Hale Bradt is Professor Emeritus of Physics at the Massachusetts Institute of Technology. During his forty years on the faculty, he carried out research in cosmic ray physics and X-ray astronomy and taught courses in physics and astrophysics. Bradt founded the MIT sounding rocket program in x-ray astronomy, and was a senior or principal investigator on three missions for x-ray astronomy. He was awarded the NASA Exceptional Science Medal for his contributions to HEAO-1 (High Energy Astronomical Observatory), the 1990 Buechner Teaching Prize of the MIT Physics Department, and shared the 1999 Bruno Rossi prize of the American Astronomical Society for his contributions to the RXTE (Rossi X-ray Timing Explorer) program. His previous book, Astronomy Methods: A Physical Approach to Astronomical Observations, was published by Cambridge University Press in 2004.