His novel The Web Between the Worlds, featuring the construction of a space elevator was published almost simultanenously with Arthur C. Clarke's novel about that very same subject, The Fountains of Paradise, a coincidence that amused both of them.
For some years he was the chief scientist of Earth Satellite Corp., a company analysing satellite data. Besides many technical papers, a spin off of this was two notable and popular non-fiction books, Earthwatch and Man on Earth; collections of false colour and enhanced images of Earth from space.
He won the Nebula and Hugo awards for his novelette "Georgia on My Mind"; he received the 1992 John W. Campbell Memorial Award for "Brother to Dragons."
He had been writing a column for his publisher's (Baen Books) Web site: the last column he wrote there was about the discovery of the brain tumour that led to his death.
Some autobiographical notes (external link): http://www.sff.net/people/sheffield/bio.htm
wikipedia.org dumped 2003-03-17 with terodump