ISS Real-Time Tracker User Guide

User Guide

Pass Predictions

Tapping the telescope icon at the bottom of the main screen starts the process of computing up-coming visible ISS passes. First, ISS Real-Time Tracker gets your current location's coordinates. Then, it computes the visible passes for that location. The default number of days to predict passes is set in Settings. The passes are listed in chronological order along with detailed viewing data.

Data for each pass includes:

  • Date of the pass
  • Rating (0, 1, 2, or 3 stars)
  • Visible duration (in minutes and seconds)
  • Max visual magnitude (using same scale as astronomical brightness, i.e., apparent magnitude)
  • Time, azimuth, elevation, and compass direction for the start time, max elevation time, and end time

Each pass is rated based on its maximum magnitude (i.e., brightness). With the brightest passes gettiing the highest reatings. Passes are rated with 0, 1, 2, or 3 stars corresponding to fair, good, better, best. Passes rated at least fair, are highlighted with a green background in the date field.

Adding a Pass Event to Your Calendar

Tap any pass in the table to add it as an event in your calendar. When adding a pass to your calendar, two alerts will be set: the first for 1 hour before and the second for 20 minutes before the start of the pass. The starting and ending times for the pass are saved in the event in your calendar, along with the maximum magnitude, as well as the starting, maximum, and ending azimuths and elevations for the pass.

Change Number of Days to Compute & Refresh

Tap the Calendar icon at the top-right of the screen to change the number of days to compute and refresh the list. To change the number of days so that the app remembers your setting for next time, change it in Settings.

Tap ⟵ to return to the map and resume tracking.

  • The pass predictions become less certain the further out in time they go.
  • Overhead passes returned are only those visible from your location for at least 300 seconds (5 minutes) and where the ISS is illuminated by the Sun.
  • If there are buildings, trees, or other obstructions, and depending upon the weather and other viewing conditions, you may not be able to spot the station.
  • You must give ISS Real-Time Tracker access to your location. When asked, tap "OK." You can change this permission in your device's Settings app.
  • Calendar events are saved in your default calendar.

Tracking the ISS

To locate and track the International Space Station in real time, tap the play button at the bottom of the screen. To pause tracking, tap the pause button.

You can select from the following map types in Settings:

  • Standard (shows names, roads, and borders)
  • Satellite (shows terrain only)
  • Hybrid (the default setting: shows borders, names, roads, and terrain)

To zoom in or out of the map, use the slider control at the top of the map. This changes the scale of the map, which is displayed in degrees to the right of the zoom slider.

You can set the map scale range in Settings to any of the following ranges (in degrees):

  • Fine: 0.10° - 3.00° (0.15° - 3.00° for iPad)
  • Small: 0.33° - 10.00°
  • Medium: 1.00° - 30.00° (the default setting)
  • Large: 3.00° - 90.00°

There are three styles of markers, which you can select in Settings:

  • ISS icon (the default setting)
  • Circular
  • Small +

The time interval between map updates is automatically set from 1 to 6 seconds, based upon the zoom slider setting. With the slider all the way to the left, the update interval is set at 1 second. As you drag the slider right, it increases by 1 second up to a maximum interval of 6 seconds. This keeps the relative motion of the map roughly equal at all scales within a given range.

Copy Info to the Clipboard

Tap the copy button next to the info box on bottom of the map to copy the ISS's location, altitude, velocity, and associated time to the clipboard. You can then paste the data in another app.

  • If the Information box overlay setting is turned off in Settings, copy will not be available.
  • The music soundtrack will be disabled (not play) by default. Click the ♪ icon at the upper-right to toggle the soundtrack on/off.

Landsat 8 Imagery

Tap the satellite button on bottom of the map to display a NASA Landsat 8 image at the current map coordinates. Image covers an area determined by the Img Scale selector in Settings. The coordinates, date, and time the Landsat 8 image was captured is displayed above the image, along with the scale in degrees and percentage of cloud cover. Tracking will be paused while the Landsat 8 image is being downloaded. This allows you to view the Landsat image and then return to the map and compare the two views.

Tap ⟵ to return to the map. Tap the Play button to resume tracking.

Change Image Scale

To change the image scale, tap the scale button on the upper-right. To change the image scale so that the app remembers your setting for next time, change it in Settings.

Save Landsat 8 Image in Photos

Tap the image to save it to your photo library.

  • If the ISS is over open ocean, or if Landsat 8 imagery is not available for the current map coordinates, no image will be displayed.
  • To display images with high cloud cover (›80%), turn this on in Settings. Otherwise, if ISS Real-Time Tracker determines that the image has more than 80% cloud cover, it will not be displayed.
  • You must give ISS Real-Time Tracker access to your photos to save an image. When asked to grant this permission, tap "OK." You can change this permission in your Settings app.

High Definition Earth Viewing (HDEV) Experiment

Tap the TV button on bottom of the map to get the live video stream from the High Definition Earth Viewing (HDEV) experiment on the ISS. Note that NASA and the High Definition Earth Viewing Experiment control this, so the app receives the video stream as it is. If the screen is black, then the ISS is either in nighttime or switching cameras.

Tap ⟵ to return to the map.

  • While the experiment is operational, views will sometimes sequence through the experiment's four different cameras.
  • During camera switches, a gray or blue color slate may appear.
  • Black Image = ISS is on the night side of the Earth.
  • Image of sunset with words displayed = Switching between cameras, or communications with the ISS is not available.
  • If the video is black, or nearly black, don't worry — the space station is likely just on Earth's night side. (The station completes one orbit every 90 minutes, so you won't have to wait too long for our gorgeous planet to roll into view once again.)

Current Crew

Tap the space suit button at the bottom of the screen to get a table of information about the current ISS crew.

Get Crew Member Bios

Tap ⓘ in any cell in the table to pop up a short bio. Tapping anywhere else in a cell brings up the crew member's full bio. Tap ⟵ to return to the table.

Copy Crew Data to the Clipboard

Tap the copy icon at the top-right of the screen to copy the crew names, titles, and nationalities to the clipboard. You can then paste them in another app.

Tap ⟵ icon to return to the map and resume tracking.


All of your current user settings are automatically saved on your device when you exit the app or switch to another app. This also includes the current zoom slider position. Each time you run ISS Real-Time Tracker, your settings are restored.

Tapping the Reset button at the upper-right of Settings, will clear all your user settings and change them back to their defaults. The zoom slider will reset to its default (center) position and What's New and other messages will be restored.

Tap Done to return to the map view and resume tracking.

© 2018-2019 Michael Stebel Consulting, LLC
All rights reserved

ISS Real-Time Tracker is a trademark
Michael Stebel Consulting, LLC

© 2016-2019 Michael Stebel Consulting, LLC. All Rights Reserved.

Powered by TruVisibility TruVisibility