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Teal Ruby

Experimental Early Warning Sensor

This satellite, known as spacecraft P80-1, carried an experimental infrared telescope code named “Teal Ruby.” Designed to detect heat, Teal Ruby was meant to give early warning of enemy aircraft crossing the polar region toward the United States during the Cold War.

The Teal Ruby telescope is inside the white barrel-shaped object facing the forward end of the museum's Space Shuttle Exhibit. Along with the telescope, the graphite epoxy barrel houses gyroscopes, cooling equipment and electronics. In the late 1970s, Teal Ruby featured new technology, now used in digital cameras, enabling it to continuously image large areas for long periods.

The Teal Ruby telescope aboard P80-1, along with other experiments, was to be launched on a space shuttle in the 1980s. However, the U.S. Air Force cancelled the project due to high costs, technology issues and complications following the Space Shuttle Challenger accident. Instead, spacecraft P80-1 became a test-bed for studying how space equipment ages in storage.

Along with detecting aircraft from space, Teal Ruby had other capabilities. It was also projected to conduct ocean surveillance to target ships, provide missile launch warning, detect other satellites, and see major events on the Earth’s surface.

The USAF and the Defense Advanced Research Projects Agency (DARPA) sponsored the Teal Ruby project. Rockwell International Corp. developed the Teal Ruby telescope.

Air Force-NASA Partnership in Teal Ruby Technology

The USAF and NASA Lewis (now Glenn) Research Center, Cleveland, OH, worked together on important aspects of spacecraft P80-1, which was to carry the Teal Ruby sensor and other experimental equipment. One system that NASA Glenn developed was a series of small thrusters that would help keep the satellite in precise position in orbit. Known as the Ion Auxiliary Propulsion System (IAPS), these electric thrusters used mercury as a propellant. The mercury was accelerated by bombarding it with electrons, creating ions travelling at 60,000 mph and providing thrust. This method featured increased power and significant weight savings over more traditional chemical-combustion thrusters, and allowed additional instruments to be carried aboard satellites.

NASA Lewis performed many hours of successful tests on the thrusters, and Wright-Patterson AFB laboratories hosted several tests. Endurance trials included more than 15,000 hours of operation on a laboratory ion thruster model. Following this successful testing, IAPS thrusters were installed on the Teal Ruby spacecraft.

Learn more about ion propulsion from NASA at

Infrared, cryogenically cooled to -375 degrees F, four mirrors, f/3.3, focal length 66 inches
Orbit: Intended to be circular, altitude 414 miles (low earth orbit), 72 and later 57 degree inclination from the equator
Weight: P80-1 spacecraft 5,160 lbs., Teal Ruby telescope 61 lbs.

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