The PI's (S. Ruden) principal research interests lie in the physics of the formation of stars and planets, particularly, in the formation of the solar system. During the five-year tenure of his PYI award, the PI will concentrate on the theoretical dynamics and evolution of accretion disks around contracting proto-stars. He will also investigate the dynamics and chemistry of powerful winds that flow from these young stars and which are thought to modify the protostellar environment considerably. The overall goal of this program is to increase the understanding of the physical conditions and evolutionary timesales required for the formation of planets around sun-like stars.