Satellite data is an indispensable tool for quickly assessment of the situation in cases of natural or environmental disasters and for guiding emergency teams on ground. DLR's 'Center for Satellite Based Crisis Information' (Zentrum für satellitengestützte Kriseninformation; ZKI) and many other international organizations have been using the German radar satellite TerraSAR-X for three years to rapidly obtain reliable data in all weather conditions for such crisis situations. Now, our new satellite, TanDEM-X, has also provided assistance for the first time in a crisis – gathering information on the flood catastrophe in Pakistan. We were able to help not only with radar images but we also used TanDEM-X for interferometry in formation with TerraSAR-X for the first time. This has provided a more reliable technique to map floods instantaneously and more accurately, in one pass and without the need for archived data.