The US Air Force has responsiblity for a program called the Defense
Meteorological Satellites Program (DMSP) since the mid-1960s. They have
launched a series of spacecraft to investigate the Earth's environment from an
altitude of ~800 km. They were all put into Sun-synchronous near-polar
orbits (inclination ~ 99 degrees). Of interest to the high-energy science
community are DMSP 8, 9, 10, 11, 12, 13, 14 and 15.
DMSP 8 was launched 20 June 1987; last data were returned on 1 August 1994.
DMSP 9 was launched 3 February 1988; last data were returned on 3 April
1992. DMSP 10 was launched 1 December 1990; last data were returned on 26
September 1994. DMSP 11 was launched 28 November 1991; first data were
returned 6 December 1991. DMSP 12 was launched 29 August 1994; first data were
returned 8 September 1994. DMSP 13 was launched 24 March 1995;
DMSP 14 was launched on 4 April 1997 and DMSP 15 on 12 december 1999.
On-board each spacecraft were/are 2 gamma-ray detectors, each with ~ 100 sq-cm
detection area of NaI and charged particle shields. While passing through
the outer Van Allen belts 4 times each orbit, and often through the South
Atlantic Anomaly as well, led to a very high background, there were still
long periods in each orbit in which cosmic gamma-ray events could be
Several gamma-ray bursts have been reported in the data from DMSP satellites.
Many of the bursts were also seen by other satellites, e.g. PVO, Ulysses, and
CGRO. Now the DMSP satellites are part of the Interplanetary Network,
IPN3, designed to localize Gamma-ray burst.