Charles Sheffield (1935-2002) was a mathematician and theoretical physicist by training. His doctoral work was on Einstein's Special Theory of Relativity. Dr. Sheffield worked as chief scientist for the Earth Satellite Corporation, a Washington, D.C.-based firm that specializes in the analysis of data gathered from space.
The author of many science fiction novels, including Cold as Ice and The Ganymede Club from Tor, Sheffield lived in Silver Spring, Maryland, with his wife, author Nancy Kress.