HEAO (High Energy Astrophysics Observatory)
A series of three very large scientific satellites launched by NASA, beginning
in 1977, to carry out detailed observations of the sky at short wavelengths,
from ultraviolet to gamma rays.
An X-ray astronomy satellite that surveyed the sky in the 0.2 keV–10
MeV energy band, providing nearly constant monitoring of X-ray sources near
the ecliptic poles. More detailed studies of a number of objects were made
through pointed observations lasting typically 3–6 hours. The spacecraft
remained active until Jan. 9, 1979.
The first fully imaging X-ray telescope to be placed in orbit; later renamed
the Einstein Observatory to honor the centenary of the great physicist's
birth. Its angular resolution of a few arcseconds, field-of-view of tens
of arcminutes, and sensitivity several hundred times greater than any previous
mission provided, for the first time, the capability to create images of
extended objects and diffuse emission and to detect faint sources at such
high energies (0.2–4.5 keV). It revolutionized astronomers' view of
the X-ray sky. Observations ceased in April 1981.
Like its predecessor HEAO-1, a survey mission operating in the hard X-ray
and gamma-ray (50 keV-10 MeV) band. Its High Resolution Gamma-Ray Spectrometer
Experiment, built by JPL (Jet Propulsion Laboratory), was the largest germanium
spectrometer placed in orbit at that time. The mission effectively ended
when the cryogenic coolant for the germanium detectors ran out in May 1981.
All the HEAO's were launched by Atlas Centaur
SLV-3D's from Cape Canaveral.
||Aug. 12, 1977
||429 × 447 × 22.7°
||Nov. 12, 1978
||526 × 548 × 23.5°
||Sep. 20, 1979
||487 × 503 × 22.7°
AND SPACE PROBES