DMSP 5D-2 was the military's sixth generation of weather satellites. The DMSP 5D-2 satellites operated in two-satellite constellations to provide world-wide meteorological, oceanographic and solar-terrestrial physics measurements on a twice-daily basis. The visible and infrared sensors collected images of global cloud distribution across a 3,000 km swath during both daytime and night time conditions.

The coverage of the microwave imager and sounders were one-half the visible and infrared sensors coverage, covering the polar regions above 60 deg on a twice-daily basis, but the equatorial region on a daily basis. The space environmental sensors recorded along-track plasma densities, velocities, composition and drifts. The spacecraft was based on the GE Tiros bus and 3-axis stabilized using reaction wheels and torque rods to within 0.01 deg. The hydrazine propulsion system was used for orbit insertion, a nitrogen propulsion system for stationkeeping. Star sensors and gyros provided 0.01 deg. knowledge. An Earth sensor and sun were sensor carried as backups. Data was stored on a tape recorder. The solar array generated 900 W (BOL) and recharged NiCd batteries with 30 AHr capacity. S-band communications were via 5 W RF, 5 MHz bandwidth, omni antennas. The satellites were controlled from Offutt AFB, Nebraska with terminals at Loring AFB, Maine; Fairchild AFB, Washington; and AFRTS Hawaii. The payload mass of 110 kg, included:

• Operational Linescan System (OLS) - visible/infrared imager
• SSM/T - atmospheric sounder producing cloud temperature profiles
• SSM/I - microwave imager measuring ice coverage, precipitation areas and intensities, cloud water content, ocean surface wind speeds
• SSB/X2 - gamma and x-ray spectrometer
• SSJ/4 - measured proton and electron densities
• SSM - magnetometer.

  The R&D cost for DMSP 5D-2 was $ 7.6 million. The first joined 5 earlier generation DMSP's still operating in orbit. Launch of 8 more continued through 1997.

  Design Life: 3 years. Typical orbit: Typically 820-860 km, polar, sun-synchronous, 6 am. Length: 3.40 m (11.10 ft). Maximum Diameter: 1.20 m (3.90 ft). Mass: 770 kg (1,690 lb). Associated Launch Vehicle: Atlas E, Titan 2.

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  DMSP Block 5D-2 Chronology
  • 1982 December 21 - AMS 5 - Program: DMSP. Launch Site: Vandenberg. Launch Vehicle: Atlas E. Mass: 750 kg (1,650 lb). Perigee: 797 km (495 mi). Apogee: 810 km (500 mi). Inclination: 98.60 deg. Period: 100.90 min.

    Defense Meteorological Satellite Program.

  • 1983 November 18 - DMSP B5D2-2 - Program: DMSP. Launch Site: Vandenberg. Launch Vehicle: Atlas E. Mass: 750 kg (1,650 lb). Perigee: 801 km (497 mi). Apogee: 818 km (508 mi). Inclination: 98.40 deg. Period: 101.10 min.

    Defense Meteorological Satellite Program.

  • 1987 June 20 - USA 26 - Program: DMSP. Launch Site: Vandenberg. Launch Vehicle: Atlas E. Mass: 750 kg (1,650 lb). Perigee: 828 km (514 mi). Apogee: 848 km (526 mi). Inclination: 98.80 deg. Period: 101.70 min.

    Defense Meteorological Satellite Program.

  • 1988 February 3 - USA 29 - Program: DMSP. Launch Site: Vandenberg. Launch Vehicle: Atlas E. Mass: 750 kg (1,650 lb). Perigee: 807 km (501 mi). Apogee: 817 km (507 mi). Inclination: 98.50 deg. Period: 101.10 min.

    Defense Meteorological Satellite Program.

  • 1990 December 1 - USA 68 - Program: DMSP. Launch Site: Vandenberg. Launch Vehicle: Atlas E. FAILURE: Failure of the spacecraft's TEM-364-15 AKM nozzle due to a manufacturing defect led to the satellite being placed into lower than planned orbit. Mass: 750 kg (1,650 lb). Perigee: 724 km (449 mi). Apogee: 837 km (520 mi). Inclination: 98.70 deg. Period: 100.50 min.

    Defense Meteorological Satellite Program; broken nozzle prevented satellite from reaching desired orbit.

  • 1991 November 28 - USA 73 - Program: DMSP. Launch Site: Vandenberg. Launch Vehicle: Atlas E. Mass: 830 kg (1,820 lb). Perigee: 835 km (518 mi). Apogee: 852 km (529 mi). Inclination: 99.00 deg. Period: 101.80 min.

    Defense Meteorological Satellite Program. 500th Atlas launch.

  • 1994 August 29 - USA 106 - Program: DMSP. Launch Site: Vandenberg. Launch Vehicle: Atlas E. Mass: 830 kg (1,820 lb). Perigee: 840 km (520 mi). Apogee: 860 km (530 mi). Inclination: 98.89 deg. Period: 101.94 min.

    Defense Meteorological Satellite Program.

  • 1995 March 24 - USA 109 - Program: DMSP. Launch Site: Vandenberg. Launch Vehicle: Atlas E. Mass: 750 kg (1,650 lb). Perigee: 845 km (525 mi). Apogee: 854 km (530 mi). Inclination: 98.80 deg. Period: 101.90 min.

    Last successful Atlas E space launch.

  • 1997 April 4 - USA 131 - Program: DMSP. Launch Site: Vandenberg. Launch Vehicle: Titan 2. Perigee: 842 km (523 mi). Apogee: 855 km (531 mi). Inclination: 98.90 deg. Period: 101.90 min.

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  Bibliography and Further Reading
  • Krebs, Gunter, Gunter's Space Page, University of Frankfurt, 1996. Accessed at: http://www.skyrocket.de/space.
  • USAF Satellite Database, USAF Institute of Technology, 1995. Accessed at: ftp://archive.afit.af.mil/pub/space/.
  • McDowell, Jonathan, Jonathan's Space Report (Internet Newsletter), Harvard University, Weekly, 1989 to Present. Essential internet newsletter recording worldwide weekly space events. Accessed at: http://www.planet4589.org/jsr.html.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Accessed at: http://msl.jpl.nasa.gov/home.html.
  • Lockheed Martin Coporation, Atlas Family Fact Sheets, September 1998.. Accessed at: http://www.lmco.com/ILS/txtmain/ils_lsysinfo.htm.
  • McDowell, Jonathan, Jonathan's Space Home Page, Harvard University, 1997-present. Jonathan McDowell's complete on-line listing of all objects orbited and over 20,000 rocket launches Accessed at: http://www.planet4589.org/jsr.html.