Satellites are our only way to get global and frequent data about the state of the atmosphere. They are the most important component of the Global Observing System since late 1970s and they provide 99% of observations needed for numerical weather prediction. Decades long time series of satellite observations areindispensible tools for climate research. To use these data, one has to be able to model the transfer of radiation through the atmosphere very accurately. Besides our work on radiative transfer, we also play a leading role in developing the next generation of weather and climate satellites such as ICI and FORUM. We work on the potential and real impact of satellite observations such as the first wind profiles by ESA’s Aeolus satellite.