Research Scientist, Space Science Division, NASA-Ames Research Center (1980-present)
National Research Council Associate, NASA-Ames (1979-1980)
Research Scientist, University of California at Berkeley (1975-1979)
• Principal Investigator of the Center for Star Formation Studies 1985-present
• Principal Investigator and Co-Investigator on numerous theoretical grants concerning the evolution of the interstellar medium, star formation, interstellar and protoplanetary dust, and the evolution of protostellar disks.
• Significant involvement in a number of space missions which studied or are going to study the interstellar medium and star formation, including KAO. SWAS, ISO, SIRTF, and SOFIA. The most relevant is Co-Investigator on the SIRTF Legacy Program "Formation and Evolution of Planetary Systems"