The Speedmaster, and the eleven tests NASA set

September 28, 2026|Toni

Distant view of the Gemini-Titan 3 rocket lifting off from Cape Kennedy, 23 March 1965

Cape Canaveral, 3 October 1962. Wally Schirra lifts off in a Mercury capsule called Sigma 7. On his wrist is an Omega Speedmaster, and it belongs to him, not to NASA. Nobody tested it for spaceflight. Nobody chose it. According to Omega, it is the first of its watches to leave the atmosphere.

Mercury-Atlas 8 rocket lifting off from Cape Canaveral with the Sigma 7 capsule, 3 October 1962 — Mercury-Atlas 8 leaves Cape Canaveral with Wally Schirra aboard Sigma 7, 3 October 1962. Image: NASA (S62-07872).

Two years later NASA stopped leaving the question to the astronauts. In 1964 it asked watchmakers for chronographs, put the ones that arrived through eleven tests written for spacecraft hardware, and on 1 March 1965 declared one watch fit for manned flight: the Speedmaster, reference ST 105.003. It was the same model sold over the counter. How it got there is a better story than the one usually told.

Maker: Omega, Switzerland
Years: Speedmaster introduced 1957; flight-qualified by NASA on 1 March 1965
Person: James H. Ragan, the NASA engineer who ran the tests
Reference tested: ST 105.003, with the calibre 321 chronograph movement
What made it different: the only chronograph submitted that came through all eleven tests

Why NASA wanted a wristwatch at all

A spacecraft has its own timers. The question was what an astronaut had if they failed, and what he had outside. Gemini was going to put a man on the end of a tether, and nothing on the instrument panel goes with him.

So NASA wanted its astronauts to wear a mechanical wristwatch as a backup, inside the vehicle and out. The requirement, as Swatch Group set it out for the sixtieth anniversary of the qualification, was an accuracy of five seconds a day, ideally two. The watch also had to survive everything the spacecraft survived: launch, vacuum, heat, cold, pure oxygen and noise.

A watch that only worked because its movement ran on springs had one quiet advantage here. It needed no power from the spacecraft. It is the same argument that keeps mechanical cameras working long after their batteries have gone.

An engineer hired for cameras

James Ragan joined NASA in 1964, early in the Gemini programme. He had been taken on to buy and test photographic hardware. Then the watch question landed on his desk. He later described the moment to Revolution magazine: "They called me in and said, 'We need a watch.' And I said, 'I thought you hired me for photographic hardware.'"

The request itself went out as a letter from Donald K. "Deke" Slayton, NASA's Assistant Director of Flight Crew Operations. Ragan drew up the list of recipients, about ten brands by his account, and said any watchmaker that wanted a copy could have one. Four companies sent watches. Omega's own history confirms it was one of the four.

One entry fell at the first hurdle, before any testing, because it did not meet the basic specification, according to WatchTime. That left three chronographs on Ragan's bench. Swatch Group names the two competitors as a Longines-Wittnauer 235T and a watch it identifies only as reference 6238, which Revolution's account of the Ragan interview names as a Rolex. The third was the Speedmaster ST 105.003.

Astronaut in a pressure suit inside Chamber B, a thermal vacuum chamber at the Manned Spacecraft Center in Houston, May 1969 — Thermal-vacuum training in Chamber B at the Manned Spacecraft Center, Houston, May 1969. The watches that failed in NASA's tests failed in heat and vacuum. Image: NASA (S69-33797).

Eleven tests written for a spacecraft

The tests were not designed for watches. They were NASA's qualification tests for flight hardware, the things bolted inside a capsule. As WatchTime lists them, each watch went through:

High temperature: 48 hours at 70°C, then 30 minutes at 93°C in partial vacuum
Low temperature: 4 hours at −18°C
Temperature and pressure: repeated heating in a vacuum chamber, then cooling to −18°C
Humidity: ten 24-hour cycles at 95% humidity between 25°C and 70°C
Oxygen atmosphere: 48 hours in pure oxygen at 70°C
Shock: six shocks of 40 G, in six directions
Acceleration: building to 7.25 G, then 16 G for 30 seconds, on three axes
Low pressure: one millionth of an atmosphere at 70°C for 90 minutes
High pressure: 1.6 atmospheres for an hour
Vibration: 5 to 2,000 Hz for 30 minutes, at 8.8 G on three axes
Noise: 130 decibels between 40 and 10,000 Hz for 30 minutes

Ragan did not expect much to survive. "Even I was surprised that I could get any watches through those tests," he told WatchTime. "The environments were really made for pieces of hardware that you mount on vehicles."

