Defense Meteorological Satellite Program

Rendering of lights on Earth's surface created using DMSP observations

During the 1960s, one of the most important projects that the United States civil space program was involved in dealt with meteorology and weather forecasting. Unbeknownst to many, the U.S. military services were also starting up a weather satellite program. This program, the DMSP, would relay important weather and climate data to the military for more effective operations. From the onset of the DMSP program, knowledge of its existence was limited to "need-to-know" personnel. The United States Congress had assigned a substantial budget towards the civil weather satellite program; if knowledge of a second military program came out, it would have been hard for the military to justify it.

Initial operations of early DMSP systems provided radio return of cloud-cover imagery for planning of U.S. high-resolution photographic reconnaissance and surveillance missions, which utilized film-return systems. DMSP satellites operated in a Sun-synchronous orbit; passing over the north and south poles, the satellite would see different strips of the Earth at the same local time each day. The DMSP satellites had periods of roughly 101 minutes, so they would orbit the Earth 14.3 times in 24 hours. This period combined with the Sun-synchronous orbit would have the satellite pass over the whole surface of the planet twice a day.

DMSP and POES orbits shown in a GAO diagram.

The images acquired were relayed to the Earth and received by two command and readout stations established at retired Nike missile sites located near Fairchild Air Force Base in Washington State and Loring Air Force Base in Maine.[3] From these sites, the images were then sent to Air Force Global Weather Central (AFGWC) located at Offutt Air Force Base, Nebraska. Images would then be processed, forming a mosaic representing the cloud patterns that were observed from the orbiting satellites. Meteorologists could then provide flight crews and other commanders with up-to-date observations for their particular missions. Further advancements enabled data to be collected in the visual spectrum down to a half-moonlit scene. Infrared processing enabled night viewing. Other enhancements increased on-board processing; this includes multiple on-board computers and expanded power requirements.

Now in its fifth decade of service, the DMSP program has proven itself to be a valuable tool in scheduling and protecting military operations on land, at sea, and in the air. In December 1972, DMSP data was declassified and made available to the civil scientific community. On June 1, 1998 the control and maintenance of the satellites were transferred to National Oceanic and Atmospheric Administration (NOAA) in order to reduce costs.[4]

DMSP was to be replaced by the Defense Weather Satellite System but that was cancelled in 2012. In 2017, the Air Force awarded a contract to build the first of the new defense weather satellites, the Weather System Follow-on Microwave (WSF-M) satellite.[5]

DMSP was initially known as Program 35. The first successful launch of a Program 35 spacecraft used a Scout X-2 rocket lifting off from Point Arguello near Vandenberg Air Force Base on August 23, 1962.[11][12] This was P35-2; the earlier P35-1 launch on May 24, 1962 had failed to reach orbit.[13] All five Program 35 launch attempts using Scout rockets, including the two successes, were made from Vandenberg SLC-5. Other early launches were conducted using Thor launch vehicles, with Altair or Burner II upper stages. Program 35 had by this time been renamed the Data Acquisition and Processing Program, and the DAPP acronym is sometimes used for these satellites.[14] Eight satellites were launched using Atlas E launch vehicles between 1982 and 1995. Three were launched aboard Titan II vehicles between 1997 and 2003. One has been launched on a Delta IV rocket.

The most recent launch of a DMSP satellite, DMSP-F19, occurred on April 3, 2014, from Vandenberg aboard an Atlas V rocket.[15]

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  DMSP - Block 5D2
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  DMSP - Block 5D2
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  DMSP - Block 5D1
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  DMSP Shroud at SLC-10
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  FAIR Operations room ca. 1977

• NPOESS - the National Polar-orbiting Operational Environmental Satellite System

• Space debris

• R. Cargill Hall - A History of the Military Polar Orbiting Meteorological Satellite Program
• National Geophysical Data Center archive of DMSP data
• Air Force Fact Sheet (dead-link)
• The High Ground - DMSP (dead-link)
• Air Force Research Lab Horizons magazine article
• Air Force news article
• SSIES ionospheric instrument data page