McMillan is in charge of the Spacewatch survey of the solar system for near-Earth asteroids, main-belt asteroids, Centaurs, comets, and Trans-Neptunian objects.
McMillan's career has included studies of variable stars, statistics of stellar populations, interstellar dust, interstellar magnetic fields, planetary atmospheres, Doppler shift spectroscopy of stars, astronomical instrumentation, and surveys of asteroids.
McMillan became the Principal Investigator of Spacewatch in mid-1997.
McMillan, R. Bressi, A. Descour, T. Gehrels, J. Larsen, J.
McMillan, R. "Spacewatch Discovery and Study of Accessible Asteroids." Abstract of paper presented at the Space Resources Utilization Roundtable at the Colorado School of Mines in Golden, CO: LPI Contrib.
McMillan, R. Bressi, A. Descour, T. Gehrels, A. Gleason, R. Jedicke, J. Montani, M. Perry, M. Read, J. Scotti, A. Tubbiolo.