[Launch Date: Estimated 2013]
The ESA Sentinels will be the first series of noperational satellites to meet the Earth lobservation needs of the European Union ESA Global Monitoring for Environment
... and Security (GMES) programme. The pair of Sentinel-3 satellites will provide global, frequent and near-realtime ocean, ice and land monitoring. It continues Envisat’s altimetry, the multispectral, medium-resolution visible and infrared ocean and land-surface observations of ERS, Envisat and Spot, and includes enhancements to meet the operational revisit requirements and to facilitate new products and evolution of services. The first launch is expected in 2011/2012.
Summary Source: http://www.esa.int/esapub/bulletin/bulletin131/bul131c_aguirre.pdf