This Omega Speedmaster Professional model ST 105.012 is the model watch with a 321 Calibre movement worn by both Neil Armstrong and Buzz Aldrin during the Apollo 11, the first lunar landing mission, in July 1969.
Although Apollo 11 commander Neil Armstrong was first to set foot on the moon, he left his 105.012 Speedmaster inside the Lunar Module as a backup because the LM's electronic timer had malfunctioned. Lunar Module Pilot Buzz Aldrin elected to wear his and so his “Speedy” became the first watch to be worn on the moon.
I’m thrilled to own an example of the world’s most famous chronograph.
According to the Apollo Lunar Surface Journal, NASA supplied each of the Apollo astronauts with a standard issue Omega Speedmaster Professional manual-wind wristwatch together with Velcro strap. Unlike almost all other Apollo equipment, the watch was not manufactured for use specifically by NASA or in space but had been the same model that had been on sale in retail outlets.
Aside from its primary and obvious function, the Omega Speedmaster Professional also incorporated a chronograph (stopwatch) via the large third hand on the watch dial. The three interior dials on the face provided respectively a) a second-hand, ancillary to the conventional time function b) a minute elapsed counter for the chronograph and c) an hour elapsed counter, again related to the chronograph function. The outside of the dial included a fixed bezel incremented to act as a Tachymeter (to measure miles per hour) in conjunction with the stopwatch function, hence the title "Speedmaster".
The timepiece was intended to be worn for intra and extra vehicular activities including the moonwalks on all the missions. Inside a pressurized environment the watch was worn conventionally but during EVA (extra vehicular activity) the astronauts wore the watch on the outside of their pressure suits, the long Velcro strap was designed to accommodate this change in 'wrist' dimension.
My example has a slightly worn bezel. The face has some interesting toning which changes the dial from black to brownish. It did not come with an original band, so I put a modern Omega brown band on it and it looks terrific.