K. Eric Drexler did much to develop and publicise the concept of nanotechnology
in the early 80's. It came to prominance when he published his book "Engines of Creation
" (1986). He worked for a very long time at MIT
and even had Marvin Minsky
write the foreward for Engines.
He founded the Foresight Institute in 1986 to encourage and foster awareness and knowledge of Nanotechnology and related disciplines (Hypertext is another idea they have been involved in since long before the world wide web).
He has also had a great deal to do with space exploration and develoment having been strongly involved with the L5 society and the National Space Society until recently.