The DMSP spacecraft are a series of vehicles built and launched since the 1960's under the direction of the Air Force Space Division for the Air Force Global Weather Central, Offutt AFB, NE as a service to the DoD community. The prime sensor for the spacecraft is the Operational Line Scan (OLS) system which makes high-resolution white-light and infra-red images of the earth's cloud systems. Other instruments which measure the troposhperic and space environment are included as payload capacity and operational needs allow.

The DMSP spacecraft are launched into an 832 km, 98. 7 degree inclination circular orbit. The non-spherical terms of the earth's gravity field cause the orbit plane to precess so that the orbit plane always has the same orientation with respect to the Earth-Sun line; i.e., the orbit is sun-synchronous. The DMSP spacecraft have a planned lifetime on orbit of three years. Two functioning DMSP spacecraft are supposed to be on orbit at all times: one in the 6:00-18:00 meridian plane and one in the 10:30-22:30 meridian plane (often referred to as a noon- midnight orbit.