The movement's design and development was begun in the 1940s by Albert Piguet and Jaques Reymond at Lemania. It was started as a project titled "27 CHRO C12" (27 cm diameter, chronograph, with extra 12-hour totaliser).
The very first Speedmaster model was released by Omega in 1957, and contained the 27 CHRO C12 movement (also called Lemania 2310, or Omega 321). Its unique case design is attributed to Claude Baillod. Omega made some external design changes to the watch in 1960 (black bezel, larger case 39 to 40 mm, dauphine hands replaced arrow-shaped hands).
When the step-by-step procedures of the Project Gemini space-walks were first mapped out, NASA realized that they did not have an approved wristwatch for space travel. The normal procedure of soliciting bids for the design, manufacture and testing of special “Space Proof” wristwatches was a time consuming process. To save time, NASA sent two systems engineers into downtown Houston “incognito” to purchase several reputable “off-the-shelf” chronographs to be tested for possible use in space. A manual-winding watch was preferred to an automatic watch, as it was assumed that zero-gravity conditions would render the self-winding mechanism ineffective.
Five different brands of chronographs were purchased and returned to NASA for testing. The Speedmaster passed NASA's numerous tests, which included exposure to extreme temperatures, vacuum, intense humidity, corrosion, shock, acceleration, pressure, vibration and noise , whereas the Rolex, Breitling, Bulova, Longines and TAG Heuer, notably, all failed.
The tests were completed on March 1st, 1965. At the completion of the tests, three of the chronographs from different manufactures were still running, but only the Speedmaster had passed without any of the serious discrepancies encountered with the others. The Omega Speedmaster was adopted by NASA as the “Officially Certified Wristwatch For All Manned Space Missions.” At this point, Omega was completely unaware of these activities.
The Omega Speedmaster Professional Chronograph was the first watch on the Moon worn on the wrists of Edwin 'Buzz' Aldrin. Unfortunately this particular historically notable watch is now considered missing. Astronaut Buzz Aldrin mentions in his book "Return to Earth" that when donating several items to the Smithsonian Institution, his Omega was one fo the few things that was stolen from his personal effects.