Charles Sheffield (25 June 1935 – 2 November 2002), was an English-born mathematician, physicist, and science-fiction writer who served as a President of the Science Fiction and Fantasy Writers of America and of the American Astronautical Society.American Astronautical Society "History of AAS: 1974 to Present". Retrieved 4 June 2009.
Charles Sheffield (25 June 1935 – 2 November 2002) was an English-born mathematician physicist and science-fiction writer who served as a President of the Science Fiction and Fantasy Writers of America and of the American Astronautical SocietyAmerican Astronautical Society "History of AAS 1974 to Present" Retrieved 4 June 2009