What failed, and how

Two of the three did not get far. Both broke down in the heat-and-vacuum stage. On one, the long chronograph seconds hand warped until it fouled the other hands. On the other, the crystal deformed and came away from the case. Accounts differ on which watch suffered which fault.

The Speedmaster kept running through all eleven.

Ragan then did something that tells you how he thought. He gave the astronauts all three watches to try and did not tell them the test results. According to his own account, every one of them preferred the Omega. That made his recommendation an easy one to carry upstairs: the watch had passed, and the crews wanted it. The qualification is dated 1 March 1965.

A watch from a shop window

Here is the part that tends to get lost. NASA did not commission a watch. It did not ask Omega to modify one. The page that NASA's own Apollo Lunar Surface Journal keeps on the Speedmaster is plain about it: the watch "was not manufactured for use specifically by NASA or in space." It had been on sale in shops in Houston and across the United States since 1957, first as the Speedmaster and, from about 1966, as the Speedmaster Professional.

The same page adds a detail that is hard to believe and, as it says itself, unconfirmed. There are reports that Omega only discovered NASA was using the watch after Ed White wore it outside Gemini 4.

Astronaut Edward White floating outside the Gemini 4 spacecraft during the first American spacewalk, 3 June 1965 — Edward White outside Gemini 4 on 3 June 1965, the first American spacewalk. He stayed out for about 21 minutes. Image: NASA (S65-34635).

The Corrigan's story, and what the record says

That idea of NASA as an anonymous customer has a well-known version. It says NASA staff quietly bought a handful of chronographs from Corrigan's, a jeweller in Houston, and tested them without the makers knowing. It is repeated in watch histories to this day.

The record points somewhere else. Ragan's account describes a formal letter over Slayton's name, a list of brands, and companies sending watches in reply. Omega's own history says it submitted watches after NASA requested quotes. Neither mentions a jeweller.

There is a grain of truth that may explain how the legend grew. The Apollo Lunar Surface Journal notes that from around 1962 NASA did buy commercially available watches for evaluation. Buying off the shelf was real. A named shop and a secret purchase, for the 1964 tests, is not something any NASA source consulted for this article supports. Treat it as a story.

Three weeks, then outside

The qualified watch flew almost at once. WatchTime puts its space debut on Gemini 3, launched on 23 March 1965 with Gus Grissom and John Young aboard. On 3 June 1965 Ed White opened his hatch on Gemini 4 and floated out on a tether for the first American spacewalk, with a Speedmaster on his wrist.

By 1969 the qualified reference had moved on. Swatch Group identifies the ST 105.012 as the first watch worn on the Moon. Even that moment has a twist. According to the Apollo Lunar Surface Journal, Neil Armstrong left his Speedmaster inside the lunar module, as a replacement for an in-cabin timer that had failed. The watch on the surface was Buzz Aldrin's. It was lost in transit around 1971, on its way to the Smithsonian, and nobody knows where it is.

The Smithsonian's National Air and Space Museum now holds 63 Speedmasters and Speedmaster Professionals, most of them acquired in the mid-1970s. Armstrong's is one of those on display.

What a collector looks at now

The nickname came later. What NASA qualified was a reference number, and that is still where a collector starts. The ST 105.003 is the watch Ragan tested. The ST 105.012 is the one that went to the Moon. Both carry the calibre 321, which Omega used in the Speedmaster from 1957 until 1968, and which it considered important enough to put back into production more than fifty years later.

So the first two questions about any Speedmaster Professional ("Moonwatch") from the 1960s are the reference inside the caseback and the calibre behind it. The name changed too: from about 1966 the watch was sold as the Speedmaster Professional. Everything else, the hands, the bezel, the crystal, is about whether the watch has stayed what it was.

The watch Schirra chose

It is worth going back to Sigma 7. Before there was a letter, a list of ten brands or a vacuum chamber, one astronaut had already picked the same watch, for reasons of his own. Three years and eleven tests later, NASA agreed with him.

You can see what is in the chronograph collection or browse all watches in the shop.