Earth Observation (EO) with satellites has become well established in the last decades, among others the US Landsat series and European ERS-1, ERS-2 and ENVISAT. However, Earth Observation applications have been slow to develop and become commercially viable. However, small low-cost satellites are changing the equation. With a cost one-tenth of the original satellites, and a much more rapid build-launch cycle, these are bringing Earth Observation into a fully operational phase.
In Europe, the Global Monitoring for Environment and Security (GMES) program is steadily working towards defining and implementing services, based upon EO data, to meet the policy directives of the EU. To do this requires a full definition of the spatial, spectral and temporal requirements for a myriad of end-users, and a series of Sentinel satellites is planned to meet these needs. In the meantime, data requirements will be met from a number of existing satellite providers. In 2007 the first Fast Track service is being launched, providing land cover monitoring of 37 states in and around the EC.