Artist's impression of a Defense Meteorology Satellite Programme (DMSP) Block 5D-2 satellite. The DMSP satellites provide military users with meteorology data. In addition to providing weather forecasting data for military purposes, DMSP can determine whether or not cloud cover will affect the operation of reconnaissance and surveillance satellites. More than 30 DMSP satellites have been launched under a variety of code names since the 1960s. To date, four of the Block 5D-2 models have been launched, with a further five planned.