Mission Overview

The European Space Agency's X-ray Observatory, EXOSAT, was operational from May 1983 to April 1986. During that time, EXOSAT made 1780 observations of a wide variety of objects, including active galactic nuclei, stellar coronae, cataclysmic variables, white dwarfs, X-ray binaries, clusters of galaxies, and supernova remnants.

Lifetime: May 26, 1983 - April 9, 1986
Energy Range: 0.05-50 keV
Special Features: 90 Hours highly-eccentric Earth orbit

Launch Information

Launch Date: 1983-05-26 at 15:18:00 UTC
Launch Vehicle: Delta 3914
Launch Site: Vandenberg AFB, United States
Decay Date: 1986-05-06

Trajectory Description
Type: Orbiter
Central Body: Earth
Epoch start: 1983-05-26 15:18:00 UTC

Orbital Parameters
Periapsis 347.0 km
Apoapsis 191709.0 km
Period 5435.39990234375 minutes
Inclination 72.5°
Eccentricity 0.934283971786499


• 2 Wolter Type I grazing incidence Low Energy (LE; 0.05-2 keV) Imaging Telescopes, FOV ~ 2°, peak effective area 10 cm2 each with
   o Channel Multiplier Array (CMA; 0.05-2.0keV) eff. area 0.4 - 10 cm2, FOV ~2°, ~18 arcsecond spatial resolution
   o Position Sensitive Detector (PSD)
   o Transmission Gratings (TGS) 500 lines mm-1(LE2), 1000 lines mm-1(LE1). Used in conjunction with the CMA detectors.
• A Medium Energy (ME) Proportional Counter 1-50 keV, FOV 45 arcmin, 1600 cm2
• A Gas Scintillation (GS) Proportional Counter 2-20 keV, 100 cm2


• Discovery of the Quasi Period Oscillations in LMXRB and X-ray Pulsars
• Comprehensive study of AGN variability
• Observing LMXRB and CV over many orbital periods
• Measuring iron line in galactic and extra galactic sources
• Obtaining low-energy high-resolution spectra