A blue plaque has been unveiled recognising an influential Cambridge engineer.
Francis Thomas Bacon, known as Tom Bacon, developed the first practical working hydrogen-oxygen fuel cell in the 1960s.
His work led US President Richard Nixon to say "without you Tom, we wouldn’t have gotten to the moon" in 1969.
The blue plaque was unveiled at Marshall of Cambridge, where the fuel cell was developed, and will be installed on Little Shelford High Street, where Tom once lived.