Missile Guidance Computer

 
This Borroughs computer was used to steer early Thor and Redstone missiles as they left the pad and flew downrange. No computer was small enough to put into the missiles in the late 1950s and early 1960s so tracking data had to be fed into a room sized computer like this in real time and guidance commands sent by radio to the missile as it climbed out. Today your hand calculators have more computing power than this behemouth and by the late 1960s, roughly the capability of this computer was able to fit into the Apollo spacecraft. This image was taken with the kit lens on my 20D at 18mm focal length with an exposure of 1/25 seconds at f/5.6, ISO 1600.