Spotting the International Space Station

Astronaut Chris Cassidy works outside the space station on May 11, 2013.  Credit: NASA
Astronaut Chris Cassidy works outside the space station on May 11, 2013. Credit: NASA
Almost everyone has heard of the International Space Station (ISS). It is one of the most spectacular technological achievements ever, but it is easy to take it for granted. After all, it has been in orbit for more than 13 years. Astronauts have lived on board all that time, conducting science experiments and learning the kinds of things that will help humans extend their reach into space. Since ISS may be the coolest laboratory ever built, we recommend making a New Year’s commitment to keeping track of what’s going on there.

Luckily, NASA makes it easy to keep up with ISS. On the web site http://spacestationlive.nasa.gov/ you will find animations and education resources about “humankind’s permanent outpost in space.” You can find details of the daily activities for each astronaut, along with timelines and live video feeds. You can view the same data being viewed by ground control officers at NASA, so if you’ve ever wanted to try your hand at being a flight director, start here.

For an overview of what is going on with ISS, NASA provides a great option. The YouTube channel ReelNASA provides a weekly newscast about what’s happening aboard the International Space Station. You’ll find links to in-depth information about the experiments and projects that are discussed. You can even send in your own questions. It is pretty cool.

The space station, including its large solar arrays, spans the area of a U.S. football field, including the end zones, and weighs 924,739 pounds. The complex now has more livable room than a conventional six-bedroom house, and has two bathrooms, a gymnasium and a 360-degree bay window.
The space station, including its large solar arrays, spans the area of a U.S. football field, including the end zones, and weighs 924,739 pounds. The complex now has more livable room than a conventional six-bedroom house, and has two bathrooms, a gymnasium and a 360-degree bay window.
Spotting the International Space Station
For the ultimate in “keeping up with the ISS,” nothing beats taking a look with your own eyes. The ISS is the size of a football field and orbits Earth at an average altitude of 220 miles. Just before sunrise or when night has fallen where you live, the ISS is sometimes overhead and high enough to still be in the sunlight. It is highly reflective and very bright, so it is easy to spot if you know when to look. It moves quickly across the sky, which isn’t a surprise considering that the ISS orbits the Earth every 90 minutes and travels at a speed of 17,500 miles per hour. Between moving fast and being wildly bright, it is easy to spot.

To know when to look, go the the NASA site http://spotthestation.nasa.gov/ and click on Location Lookup. Simply enter your location information (Country, State, City, etc.). The site will display information about when the ISS will be visible to you. The main thing, of course, is to find a day and time when you can go outside and look, and then to hope it is not too cloudy during your viewing window.

The results for your local area provide all the information you need to pick a good viewing time. Then you just have to hope it is not cloudy.
The results for your local area provide all the information you need to pick a good viewing time. Then you just have to hope it is not cloudy.
The next important thing is to make sure the ISS will be high enough for you to see. For the “Max Height” column, know that 90 degrees equals directly overhead, so any number above, say, 45 degrees will put the ISS high in the sky. Lower numbers mean the ISS will appear closer to the horizon, so trees or buildings might be in the way and block your line of sight.

Use this graphic to visualize what path the ISS might take in the sky. Credit: NASA.
Use this graphic to visualize what path the ISS might take in the sky. Credit: NASA.
And remember, sight lines work both ways. Since NASA streams live views of the Earth from the ISS, you can very easily go outside to wait for the ISS to appear overhead while watching the live view of Earth from the ISS on a smartphone or tablet computer (if you have a web connection). This allows you to see what astronauts aboard the ISS see if they look down. If it is just past sunset where you live, for instance, look for the line on Earth between night and day to figure out about where you are in terms of east and west.

When the ISS blazes its way across the sky hundreds of miles overhead, you will have achieved a dual, realtime perspective that would have been almost impossible to dream of just a few decades ago. Give it a try!

This picture shows a five-second exposure of the ISS passing just above the Pleiades star cluster on Dec. 27, 2013. The length of the path over five seconds gives you an idea of how fast the ISS moves across the sky.
This picture shows a five-second exposure of the ISS passing just above the Pleiades star cluster on Dec. 27, 2013. The length of the path over five seconds gives you an idea of how fast the ISS moves across the sky. Credit: Clifton Dowell