OSO-1 launch cover. Credits: Colorado State University

Launched on March 7, 1962, OSO-1 was the first of 8 Orbiting Solar Observatories developed for the long-term study of the sun. The Mission of the OSO satellites was to return data on the ultraviolet, X-ray and gamma ray emissions of the sun and Milky Way galaxy. At the time, it was the most complex object launched into space.

Left: OSO-1 Satellite specs. Right: OSO-1 under construction

The scientific instruments aboard the OSO-1 featured a design that permitted various instruments to be pointed accurately at the sun while others scanned the galaxy for scientific data. The OSO satellites made the first orbital observations of the solar corona and complex solar magnetic fields, providing important data on their relationship to solar activities.

Left: OSO-1 Satellite specs. Right: OSO-1 under construction

OSO-1 performed well until its second onboard tape recorder failed on May 15, 1962. OSO-1 continued to transmit real-time solar measurements until May of 1964, when its solar cells failed and lost power. It would continue to orbit the Earth for another 17 years, re-entering the Earth’s atmosphere on October 8, 1981, burning up upon re-entry.