9402461 Thaddeus Drs. Thaddeus and Gottlieb, at Harvard University, will continue a program of laboratory millimeter-wave spectroscopy of reactive molecules of astrophysical interest. The emphasis of the investigation will be on detection of key reactive species believed by astrochemists to be involved in molecular formation in space. Two complementary methods of reactive molecule production -- gas discharge and H abstraction -- will be used. Several small three-membered carbene rings are excellent candidates for detection, and specific five-membered carbene rings will be sought.