How to See the Space Station with a Telescope

international space station

International Space Station

The International Space Station can actually be seen with the naked eye. Nominally, its visual magnitude from the ground can make it appear as bright as the planets Jupiter and Venus. It will appear as a bright star traveling in a straight line. Unlike a plane, the light will not blink. It can take about 4 minutes for the International Space Station to cross the entire sky. The station does about 15 orbits of the Earth in a 24 hour period meaning that it will pass over head about every hour and a half.

Viewing the International Space Station

A reflector telescope works well for observing the International Space Station, particularly if your observing from light polluted areas, a problem which many of us have to cope with. The Space Station a tricky target to acquire since it moves very fast.

First, you need to know when to look for the Station, and where. That depends on where you are located. To make things easy, use the NASA Human Space Flight Realtime Data tool. Just put in your location and click “Next Sighting” to find out the specific time to look for the ISS. Next, click “Sky Track” to reveal the trajectory of that pass in a sky map.

Projecting the station’s trajectory is easy once you spot it with the naked eye. Point your telescope to a spot where the ISS will end up passing through. Assuming the positioning was done correctly then it’s just a matter of waiting a few seconds before seeing the ISS in the field of view. You can then move the telescope and keep following the target along its trajectory. It’s not as easy as it sounds! Alternatively, you can predict the trajectory and slowly move your telescope along that path until the ISS catches up. Again, this can be difficult to do. Start with low magnification until you get the hang of it.

Acquiring and maintaining the ISS target becomes a lot more challenging at higher magnifications. As more magnification is used, less “space” can be viewed at one time. Taking a picture of the ISS through a telescope is also a popular challenge and a rewarding accomplishment. 40X magnification is sufficient to snap a great picture of the ISS. Our telescope magnification calculator can help determine what eyepiece is appropriate to use with your specific telescope.

Interesting Facts about the Space Station

  • The ISS solar array surface area could cover the U.S. Senate Chamber three times over.
  • ISS eventually will be larger than a five-bedroom house.
  • ISS will have an internal pressurized volume of 33,023 cubic feet, or equal that of a Boeing 747.
  • The solar array wingspan (240 ft) is longer than that of a Boeing 777 200/300 model, which is 212 ft.
  • Fifty-two computers will control the systems on the ISS.
  • More than 100 space flights will have been conducted on five different types of launch vehicles over the course of the station’s construction.
  • More than 100 telephone-booth sized rack facilities can be in the ISS for operating the spacecraft systems and research experiments.
  • The ISS is almost four times as large as the Russian space station Mir, and about five times as large as the U.S. Skylab.
  • The ISS will weigh almost one million pounds (925,627 lbs). That’s the equivalent of more than 320 automobiles.
  • The ISS measures 357 feet end-to-end. That’s nearly equivalent to the length of a football field including the end zones.
  • 3.3 million lines of software code on the ground supports 1.8 million lines of flight software code.
  • 8 miles of wire connects the electrical power system.
  • In the International Space Station’s U.S. segment alone, 1.5 million lines of flight software code will run on 44 computers communicating via 100 data networks transferring 400,000 signals (e.g. pressure or temperature measurements, valve positions, etc.).
  • The ISS will manage 20 times as many signals as the Space Shuttle.
  • The entire 55-foot robot arm assembly is capable of lifting 220,000 pounds, which is the weight of a Space Shuttle orbiter.
  • The 75 to 90 kilowatts of power for the ISS is supplied by an acre of solar panels.