Full quantum control of molecules has been an outstanding goal for decades. Cooling molecules provides a most promising answer to address this challenge. With recent progress in experimental quantum physics, such cooling is finally within reach. The aim of this project is to demonstrate the novel technique of molecular laser cooling for a gas of barium monofluoride molecules. Realizing a cold gas of these dipolar molecules will pave the way for a large number of novel and interdisciplinary applications ranging from few- and many-body physics to cold chemistry and tests of fundamental symmetries. The combination of this unique research project with the excellent environment for training, networking and research at the University of Stuttgart will ideally prepare the applicant, Dr. Tim Langen, for a future career as an independent research group leader.