Defense Meteorological Support Program [DMSP]

DMSP, originally known as the Defense System Applications Program (DSAP) and the Defense Acquisition and Processing Program (DAPP), is a long-term USAF effort in space to monitor the meteorological, oceanographic and solar-geophysical environment of the Earth in support of DoD operations. All spacecraft launched have had a tactical (direct readout) and a strategic (stored data) capacity. In December 1972, DMSP data was declassified and made available to the civil/scientific community. The USAF maintains an operational constellation of two near-polar, sun-synchronous satellites. The DMSP mission is to provide global visible and infrared cloud data and other specialized meteorological, oceanographic and solar-geophysical data in support of world wide Department of Defense (DoD) operations.

DMSP satellite command and control is performed by the 6th Satellite Operations Group at Offutt AFB, Nebraska. Data is transmitted in real time to tactical terminals world-wide. Data is also stored using on-board recorders for transmission to and processing by the Air Force Global Weather Central (AFGWC), Offutt AFB, Nebraska and the Fleet Numerical Meteorology and Oceanography Center (FNMOC), Monterey, California. Both AFGWC and FNMOC relay the SSM/I, SSM/T and SSM/T2 data to the National Environmental Satellite, Data, and Information System (NESDIS). AFGWC also sends the entire data stream to the National Geophysical Data Center (NGDC).

Meteorological satellites were developed and operated by the Air Force under the Defense Meteorological Satellite Program (DMSP). This program, previously known as DAPP (Data Acquisition and Processing Program), was classified until March 1973. The first DMSP satellites were developed by a program office physically located with Space Systems Division but reporting to the National Reconnaissance Office (NRO), which needed analyses of cloud cover over Eurasia to plan its photographic reconnaissance. The program office awarded a development contract for weather satellites employing television cameras to RCA in 1961.

DMSP Block I began with five launch attempts on Scout launch vehicles during 1962 and 1963, all but one of which failed. Later Block I launches on Thor Agena and Thor Burner I vehicles were more successful. Two launches in 1964 using Thor Agena vehicles placed two Block I satellites in orbit during each launch and provided enough weather imagery for strategic purposes for the first time. Six launch attempts during 1965 and 1966 employed a new Thor upper stage known as Burner I for DMSP payloads, including two more Block I, three Block II, and one Block III.

Besides providing weather information for strategic purposes, early DMSP satellites also provided the earliest tactical uses of space-based weather information. A Block I satellite launched on 18 March 1965 secretly provided weather data for North and South Vietnam to a ground station at Tan Son Nhut Air Base in Saigon. This was the world’s first use of satellite imagery to support tactical military operations. The Block II satellites were also modified for direct readout of meteorological data so that they could be used for planning tactical air operations in Southeast Asia while continuing to provide weather information for strategic reconnaissance. The single Block III satellite, launched in 1965, was equipped only for tactical uses in Southeast Asia.

Wider military uses for weather data led to an important change in the program’s reporting structure when, on 1 July 1965, it became a program office under Space Systems Division. Development of more capable and more complex satellites also came to fruition with DMSP Block 4 satellites, seven of which were launched during 1966-1969. Television resolution improved from 3 to 4 nautical miles with Blocks I and II to 0.8 to 3 nautical miles with Block 4, along with many other improvements in the sophistication of secondary sensors.

Block 5A satellites introduced the Operational Line Scan (OLS) sensor, which provided images of clouds in both visual and infrared spectra. Television resolution improved to 0.3 nautical miles in daylight. Three Block 5A, five 5B, and three 5C satellites were launched during 1970- 1976 on Thor Burner II launch vehicles. Larger and much more sophisticated Block 5D-1 satellites were also developed during the 1970s, but only five were built. This proved to be a mistake in 1980, when the fifth 5D-1 satellite was lost in a launch failure, and the operational 5D-1 satellites in orbit ceased to function prematurely. From August 1980 to December 1982, when the first Block 5D-2 satellite was successfully launched, meteorological data was supplied to DOD entirely by civilian satellites. That mistake was not repeated with Block 5D-2 satellites, nine of which were launched during 1982-1997 on Atlas E and Titan II launch vehicles.