The prime interest of our research is to experimentally study the dynamics of chemical reactions in extreme environments like combustion systems, rocket engines, chemical vapor deposition processes, and extraterrestrial environments (interstellar medium, solar system, comets, astrobiological habitats). In our crossed molecular beams machine, we use photolytic, pyrolytic, and laser ablation techniques to generate supersonic beams of neutral atoms (carbon, boron, silicon), polyatomic radicals (cyano, ethynyl, phenyl, propargyl, vinyl) and clusters (dicarbon, tricarbon). The chemical reactions are initiated under single collision conditions by crossing such beams with a second supersonic beam containing radicals or closed shell species. By recording angular resolved time of flight (TOF) spectra, we can obtain information on the reaction products, intermediates involved, on branching ratios for competing reaction channels, on the energetics of the reaction(s), and the underlying reaction mechanisms. This research helps to understand elementary reaction mechanisms with applications to combustion chemistry, rocket propulsion systems, extraterrestrial chemistry, and chemistry in our Solar System such as in Titan's atmosphere. These projects are supported by (in alphabetic order) the Air Force Office of Scientific Research (AFOSR), the Department of Energy (DOE-BES), and by the National Science Foundation (NSF-CHE; NSF-CRC). The following research areas are currently under investigation in our group: