In celebrating the 60th Anniversary of the Omega Speedmaster, we take a look through the loupe at the historical and horological significance of this iconic timepiece.
The crew of Apollo 11, from left to right: commander Neil Armstrong, command module pilot Michael Collins, lunar module pilot 'Buzz' Aldrin. 
The CK2915, notice the 'broad arrow' hands, steel bezel, and 'straight lug' case. The First 'Speedy' CK2915 (1957 - 1959)
While the Speedmaster is known to most as the “Moon Watch”, its life began completely unintended for space exploration. Omega introduced the first ‘Speedy’ in 1957 (reference CK2915) as a racing and sports chronograph, which also complemented Omega’s position as the official time keeper of the Olympic Games, and completed their range of professional tool watches in addition to the CK2913 Seamaster (dive watch) and CK2914 Railmaster (aviation watch).
From a technical point, Omega used the Manual wound, colum-wheel chronograph caliber 321, which was developed in collaboration with Lemania, and featured an antimagnetic cover and shock-protection. It was also the first watch to feature a tachymeter scale for calculating speed on its steel bezel, rather than on the dial. The CK2915 also had very distinct hands known as the ‘Broad Arrow.’ With only two years in production (1957-1959), the next step in the evolution of the Speedmaster took away some of these subtle details, making the CK2915 (in all original condition) a grail watch for Omega collectors. On the market today, an all original CK2915 could fetch anywhere from $40,000 to over $100,000 USD as it did at Christie’s Omega Speedmaster 50 auction back in 2015.
The CK2998 (1959 - 1962)
Introduced in 1959, the CK2998 represents the second iteration of the Speedmaster. And while it was technically the same watch, it came with some improvements and aesthetic changes. The steel bezel was replaced by a black anodized aluminum insert to increase the legibility of the tachymeter scale. The case size was also made slightly bigger, from 39mm to 40mm, to accommodate the new bezel. O-ring gaskets around the pushers to improve water-resistance were added, and the hands were changed from ‘broad arrow’ hands to ‘Alpha’ hands. The CK2998 was also the first ‘Speedy’ that went to space when astronauts Wally Schirra and Gordon Cooper wore their personal CK2998s during the Mercury 8 and 9 missions in 1962.
The CK2998, notice the change in hands to the 'alpha' hands, the black anodized aluminum insert, and 'straight lug' case.
A NASA inspected and certified Speedmaster ref. ST 105.012 from 1963. The Speedmaster started to get the attention from NASA after astronaut Wally and Gordon’s Mercury missions. With some persuading from Wally, NASA began to recognize the dangers of astronauts using ‘personal’ tools on missions, and the need for an officially certified watch that could operate in extreme conditions. This task was taken up by a young NASA engineer James H. Ragan, who procured watches from four brands through their distributors in the US, including Longines-Wittnauer, Rolex, Hamilton, and Omega (the companies were actually not aware of what was going on as NASA did not contact them directly). Of the four brands, Hamilton submitted a pocket-watch chronograph that was immediately disqualified as it did not meet the wrist-watch specification. The watches from the three brands underwent a series of tests known as the “Qualification Test Procedure” which included the following:
The 11 different tests that NASA performed on the Speedmaster. 
Some of the mission-worn Speedmasters, including Wally Schirra's personal CK2998, a ST 145.012, and a ST 105.003. 
The crew of Apollo 13 receiving a hero's welcome after safely returning to Earth. The Speedmaster was recognized as an important tool in getting them back home. 
The ST 105.003 aka 'Ed White,' notice the 'baton' hands, and signature diamond tip and water-drop shaped counterweight on the chronograph seconds hand. The ST 105.002 / ST 105.003, (1963 – 1965)
Replacing the CK2998, the third iteration of the Speedmaster came in 1963 with the ST 105.002 and ST 105.003. Again, the watches were technically very similar to their predecessor, but saw another aesthetic change from ‘Alpha’ hands to the current style ‘Baton’ hands. The chronograph seconds hand was also changed to the more familiar diamond shaped tip with water-drop shaped counter weight. For this particular reference, various bezel inserts such as the pulsometer (to calculate heart beats), and telemeter (to calculate distance) were available. While the CK2998 had been the first ‘Speedy’ to go to space, it was the the ST 105.003 that underwent official testing by NASA (as mentioned earlier). In 1965, the ST 105.003 became the first watch worn in the vacuum of Space when astronaut Ed White performed the first American spacewalk while wearing his newly qualified ‘Speedy.’ Consequently, the ST 105.003 is also known as the ‘Ed White.’
Astronaut Ed White performing the first American spacewalk. On his wrist wrapped around his space suit, the ST 105.003. 
Astronaut Ed White preparing for launch. Clearly visible on his wrist is the ST 105.003.The ST 105.012 “The Moon Watch” (1963 – 1966) and ST 145.012 (1967 - 1968)
Introduced around the same time as the ST 105.002 and 105.003 in 1963, the reference ST 105.012 is perhaps the most significant reference in the Speedmaster lineage (excluding the CK2915) for two reasons. First, it is the ‘Speedy’ worn by Neil and Buzz on the moon, and so it is technically THE watch that went to the Moon. Second, it represents a transitional point between the old and new Speedmasters with one defining characteristic: the new and improved case. Prior to the ST 105.012, all Speedmasters had what is called a ‘straight lug’ case that exposed the crown and pushers, increasing the chances of damage from contact with other objects. In addressing this issue, Omega created an asymmetrical design of the sides with faceted lugs called ‘Lyre lugs’ that also acted as protection for the crown and pushers. The case size was also increased from 40mm to 42mm, and it is the distinct case shape that has come to define the Speedmaster ever since. To note this major change, Omega also included the line ‘PROFESSIONAL’ to the dial, and the watch became formally known as the Omega Speedmaster Professional. In 1967, Omega re-referenced the ST 105.012 to ST 145.012, which was the last reference to use the coveted caliber 321. It is important to note that Omega supplied NASA with the ST 105.012 and the ST 145.012 during the Apollo missions.
The ST 105.012 'Moon Watch,' notice the new case style with 'lyre lugs' and the 'Professional' line on the dial.
Astronaut Buzz Aldrin in the command module of Apollo 11. On his wrist, the ST 105.012. 
The ST 145.022, the last of the 'vintage' Speedmasters. Notice the printed Omega symbol on the dial as opposed to the applied Omega symbol used in all previous Speedmasters. The ST 145.022 The last of the “vintage” Speedmasters (1968 – 1978)
In 1968 came the next evolution of the Speedmaster with the ST 145.022. On the outside, it looked exactly the same as the ST 145.012 but had one significant difference: the movement. Omega decided to use the Newly developed..... manually wound, cam-operated chronograph caliber 861, as opposed to the column-wheel movement like the caliber 321. And while the merits of the caliber 861 over the caliber 321 should be left for another discussion, it is must be said that, for vintage Omega collectors, the Speedys with the caliber 321 are more sought after than those with the caliber 861. There was also a subtle change in the dial with the printed Omega symbol as opposed to the applied Omega symbol present in all previous Speedmasters. The ST 145.022 also represented the last of the “vintage” Speedmasters and every iteration thereafter saw slight improvements to the movement with the likes of the caliber 863 to the modern caliber 1861 and so on.
Omega Speedmaster Alaska II (Prototype) 1972.
Omega Speedmaster Alaska III 1978.
Omega Speedmaster Alaska IV (quartz LCD with cal. 1621) 1979.
Omega Speedmaster with 'racing dial' 1968.
Omega Speedmaster known as the 'Ultraman' 1968. It got its nickname after appearing in Japan's Sci-Fi TV show,
First Omega Speedmaster in 18k gold 1969. The first few watches in this series were presented to 19 astronauts on November 25th 1969 to celebrate the Apollo 11 moon landing.
Omega Speedmaster 'Speedymoon' 1985. A first in the Speedmaster series to include the moonphase complication.
Omega Speedmaster 'Speedmaster 57' 2015. Inspired by the first 'Speedy' launched in 1957.
Omega Speedmaster 'Speedy Tuesday' limited edition 2017.
Omega Speedmaster '60th Anniversary edition' 2017. A faithful reproduction of the first 'Speedy' in every respect.
Omega Speedmaster Alaska II (Prototype) 1972.
Omega Speedmaster Alaska III 1978.
Omega Speedmaster Alaska IV (quartz LCD with cal. 1621) 1979.
Omega Speedmaster with 'racing dial' 1968.
Omega Speedmaster known as the 'Ultraman' 1968. It got its nickname after appearing in Japan's Sci-Fi TV show,
First Omega Speedmaster in 18k gold 1969. The first few watches in this series were presented to 19 astronauts on November 25th 1969 to celebrate the Apollo 11 moon landing.
Omega Speedmaster 'Speedymoon' 1985. A first in the Speedmaster series to include the moonphase complication.
Omega Speedmaster 'Speedmaster 57' 2015. Inspired by the first 'Speedy' launched in 1957.
Omega Speedmaster 'Speedy Tuesday' limited edition 2017.
Omega Speedmaster '60th Anniversary edition' 2017. A faithful reproduction of the first 'Speedy' in every respect.