This database accesses the FITS lightcurves obtained from the A detector part of the GSFC Cosmic X-ray Spectroscopy experiment (GCXSE) on board OSO8. The Orbiting Solar Observatory-I (OSO-8) was launched on 21 June 1975 into a 550 km circular orbit at 33 degrees inclination. While the primary objectives of the mission were solar in nature, there were 3 detectors (the GCXSE detectors A, B and C) which had exclusively non-solar objectives. The energy band was 2-60 keV for the A and C detector and 2-20 keV for the B detector. The spacecraft structure consisted of a rotating cylindrical base section called the "wheel" and a non-spinning upper section called the "sail". The GCXSE detectors were mounted in the rotating wheel and their fields-of-view were either aligned to the spin axis (B and C) or at small angles to it (A), hence they always viewed the portion of the sky at right angles to the earth-sun line. The GCXSE detectors obtained data until late September 1978. This is a service provided by NASA HEASARC .

Copernicus was the third satellite in the OAO program. It was launched the 21 august of 1972 and operated till 1981. The main instrument was an ultraviolet telescope with a spectrometer to measure interstellar absorption lines in the spectra of stellar objects. However it carried also an X-ray experiment provided by University College of London/MSSL consisted in 4 co-aligned experiments sensitive in the 1-10 keV energy range. This database accesses the raw FITS file containing data obtained from the UCL X-ray Experiment (UCLXE) package on board Copernicus. This is a service provided by NASA HEASARC .

The UCSD/MIT Hard X-Ray and Low-Energy Gamma-Ray Instrument, A4, was flown on the HEAO 1 satellite, between August 1977 until January 1979. The experiment consisted of a collection of collimated sodium iodide scintillators, two of which the Low Energy detectors (LED, LED-3 and LED-6), were optimized for the lower energy part of the hard X-ray range between 13 to 180 keV. The first 6-months of mission were dedicated to an all-sky scan after which a pointing phase started. In pointing mode the A4-LED instrument look axis was kept in a 1 deg dead band centered on the target position. Instead in the "ping-pong" mode the look axis was regularly alternated with a secondary target a few degrees away, usually for background determination. This database table accesses the spectra (and associated files) obtained from the A4-LED detectors in the ping-pong mode. This is a service provided by NASA HEASARC .