CloudSat was launched in April 2006. Since that time more than 300 peer-reviewed papers have been published using CloudSat data, more than a trillion data files have been distributed and the data are being used directly in aviation. The recent problems of the host spacecraft reminds us that the mission is nearing its end of life. This talk will highlight major scientific advances that have occurred. CloudSat has shown unequivocally how observing systems can be constructed as a combination of smaller mission through the use of formation flying. The ability of the radar itself has offered unique insights. The ability to profile clouds has allowed us now for the first time to characterize the structure of weather systems and planetary cloudiness. We are now beginning to gain a deeper understanding of weather systems and testing how well we really represent the way water cycles through them. Profiling the structure of clouds provides a more definitive way of determine the effects of clouds on the radiation balance of the atmosphere, deeper insights on convection and severe weather. As part of the A-Train, the combination of radar and other observations has been a revelation in the insights it offers on processes including precipitation formation. These observations have also indicated significant limitations of existing cloud climatologies clearly suggesting radar observations need to be considered as the foundation for any future satellite system designed to study clouds.