Omega Speedmaster Moonwatch: First Watch on the Moon

Short answer: The first watch worn on the Moon was an Omega Speedmaster Professional. In July 1969, Apollo 11 astronaut Buzz Aldrin walked on the lunar surface with his Speedmaster strapped over his spacesuit. Neil Armstrong's Speedmaster stayed inside the lunar module. The Speedmaster was the only chronograph to pass the punishing tests NASA completed in 1965.

The watch we now call the "Moonwatch" was not designed for space at all; it was built for racing. This story explains how the Speedmaster has changed since 1957, how NASA chose it, and exactly whose wrist it was on when it reached the Moon.

1957: Born as a racing chronograph

Omega introduced the Speedmaster in 1957 as reference CK 2915. Inside was the hand-wound Calibre 321 chronograph movement, developed from a Lemania design. The watch was named after its most distinctive feature: the tachymeter scale sat on the bezel rather than on the dial. With it you could time how long you took to cover a set distance and read off your average speed.

In other words, the Speedmaster started life as a chronograph for drivers and sportsmen. We cover the link between tachymeter chronographs and motor racing in our story on the Rolex Daytona.

When did it first go to space?

The Speedmaster went to space before NASA chose it, on the wrist of an astronaut who had bought his own. During the Mercury programme's Sigma 7 flight in 1962, Wally Schirra wore a Speedmaster CK 2998 he had purchased privately. It was not an official selection; the watch was simply his.

How did NASA choose the Speedmaster?

In 1964 NASA set out to find an official chronograph for its astronauts. On 21 September 1964, Director of Flight Crew Operations Deke Slayton wrote a memo calling for a durable, accurate chronograph, and NASA engineer James Ragan sent a request for quotation to about ten manufacturers.

Four brands responded: Rolex, Longines-Wittnauer, Hamilton and Omega. Hamilton was ruled out because it sent a pocket watch instead of a wristwatch (we tell Hamilton's own story in Where is Hamilton from?). The remaining three chronographs went through 11 tests, including:

• High temperature: 48 hours at 71 °C (160 °F), then 30 minutes at 93 °C (200 °F) in a partial vacuum
• Low temperature: 4 hours at −18 °C (0 °F)
• Humidity: 250 hours at 95% relative humidity
• Also: pure oxygen, shock, acceleration, low and high pressure, vibration and acoustic noise

The Rolex 6238 failed the humidity and high-temperature tests, and the Longines-Wittnauer 235T failed the high-temperature test. When testing ended in March 1965, only the Omega Speedmaster was left standing.

It soon faced its first big job. On 3 June 1965, Ed White made the first American spacewalk during Gemini 4, wearing a Speedmaster 105.003 over his suit.

1969: Whose wrist was it on?

The most common mistake about the Speedmaster is the claim that Armstrong and Aldrin both wore one on the Moon. That is not what happened.

The electronic timer in Apollo 11's lunar module, Eagle, was not working properly. So mission commander Neil Armstrong left his Speedmaster inside the lunar module as a backup timer. When Armstrong took the first step onto the Moon at 02:56 GMT on 21 July 1969, he had no watch on his wrist.

About 19 minutes later Buzz Aldrin climbed down the ladder with his Speedmaster strapped over the sleeve of his spacesuit. That made Aldrin's Speedmaster the first watch worn on the lunar surface.

NASA engineer James Ragan summed up the watch's role: if the astronauts lost contact with the ground or lost their digital timers, the only thing left to rely on was the Omega on their wrist. According to Omega, the Speedmaster was part of all six Moon landings.