Abstract The paper describes the DLR small satellite mission “BIRD” (Bi-spectral Infrared Detection). The BIRD mission is dedicated to hot spot detection and investigation from space by means of new developed infrared array sensors. They are suitable for Earth remote sensing with small satellites. A dedicated two-channel cooled infrared sensor system is developed for hot spot detection and investigation from space. It is combined with a two-channel VIS/NIR sensor system for special questions of the remote sensing of vegetation. The sensor system and data processing algorithms are tested by airborne experiments. Results of the airborne experiments are pointed out in the paper. A speciality of this mission consists in the constraint to implement this payload on a micro satellite suitable for a piggyback launch. So the launch is not a main cost driver as for other small satellite missions with dedicated launchers. The mass of the complete satellite including payload and launch adapter has to be less than 100kg. To meet the particular requirements of the payload on the spacecraft bus a lot of new developments on component level are done. The paper describes the 3-axis stabilized satellite, the basic spacecraft modes, the mission architecture and the model philosophy within strict design-to-cost constraints. The BIRD mission is now in the Phase C D and will be ready for launch in the summer of the year 2000.