I'm listening to a countdown. Not in the steamy Florida heat of Cape Canaveral. Or the desert winds of Baikonur in Kazakhstan. Instead this one is under way in a makeshift cabin under drizzly skies in a corner of Oxfordshire.
Some great inventions began in humble surroundings - think Bill Gates and Steve Jobs toiling in their garages - so I'm not being critical.
Twenty years ago David visited the secret lab at Los Alamos that created the nuclear bomb and he's been fascinated by science and scientists ever since. His reports on research have taken him as far afield as the Antarctic ice-sheet, the Amazon rainforest and the depths of the Gulf of Mexico.
Since joining the BBC back in 1983, David has covered Northern Ireland, defence, Europe and world affairs. He is the author of three books.
His favourite memories include reporting from East Berlin during the fall of the Wall and exploring the tunnels of the Large Hadron Collider on a bike.
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