List of satellite pass predictors

Ground track example from Heavens-Above. An observer in Sicily can see the International Space Station when it enters the circle at 9.26 p.m. The observer would see a bright object appear in the northwest, which would move across the sky to a point almost overhead, where it disappears from view, in the space of three minutes.

The following is a list of tools on a variety of platforms that may be used to predict the pass of an orbiting artificial satellite over a given point on Earth. They are used to generate a list of dates, times and directions when and where objects such as the International Space Station, Genesis, or Tiangong 1 space stations will be visible to ground observers, as well as many man-made objects that can be seen with the unaided eye including the Hubble Space Telescope.

Web based

• Heavens-Above, called "the most popular website for tracking satellites" by Sky and Telescope magazine and referenced by NASA websites. Linked from both NASA and ESA websites as a reference for locating satellites and spacecraft. Includes predictions for the ISS, space shuttle and other bright satellites, planets, minor planets, and comets.
• JPass, a java based web application. Offline since April 2010, replaced by NASA Skywatch web application.
• NASA Skywatch, Java based web application. Predicts visible passes for spacecraft, satellites and space debris.
• AMSAT Online Satellite Pass Predictions,
• n2yo provides real time tracking and pass predictions with orbital paths and footprints overlaid on Google Maps.
• CalSky a service offered by Arnold Barmettler for astronomers to plan their observing sessions. Features a calendar (and/or email notifications) generated for your location including information on aurora, comets, tides, solar and lunar eclipses, planets, bright satellite passes (ISS, HST, etc.), occultations, transits, Iridium flares, and decaying satellites that may be visible.
• SightSpaceStation Shows a simulated view from the ISS via Google Earth by default. Shows predictions for upcoming passes which can be simulated using Google Street View allowing users to see what a pass will look like in relation to familiar landmarks around them. Available natively in English, Japanese, and Spanish and with automated translation to other languages. Also available as an Android, iPhone and iPad app.
• ISS Tracker Real time tracking of the ISS's position displayed on Google Maps.
• IXION [1] plots satellite ground-track on Google Map (you can also get representation on a map with the choice of more than 150 projections). Representation of 3D-orbit is obtained with Google Earth. The sampling is presented with very detailed pictures. IXION also represents the satellite orbits around Mars, Venus and other planets, around the Moon, Europa, and other natural satellites.
• Where the ISS at? provides real time tracking and push notifications (via Twitter or email) for passes over your location.
• Digital Astrolabe provides a searchable map of current satellite positions using Google Maps, linked to a chart of satellites currently visible in the sky from your location.

Mobile OSes

iOS

This section includes applications for the iPhone, iPad and iPod touch. Apps generally use coordinates provided by the device's built in GPS. Some require an active internet connection others update periodically

• Sat Seeker - Displays predictions of upcoming passes for the user's location with indication of whether they will be visible or not. Includes an augmented reality view to demonstrate the path of the ISS over the user's current location. No active internet connection required to calculate pass predictions (requires periodic connection to fetch new orbital data).
• ISS Spotter - free iPhone app with current ISS location and path, forecasts, compass and alarm function.
• GoSatWatch from GoSoftWorks, supports multiple viewing sites (home, vacation spot, etc.), no internet connection required (one data is loaded and periodically updated). View satellite position on world map or a simple polar chart showing the path the satellite will take across your sky.
• SightSpaceStation iPhone/iPad version of SightSpaceSation. On iPhone and iPad2, uses the camera for augmented reality view of passing satellites to help viewers locate them in the sky.
• ISS Visibility, interface to Heavens-Above, predictions up to 30 days out, ground tracks, star chart with path shown.
• Iridium Flares - predicts Iridium Flares only
• Sputnik! - pass predictions for Iridium Flares and ISS.
• Satellite Flybys (formerly Global Flybys) - displays predictions for upcoming passes, provides a countdown time and alarms for user selected satellites done by coordination of Finch consulting with data access through Chris Peat, Heavens-Above GmbH. Also available for Android phones.

Android

• ISS Detector - Location based ISS and Iridium flare sighting prediction. This app includes a forecast for the weather condition. There are extensions available for detection of amateur radio satellites and for famous objects like the Hubble Space Telescope and the Kepler (spacecraft).
• Heavens Above: now renamed to SatTrack, see below.
• SightSpaceStation - See SightSpaceStation above
• Iridium Flares - predicts Iridium Flares only
• Satellite AR, by Analytical Graphics augmented reality view of the sky for currently visible satellites only. Includes modes for ISS and bright objects as well as modes which include the thousands of all known satellites.
• SatTrack, previously known as Heavens Above - This application reveals all iridium flares and satelittes (including international space station and amateur radio satellites) passing by at your location. An auto-adjusting compass pointing in the direction of the satellite or flare helps you tracing the object. Notifications can be enabled to warn you whenever a satellite of interest passes by.
• Spy Satellite, lists upcoming passes for visible satellites
• Satellite Flybys (formerly Global Flybys) - displays predictions for upcoming passes, provides a countdown time and alarms for user selected satellites. Also available for iOS.

Windows Phone

• ISS Tracker - pass predictions for ISS at your location, with satellite position on map, Live Tile notifications and forecast for the weather condition.

Windows CE

• PocketSat+
• pTrack

BlackBerry

• PocketSat+

Windows

• Footprint
• Nova
• WXTrack
• Orbitron
• SatBuster
• PreviSat

Linux

• gpredict [2]
• ktrack [3]
• Predict [4]
• XEphem [5]

Notifiers

• Twisst individual notification of upcoming ISS passes via Twitter.

Software libraries

• Astro::satpass Perl library by Tom Wyant, calculates star, sun, and moon positions as well as satellite pass predictions. Interfaces with Celestrak or Space Track.
• OreKit Java library for low level space dynamics library.

Raw orbital data

All websites and applications base their predictions on formula using two-line element sets which describe the satellites and their orbits.

• Celestrak provided by Dr. T.S. Kelso, includes visible objects, openly available
• SpaceTrack maintained by the United States Strategic Command provides orbital information on unclassified satellites requires an account but is available for educational and hobbyist use as well as military, government and spacecraft and payload owners.
• JPL Horizons On-Line Ephemeris System, maintained by the Solar System Dynamics Group at the Jet Propulsion Laboratory, provides ephemeris for asteroids, comets, planets, moons, solar system planets, the Sun, and some spacecraft.
• Satellite Calculations