Ball Aerospace and the Naval Research Laboratory designed and built the Oriented Scintillation Spectrometer Experiment (OSSE) as one of four instruments aboard the Compton Gamma Ray Observatory.

As part of the second of NASA’s four Great Observatories, OSSE gathered data to answer questions such as how elements are created in supernovae explosions, how massive stars collapse to form black holes and liberate massive amounts of energy, and where and how positrons are produced in our galaxy.

The OSSE instrument consisted of four gamma ray scintillation detectors that rotated to look at different parts of the sky in the energy range of 50 keV to 10 MeV. The energy that cosmic gamma rays carry has provided us with important information about the temperature, structure, and chemical composition of objects radiating these rays. OSSE captured the glow of gamma radiation from the disk of the Milky Way Galaxy.

OSSE data offered the possibility that there may be an entirely new type of celestial body from either unexplained sources relatively near the solar system or from immensely powerful unknown objects in deep space. In 1991, OSSE recorded a series of record-breaking bright solar flares that may help researchers deduce the relative abundance of elements in the lower layers of the sun’s atmosphere.

Designed to last at least two years, OSSE launched with the Compton Gamma Ray Observatory in April 1991 and returned to Earth in 2000.