Qualifying a watch to fly to the Moon

Almost everything on the Apollo lunar missions was custom made. Each spacecraft was flown once, every astronaut had his spacesuit custom made, and even diets were customized for each man. But the watches astronauts wore on the Moon weren't custom at all. They weren't even specially made by NASA. All the Apollo astronauts wore Omega Speedmaster timepieces on their lunar missions, turning the off-the-shelf watch into one of the most recognizable commercially available brands of the space age.

The Speedmaster’s Quiet Debut

The Omega Speedmaster was a serious watch well before NASA started strapping it to astronauts’ wrists. Extremely reliable because of its manual-wind design, its key feature was its chronograph: 30 minute and 12 hour counters located at 3 o’clock and 6 o’clock positions on the watch’s face, plus an additional sub dial at the 9 o‘clock spot. In the early 1960s, it was marketed primarily as a sports and racing watch. Then the astronauts found it.

In the fall of 1962, Wally Schirra was among a group of astronauts who went shopping for watches in Houston. Looking for something to wear on their Mercury flights, they came across the Omega Speedmaster, and each of the astronauts bought one. Schirra’s own Speedmaster was strapped around his wrist when he launched into orbit aboard Mercury 8 on October 3 of that year. On that, flight both man and watch performed a textbook mission. Schirra’s Speedmaster survived the vibrations of launch, the pure oxygen environment inside the Mercury capsule, and the shock of an ocean landing.

It wasn't until two years later that the astronauts approached NASA management with a request for watches to wear in space: a NASA-issued, spaceflight-qualified watch. With the Gemini and Apollo programs on the horizon, missions were about to get far more complex than the simple Mercury orbital flights. For the astronauts, having a handy way to keep track of mission events while transferring between vehicles or leaving the safety of their spacecraft was paramount. NASA agreed that a timepiece separate from the spacecraft’s own computer would be valuable on these missions.

Ed White, with an Omega Speedmaster on his left wrist, during NASA's first EVA in 1965.


On September 29, 1964, NASA ordered a sample of watches from Rolex, Longines, and Omega (the Speedmaster cost just $82.50 at the time) to be put through a specially designed series of tests. Knowing that spaceflight would expose the hardware to punishing conditions, the agency sought to replicate the trials of spaceflight as closely as possible in qualifying each of these timepieces.

A watch strapped to an astronaut’s wrist outside the carefully controlled atmosphere of his spacecraft would be exposed to significant temperature variations. Just by twisting his arm from sunlight to shadow, an astronaut could subject his watch to a temperature change of up to 200 degrees Fahrenheit. On the Moon’s surface, it gets even worse, with difference between light and shadow varying from -256 to 248 degrees Fahrenheit. NASA needed to know what this fluctuation would do to a watch’s delicate mechanics; there was no sense sending the astronauts with a watch that would fail the moment they stepped outside. There were other concerns, too, like how the watch would withstand the pure oxygen environment in the crew cabin without oxidizing.

The first round of testing for the watch samples involved accuracy of timekeeping, as there was little point in putting a watch through rigorous testing if it couldn't keep time to begin with. The watches were all wound before each test, and accuracy and time checks were made at regular intervals with the samples matched against a master timekeeper. Throughout this preselection process, technicians also looked at the watches physically. Any damage, be it to the casing, mechanics, or outer features like buttons, would be enough to pull the watch from contention.

Of the six watched NASA put through this preselection process, only three survived. These went on to the second set of 11 strenuous tests, possibly the most demanding tests in the history of watch making.

The Speedmaster during testing.

Flight Qualification Testing

First, there were a series of temperature tests. On the high end of the scale, each watch spent 48 hours in a sealed chamber heated to 160 degrees Fahrenheit before the dial was turned up to 200 degrees. The environment was designed to mimic spaceflight conditions; the heat chamber was pressurized to 0.35 atmospheres and kept with a relative humidity below 15 percent. On the other end of the scale was a cold test, where watches sat at zero degrees Fahrenheit for four hours.

