This project will study the electronic spectra of known and postulated carbon chains and rings using a combination of spectroscopic techniques, including Fourier transform microwave spectroscopy, laser-induced fluorescence, resonance-enhanced multiphoton ionization, and cavity ringdown spectroscopy. The purpose of the research is to conduct experiments in the laboratory that will provide a crucial test to the theory that long carbon chains and other large molecules are the carriers of the diffuse interstellar bands. At the same time the results could provide insight into the fundmentals of carbon chemistry, in particular, the formation of C60 and other fullerenes from simple precursors. Exemplifying the strong interdisciplinary nature of this work, this project is co-sponsored by the Divisions of Physics, Chemistry, and Astronomy and the Office of Multidisciplinary Activities in the MPS Directorate.