches ### Kennedy Space Center - Location: Merritt Island, Florida - Pads: LC-39A - Missions: Crew Dragon, Falcon Heavy, Starlink - Best viewing corridor: Same as Cape Canaveral — Kennedy pads are adjacent ### Starbase - Location: Boca Chica, Texas - Pads: Orbital Launch Pad (OLP) - Missions: Starship development flights - Best viewing corridor: South Padre Island, Brownsville, along the Gulf of Mexico coast Users can filter by site in the header, or view all launches together. --- ## Launch Card Details Every launch card displays: - Mission name (e.g. "Starlink 9-8") - Rocket type (Falcon 9, Falcon Heavy, Starship) - Launch site and pad name - Live countdown timer (updates every second) - Visibility arc gauge with the user's personal score - Launch status: Go, TBD (to-be-determined date), TBC (to-be-confirmed), Success, Failure, In Flight - Distance from the user in miles - Sun altitude in degrees and lighting classification - Cloud cover percentage - Atmospheric visibility in miles - Launch probability (when published by the launch provider) - Mission description (satellite purpose, payload details) - Video links: YouTube webcasts, SpaceX official stream, NASA TV, launch provider streams - Embedded YouTube player when a live stream URL is available The single next upcoming launch gets a **hero card** with a larger display, animated countdown, and prominent score visualization. --- ## Tools Available on Every Launch Card ### Share Button Uses the Web Share API to open the device's native share sheet (iMessage, WhatsApp, email, etc.) with pre-formatted text: - Mission name and rocket - Launch time in the user's local timezone - Visibility score for their location - Direct link to the launch on Sky Launch Falls back to clipboard copy on desktop browsers that don't support Web Share API. ### Add to Calendar Downloads a single-event ICS file with: - Launch time with 30-minute event duration - Location set to the launch site - Full mission description - Watch link (first available video URL) - Two alarms: 60 minutes before and 15 minutes before launch Works with Apple Calendar, Google Calendar, Outlook, Fantastical, and any ICS-compatible calendar. ### Visibility Breakdown (tap the score gauge) Opens a modal showing exactly how each of the four factors contributed to the score: - Distance contribution (+ points based on miles) - Sun/lighting contribution (+ points based on phase) - Cloud cover penalty (– points) - Atmospheric visibility penalty (– points) - Any capped-at-zero logic explained This transparency helps users understand whether it's worth stepping outside. --- ## Calendar Feed (Subscribe) Sky Launch publishes a live ICS calendar feed that auto-refreshes in your calendar app. **Full feed (all sites, all launches):** `https://www.skylaunch.app/calendar.ics` **Site-filtered feeds:** - `https://www.skylaunch.app/calendar.ics?site=vandenberg` - `https://www.skylaunch.app/calendar.ics?site=canaveral` - `https://www.skylaunch.app/calendar.ics?site=kennedy` - `https://www.skylaunch.app/calendar.ics?site=starbase` **Single-launch feeds:** `https://www.skylaunch.app/calendar.ics?id={launch_id}` The feed refreshes every 12 hours for the full feed, every 2 hours for single-launch feeds. Past launches return HTTP 410 Gone after 24 hours so calendar clients clean them up. Each event includes two alarms by default: 60 minutes before launch and 15 minutes before launch. --- ## First-Time Setup On the first visit, Sky Launch asks for the user's location. There are two options: ### GPS (Recommended) Uses the browser's Geolocation API. Requires permission. Accurate to within a few hundred feet, which is important for distance-sensitive visibility scoring. ### Manual Entry User types a city, state, or ZIP code. Sky Launch geocodes the entry using Open-Meteo's free geocoding API. **The user's location is stored only in their browser's localStorage** under these keys: - `user_lat` — latitude (float) - `user_lon` — longitude (float) - `user_label` — human-readable label ("Palm Desert, CA") Location can be changed anytime from the header menu. Clearing localStorage triggers the setup overlay on next visit. --- ## Past Launches Section Launches that completed within the past 48 hours appear in a separate "Recently Launched" section at the bottom of the page. Each card shows: - Final launch status (Success, Failure, Partial Failure, In Flight) - Actual launch time - The visibility score the user would have seen This is useful for confirming whether a launch you saw in the sky was the one you expected, or reviewing a launch you missed. Launches older than 48 hours are removed from the UI but remain accessible via their calendar event until the 24-hour ICS cleanup window. --- ## Data Refresh Behavior - **Launch data** (Launch Library 2 API): Auto-refreshes every 5 minutes. Rate-limited to stay under the LL2 free tier (15 req/hr per IP). - **Weather data** (Open-Meteo): Fetched on every launch data refresh. - **Manual refresh**: Always available via the refresh button in the header. - **localStorage cache**: 5-minute TTL for LL2 response. Survives page reload. --- ## How Sky Launch Started Sky Launch was created by **Joey Bolohan** as a passion project for his two sons, Austin and Hunter. The first time the family saw a SpaceX launch was from Palm Desert, California, during a twilight window. The exhaust plume caught the sun and lit up the entire western horizon — a spectacular "space jellyfish" visible for hundreds of miles. For Hunter, it became a core childhood memory. He decided he wanted to be an astronaut and learn everything about rockets. Trying to time the next viewing, Joey discovered there was no good tool for answering the question: "Will I actually be able to see this launch from my house?" You need: 1. The launch to happen during a narrow twilight window 2. Clear skies over your location 3. A reasonable distance from the pad 4. Good atmospheric visibility No single site or app combined all four factors into a personalized score. So Joey built Sky Launch. Sky Launch remains free. No ads. No accounts. No tracking. The user's location never leaves their device. It runs on a single Node.js server with static HTML, CSS, and vanilla JavaScript — no frameworks, no build step. --- ## Frequently Asked Questions **Q: Can I see a SpaceX launch from my location?** A: Sky Launch calculates a personalized visibility score (0–10) for every upcoming SpaceX launch based on your exact location. It factors in distance to the launch pad, sun angle at launch time, cloud cover forecasts, and atmospheric visibility. Twilight launches (just after sunset or before sunrise) are the most spectacular because the exhaust plume catches sunlight while your sky is dark. **Q: How far away can you see a SpaceX launch?** A: Under ideal conditions (clear skies during twilight), SpaceX launches can be visible from over 300 miles away. The glowing exhaust plume is lit by the sun at high altitude while your sky is dark, creating the iconic "space jellyfish" effect that stretches across a large portion of the sky. **Q: What is the best time to see a rocket launch?** A: During twilight — roughly 30 to 90 minutes after sunset or before sunrise. The sky is dark at ground level but the rocket and exhaust plume are still lit by sunlight at high altitude. Sky Launch automatically detects these optimal windows and factors them into your visibility score. **Q: Why do twilight launches look so dramatic?** A: During twilight, the sun is below your horizon but still above the horizon at the altitude where the rocket is flying (roughly 100,000+ feet). The rocket and its exhaust plume catch direct sunlight against your dark sky, creating a glowing trail visible hundreds of miles away. The ice-crystal plume from the second-stage engine can expand into a massive "jellyfish" shape as it enters thinner atmosphere. **Q: Is Sky Launch free?** A: Yes, completely free. No ads, no accounts, no tracking. Built as a passion project by Joey Bolohan for his family. **Q: Which launch sites are tracked?** A: All four active US SpaceX sites: Vandenberg Space Force Base (California), Cape Canaveral Space Force Station (Florida), Kennedy Space Center (Florida), and Starbase (Texas). **Q: Does Sky Launch track non-SpaceX launches?** A: Currently no — the tool focuses on SpaceX (Falcon 9, Falcon Heavy, Starship) because that's the most active cadence and what the creator's family watches. The underlying data source (Launch Library 2) supports other providers, so expanding is possible. **Q: How accurate is the score?** A: The score is deterministic based on distance, sun angle, cloud cover, and visibility. Distance and sun angle are exact. Cloud cover and visibility are forecasts from Open-Meteo and can drift as the launch approaches — the score refreshes every 5 minutes to stay current. Within 24 hours of launch, weather forecasts are highly reliable. **Q: Can I subscribe to launch notifications?** A: Yes. Subscribe to the calendar feed at `https://www.skylaunch.app/calendar.ics`. New launches appear automatically with 60-minute and 15-minute reminders. Filter by site or get all launches. **Q: Where is my location stored?** A: Only in your browser's localStorage. It never leaves your device. Sky Launch has no user database, no accounts, and no analytics that track individuals (only aggregate Google Analytics page views). **Q: Can I install Sky Launch on my phone?** A: Yes. Sky Launch is a Progressive Web App. On iOS, tap Share → Add to Home Screen. On Android, tap the install prompt or the browser menu → Install app. Once installed, it opens in standalone mode with a custom splash screen and works offline for previously-loaded data. **Q: Who built this?** A: Joey Bolohan — a software engineer in Southern California. Full bio at https://www.linkedin.com/in/joey-bolohan/. Built for his sons Austin and Hunter. --- ## Technical Overview - **Frontend**: Vanilla JavaScript, HTML5, CSS3. No framework. No build step. - **Backend**: Node.js HTTP server (server.js). Serves static files + `/calendar.ics` dynamic endpoint. - **Data sources**: - Launch Library 2 (ll.thespacedevs.com, v2.2.0) — launch data - Open-Meteo (api.open-meteo.com) — weather + geocoding - SunCalc library — sun altitude calculations (client-side) - **Hosting**: Railway - **Analytics**: Google Analytics (aggregate only — no per-user tracking) --- ## Contact Website: https://www.skylaunch.app About: https://www.skylaunch.app/about.html Creator: Joey Bolohan — https://www.linkedin.com/in/joey-bolohan/