Another series of tests mimicked the vacuum of space. Watches sat in a near vacuum (a chamber pressured to about 0.0000001 atmospheres) while the temperature was cycled between highs and lows: 45 minutes at 160 degrees Fahrenheit, then 45 minutes at 0 degrees Fahrenheit. This cycle was repeated 15 times for a single test. A similar test in the near-vacuum chamber was designed to test whether the watches could withstand decompression. And on the other end of the pressure spectrum was a high pressure environment test. The samples were left in a chamber pressurized to 1.6 atmospheres for an hour.

Humidity is an inescapable problem in spaceflight, as astronauts exhale moisture with every breath. The humidity test saw each watch spend 240 hours in a chamber heated between 68°F and 160°F while the relative humidity remained constant at 95 percent. To closely replicate human exhalation, the steam that made the chamber humid was kept at a neutral pH balance between 6.5 and 7.5. A similar environmental test was the oxygen test, a gas that both keeps men alive in space and also corrodes metal. As part of its flight qualification test, each watch was put in a 100% oxygen environment pressurized to 5.5 psi (or about 0.35 atmospheres) at a temperature of 160 degrees Fahrenheit. Over the course of this 48-hour test, technicians were looking for anything irregular, from poor performance to visible burning, the appearance of toxic or obnoxious gases or odors, or any deterioration of the seals and lubricants that kept the watch mechanisms running smoothly.

To test whether the sample watches could withstand the normal jostling of a mission, each was subjected to six separate shocks pulling 40 Gs (40 times the force of gravity) lasting 11 milliseconds each, and each coming from a different direction. Test watches were also accelerated from 1 to 7.25 Gs within three seconds, mimicking the acceleration of a launch. Just like spacecraft, the watches were also subjected to vibration tests to make sure they would stay together as a rocket gathered speed and momentum leaving the Earth. They were shaken in all three axes in 30 minute cycles. They were then exposed to a frequency escalating from 5 to 2,000 cycles per second and back again in 15 minutes, a test that mimicked an acceleration of almost 9 Gs. There was also acoustic testing, also related to the watch surviving a ride on a rocket. Each sample was exposed to 130 decibels over a frequency range from 40 to 10,000 Hz for half an hour.

A Speedmaster Professional and its flight qualification report card.

The Omega Speedmaster Professional

At the end of this test period, the winner was clear: only the Omega Speedmaster came through unscathed. Other samples were pulled from the testing with broken faces, warped mechanisms, and general degradation. NASA made an official announcement on March 1, 1965. In a press release, the agency named the Speedmaster as the only watch fit for spaceflight. Understood in NASA’s announcement was that the Omega Speedmaster was the agency’s officially endorsed watch. Citing the astronauts’ unanimous preference for the Speedmaster and its superior performance, it would be the watch that would accompany the first men to land on the Moon.

The newly-cleared timepieces were calibrated and issued to the Gemini 3 astronauts, and on March 21, Gus Grissom and John Young wore the first NASA-approved watches on their orbital mission.

The Speedmaster’s Legacy

Not until pictures of the Speedmaster attached to Ed White’s spacesuited wrist during America’s first spacewalk (with a specially designed long velcro strap) did Omega know for sure that NASA had made its watch the official watch of the space program. To reflect the change in status, Omega changed the name of its NASA-approved watch to the Omega Speedmaster Professional.

The Speedmaster Professional proved its worth on many occasions. As Buzz Aldrin wrote in his memoirs, Neil Armstrong left his own watch in the Lunar Module Eagle during their moon walk to replace the malfunctioning computer timer. On Apollo 13, with both the Lunar Module and Command Module shut down, the crew used their Speedmasters to time the mid-course correction burns that ensured they got home safely.

Today, the Speedmaster remains a favourite watch among space fans and collectors. Though most of the flown items are in museums, there have been a plethora of reissued Speedmasters commemorating Schirra’s first spaceflight, the Apollo 11 Moon landing, the Apollo Soyuz Test Project, and the Apollo program generally. Of course, the Speedmaster is still marketed, though the price has gone up a little bit from the $82.50 NASA spent on it’s original test article: a brand new one will set you back about $3,000.

Further Reading: Omega Press Kit; Omega Speedmaster Professional Chronographs (NASA); Omega's Presidential Campaign; Omega Press Kit

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