COSMIC consists of a network of satellites, ground stations and data centers.
Launched on April 14, 2006 on a single Minotaur rocket, the "constellation" of six cylindrically shaped COSMIC microsatellites took between one to two years to reach operational altitude and position [sources: COSMIC Web site, Fong]. Each satellite weighs around 110 pounds (70 kilograms) and measures about 46 inches (116 centimeters) wide and 7 inches (18 centimeters) high, and each one carries the same set of three instruments on board. We'll cover those instruments and what they do a little bit later, but generally speaking, these satellites make detailed measurements across the atmosphere every day.
COSMIC satellites are in a polar orbit, meaning that during each trip around the planet they pass over both poles. Separated by 30 degrees of longitude and operating at about 500 miles (800 kilometers) above the planet, the satellites together are optimized to cover the entire surface of the Earth as often as possible [source: Anthes].
Because the mission approach is new and limited to six satellites, technical problems sometimes arise. At any one time, several of the satellites are experiencing low power or other technical issues, limiting their functionality and the number of observations the instruments on board can make. The projected life of the satellites is five years [source: Fong].
Data transmitted from the satellites is collected by ground stations in Alaska, Virginia, Norway and Antarctica, with most of the downloading taking place in Alaska and Norway [source: Hunt]. These ground stations then relay the information to the data centers. The Multi-Mission Center (MMC) located in Taiwan controls the movement of the satellites themselves [source: Schreiner].
The data received by the ground stations is forwarded to the data centers in Taiwan and Boulder. In the United States, the data center is called the COSMIC Data Analysis and Archive Center (CDAAC), where a staff of 10 processes and distributes mission data to the scientific community.
But what data are actually collected, and how is this done? The next page explains just what's on board each COSMIC satellite.