An international scientific research program, called Mission to Planet Earth, isbeing planned as a 25-year effort. It will use a new, integrated network of Earth satellitesto understand how the atmosphere, seas, and living creatures function togetheras a single global system. Mission to Planet Earth will include three groups of satellitescarrying a broad array of remote sensing instruments. Satellites in polar orbit will scanthe Earth as it turns beneath. Those in geosynchronous orbit, fixed in position relativeto the Earth, will stare at limited areas. Earth in equatorial orbit will study ozone,rainfall, and oceanic biology. Data from these satellites, which will include detailedmeasurements and information about climate and weather, land, crops, oceantemperatures and currents, will be fed to ground-based computers for analysis byscientists. These data are expected to provide a more detailed and accurate picture ofthe evolving climate and ecosphere than is now possible with the fragmentarymeasurements from existing satellites and ground stations.