Hands-on Activity: Satellite Tracker

Contributed by: Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

A picture of a satellite in space.
Students examine the space station using satellite tracking
Copyright © http://spaceflight.nasa.gov/gallery/images/station/assembly/html/s100e5958.html


Students use satellite tracking software available on the Internet to monitor a very large satellite, the International Space Station. Using information from this online resource, students predict and graph the motion of the space station at their location and create a 3-D display of its path through the sky.
This engineering curriculum meets Next Generation Science Standards (NGSS).

Engineering Connection

Engineers continue to seek safe and efficient ways of space travel. Software engineers work with aerospace engineers to create tools, such as the online tracking programs Skywatch and STSPlus, to advance their ability to make accurate plans. Engineers take advantage of the power of computers to create models and programs that help them analyze or create a design, or make long-range predictions using changing variables.

Learning Objectives

After this activity, students should be able to:

  • Define key navigational terms like azimuth, elevation, and range.
  • Create a scaled 3-D model of a satellite's trajectory
  • Understand geometry of circles and ellipses

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Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

  • Analyze and interpret data to determine scale properties of objects in the solar system. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment?
  • Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic geometric software, etc.). Copying a segment; copying an angle; bisecting a segment; bisecting an angle; constructing perpendicular lines, including the perpendicular bisector of a line segment; and constructing a line parallel to a given line through a point not on the line. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Information and communication systems allow information to be transferred from human to human, human to machine, and machine to human. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment?
  • Describe the nature of the attribute under investigation, including how it was measured and its units of measurement. (Grade 6) Details... View more aligned curriculum... Do you agree with this alignment?
  • Direct and indirect measurement can be used to describe and make comparisons. (Grade 8) Details... View more aligned curriculum... Do you agree with this alignment?
Suggest an alignment not listed above

Materials List

Each group should have:

  • String
  • 2 foam balls (3-inches [7.6 cm] in diameter)
  • Cellophane tape
  • Masking tape
  • Yard stick and or tape measure (groups can share)
  • Protractor (the bigger the better; groups can share)
  • Scissors

For the entire class to share:

  • Computer(s) with internet access to the Skywatch website


The International Space Station (ISS) is a very large satellite that orbits the Earth. It is 3,300 sq. ft. in area, and moves in an almost circular low-Earth orbit, about 250km above the surface of the Earth. In this activity, you will learn how to predict and track the ISS' path using special computer software and how the paths of spacecraft and satellites can be calculated and accurately predicted. Using Skywatch 1 and STSPlus 2, online tracking software, the unimaginable can be done! To create these programs, you need a college degree in Aerospace Engineering, but, fortunately for us, middle school students just need access to a computer to use these programs.



Three key terms used in this activity are:

Azimuth – the number of degrees measured clockwise from the northern horizon. An object at 90 degree azimuth is due east. An object at 270 degree azimuth is due west.

Elevation – the height of an object, measured in degrees above the horizon. An object directly overhead is at a 90 degree elevation. An object on the horizon is at 0 degrees elevation.

Range – the distance from where you are located to a spacecraft or satellite.

Before the Activity

  • Gather the materials and equipment needed.
  • Run the Skywatch3 program and pick a day within the next week or so for the students to find and track the ISS. Become familiar with the software before showing it to your students. See Troubleshooting Tips for more details.
  • Mark a point in the center of the room that will represent your city. Using masking tape, mark a line pointing north from the city point.

With the Students

  1. Introduce the students to the Skywatch1 website.
  • Click on Start Java Applet.
  • Enter your city (or closest city) under Observer Location.
  • Notice how Skywatch automatically adjusts to your latitude, longitude, and altitude.
  1. Click on Next Sighting to track the next observable path of the ISS.
  • You may have to click Next Sighting more than once if it is more than 1 week away.
  1. Find the day, or night, of interest and have the students print out the predicted points of travel by hitting the Print button.
  2. Ask students what questions they have about the print out.
  3. Assign each group a different point to model.
  4. One group at a time can model the ISS around the city point.
  5. Each group should cut a length of string corresponding to the range scaled down by 10 and in inches. For example, if the range was 749 miles, the string would be cut to 74.9 inches long.
  6. Have one student in the group hold one end of the string to the city point while a second student holds the other end along the ground facing north. The second student should always have the string pulled tight.
  7. The first student should direct the second student to move clockwise around the city and stop when the azimuth is met. For example, if the azimuth is 180°, the second student will have moved in a half circle and be directly south of the city point.
  8. Next, using a protractor located at the city point, the first student should instruct the second student to raise the string until the elevation is met.
  9. While the second student carefully holds the azimuth and elevation, a third student should measure and record the height and location of the end of the string. This can be done by taping a piece of paper on the ground under the end of the string, marking an X beneath the end, and writing down how high it was next to the X.
  10. Finally, when all the groups have marked their Xs and heights, the teacher or designated students should hang a foam ball over each X according to its height. In the end, you should have a 3-D model of the ISS path.
  11. Ask two groups to volunteer to present the model to the rest of the class.

1 http://spaceflight.nasa.gov/realdata/sightings

2 http://www.dransom.com/

3 http://spaceflight.nasa.gov/realdata/sightings

Troubleshooting Tips

Make sure the day of interest has a maximum elevation of significance. Any max elevation less than 60° will result in a less than impressive looking model.

If you have too many data points, click on Variables and raise the Table Step Size to 30 or 40 seconds then recalculate your day of interest.

If you feel the model is too low to the ground, add 5 feet (1.5 m) to every height to shift the model towards the ceiling.


Pre-Activity Assessment

Matching: Have students "match" terms to definitions to assess their mastery of the subject.

  • Write the terms and the definitions of the three concepts listed below on six separate pieces of paper. Ask for six volunteer students to come up to the front of the room, and give each one of them a piece of paper. Have all volunteers read what is written on their papers one at a time. Have the audience match term to definition by voting. Have student "terms" stand by their "definitions." At the end, give a brief explanation of concepts.

Azimuth – the number of degrees measured clockwise from the north horizon.

Elevation – the height, in degrees, above the horizon.

Range – the distance from where you are located to a spacecraft or satellite.

Activity Embedded Assessment

Brainstorming: In small groups, have the students engage in open discussion. Remind students that no idea or suggestion is "silly." All ideas should be respectfully heard. Ask the students:

  • How could a satellite track be traced without computer software? (Possible answers: Extremely hard to track them, manually, with other satellites sending data to a central office.)
  • Why do mission managers and engineers want to track satellites? (Possible answers: to predict when they will fall to Earth; to make sure they remain in their correct orbits.)

Post-Activity Assessment

Presentation: Ask two groups to present their models to the rest of the class. Discuss the 3-D model as a whole.


Skywatch program website: http://spaceflight.nasa.gov/realdata/sightings>

STSPlus program website: http://www.dransom.com/


Penny Axelrad; Janet Yowell; Malinda Schaefer Zarske


© 2004 by Regents of the University of Colorado.

Supporting Program

Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder


The contents of this digital library curriculum were developed under a grant from the Satellite Division of the Institute of Navigation (www.ion.org) and National Science Foundation GK-12 grant no. 0338326. 

Last modified: August 10, 2017