NASA / SCIENCE PHOTO LIBRARY NASA / SCIENCE PHOTO LIBRARY
Model of the Defense Support Program (DSP) satellite launched by Shuttle Mission STS-44 in November 1991. DSP is designed to be the space- bourne segment of the USA's early warning system. Its infrared detector (tube at top right) is able to sense the heat from missile plumes against the Earth's background, and thus detect missile launches. It is also able to detect nuclear detonations. The first DSP satellites were launched in the early 1970s, the latest is 2 1/2 times the weight of the first (now 1,300kg), and has 3 times the number of detector elements (now 6,000). The design life is 5 years.
Model release not required. Property release not required.