He wrote the "2001", "2010", "2061" & "3001" Odyssey books
.... as it is 
later shown in 2061 and 3001 manned spacecraft that attempt to land have been 
... he then wrote the rest of the novel using this method and 2010 is therefore ... 
sequel to 2001: A Space Odyssey, so this book is not a linear sequel to 2010.