or Bragg Focal Plane Crystal Spectrometer, as well as a 1-20 keV Monitor Proportional Counter (MPC), a Broad Band Filter Spectrometer (BBFS), and an objective grating spectrometer (OGS). The observatory re-entered the Earth's atmosphere and burned up on March 25, 1982. HEAO 3 HEAO 3, launched on 20 September 1979 into a 43.6-degree inclination orbit, carried three experiments, known as C1, C2, and C3. The first was a cryogenically cooled germanium (Ge) high-resolution gamma-ray spectrometer, while the C2 and C3 experiments were large cosmic-ray instruments. The satellite re-entered the Earth's atmosphere and burned up on December 7, 1981. Program The experiment designations A1, A2, A3, A4, for HEAO A, thru C1, C2, C3 for HEAO C, were most common before launch, but also often appear in the later scientific literature. The overall HEAO program was managed out of NASA's Marshall Space Flight Center in Huntsville, AL. NASA Program Manager was Mr. Richard E. Halpern; NASA Program Scientist was Dr. Albert G. Opp. All three satellites were built by TRW Systems of Redondo Beach, California, who won the Nelson P. Jackson Aerospace Award for their work. The total program cost was roughly $250 million. See also HEAO 1 HEAO 2 HEAO 3 References NASA programs Space telescopes TRW Inc.