Mission Overview

The Kvant 1 module (Kvant means 'quantum' in Russian) was launched on 31 March 1987 and attached to the Mir space station on 12 April 1987. After that, the Mir-Kvant observatory successfully operated until fall 1989, at which time operation was stopped for a planned reconfiguration of the Mir station. Kvant was “restarted” in October 1990 with calibration observations showing no apparent degradation in performance from the year off. There were 4 high-energy instruments in the module: TTM/COMIS - a coded mask imaging spectrometer, HEXE - a set of 4 scintillators, GSPC - a scintillation proportional counter, and Pulsar X-1 - a set of 4 scintillators. All 4 experiments pointed toward the same source at the same time. These experiments, taken together, were sometimes referred to as the RÖNTGEN Suite or Observatory.

The orbital period of the Mir station was 90 minutes. At an inclination of 57 degrees, some 20 minutes of each orbit of each orbit were spent outside the radiation belts. Spacecraft stabilization over a 20 minute period was better than 2 arcminutes. The Kvant module was 19 feet long and 13.6 feet across at its widest point. A cosmonaut controlled the observations from a pressurized cabin inside the module. The mission ended when Mir reentered the atmosphere in March 2001.

Lifetime: February 5, 1987 - November 1, 1991. Energy Range: 1 - 500 keV.

Launch Information

Launch Date: 1987-03-31 at 00:16:16 UTC
Launch Vehicle: Proton Booster Plus Upper Stage
Launch Site: Tyuratam (Baikonur Cosmodrome), U.S.S.R
Decay Date: 2001-03-23

Trajectory Details
Type: Orbiter
Central Body: Earth
Epoch start: 1987-03-31 00:00:00 UTC

Orbital Parameters
Periapsis 177.0 km
Apoapsis 320.0 km
Period 89.19999694824219 minutes
Inclination 51.599998474121094°
Eccentricity 0.010781999677419662


TTM/COMIS was a wide-angle camera that uses a coded aperture mask to determine source location. It covered the energy range 2-30 keV with a 7.8 deg x 7.8 deg field of view FWHM. The geometric area was 655 cm2. It achieved an angular resolution of 2 arcminutes and a time resolution of 1 s. The Galactic center region was imaged with the TTM demonstrating the efficiency of coded mask telescopes observations in hard X-rays. HEXE, or High Energy X-ray Experiment, employed a phoswich of sodium iodide and cesium iodide. It covered the energy range 15-200 keV with a 1.6 deg x 1.6 deg field of view FWHM. Each of the 4 identical detectors had a geometric area of 200 cm2. The maximum time resolution was 0.3-25 ms.

GSPC, also called Sirene 2, was a gas scintillation proportional counter. It covered the energy range 2-100 keV with a 3 deg x 3 deg field of view FWHM. The detector geometric area was 300 cm2. The instrument had a maximum time resolution of 1.25-2.5 ms.

Pulsar X-1 consisted of 4 phoswich detectors which covered the energy range 50-800 keV with a 3 deg x 3 deg field of view FWHM. Each of the 4 identical detectors had a 314 cm2 geometric area. The maximum time resolution was 10 s.

Astro-C, renamed Ginga (Japanese for 'galaxy'), was launched from the Kagoshima Space Center on 5 February 1987. The primary instrument for observations was the Large Area Counter (LAC). Ginga was the third Japanese X-ray astronomy mission, following Hakucho and Tenma. Ginga reentered the Earth's atmosphere on 1 November 1991.

• Large Area Proportional Counter (LAC) 1.5-37 keV Eff. area = 4000 cm2, FOV = 0.8° x 1.7°

• All-Sky Monitor (ASM) 1-20 keV Eff. area = 70 cm2, FOV = 1° x 180°

• Gamma-Ray Burst Detector (GBD) 1.5-500 keV Eff. area = 60 cm2 (SC) and 63 cm2 (PC), FOV = All-sky

• Discovery of transient Black Hole Candidates and study of their spectral evolution.

• Discovery of weak transients in the galactic ridge.

• Detection of cyclotron features in 3 X-ray pulsars: 4U1538-522, V0332+53, and Cep X-4.

• Evidence for emission and absorption Fe feature in Seyfert probing reprocessing by cold matter.

• Discovery of intense 6-7 keV iron line emission from the galactic center region.