Omega Speedmaster Moonwatch: The Watch That Went to the Moon

The journey to the Moon climaxing on July 20, 1969, when man set foot on non-terrestrial ground for the first time in the world history is one of my absolute favourite tales.

To me the Apollo 11 Mission was an engineering achievement of the greatest and a venture that required true superheroes to accomplish.

It was a sensational event and potentially an important step toward colonization of space.

Kennedy and the Space Race

When John F. Kennedy became President of the United States in January 1961 the technological war between United States and Soviet Union had already been heating up for years and there was a widespread perception with many Americans that the United States was losing the Space Race with the Soviet Union.

Four years earlier the Soviet Union had successfully launched their first satellite, Sputnik 1, and on April 12, 1961, Russian cosmonaut Yuri Gargarin became the first man in space.

On September 12, 1962, President Kennedy confidently proclaimed “We choose to go to the moon in this decade” and with these words the Space Race was further intensified.

An excerpt of the famous speech reads as follows:

We choose to go to the Moon! We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard; because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one we intend to win, and the others, too.

– John F. Kennedy, Rice Stadium, Houston, Texas.

How Omega Got to the Moon

On October 3, 1962, astronaut Walter Schirra took his personal Omega Speedmaster CK 2998 aboard Mercury-Atlas 8 (Sigma 7) and that same year NASA purchased examples of a number of commercially available chronograph wristwatches to evaluate their use for the Gemini and Apollo Programs.

Among the purchased brands were Breitling, Rolex and Omega, and others that produced mechanical chronographs.

The selection was quickly narrowed down to 3 brands for tests: Rolex, Longines-Wittnauer and Omega.

The Tests

The watches were exposed to a series of extreme conditions including high temperature, low temperature, humidity, shock, low pressure and high pressure.

The Tests

  1. High temperature: 48 hours at 160 °F (71 °C) followed by 30 minutes at 200 °F (93 °C)
  2. Low temperature: Four hours at 0 °F (−18 °C)
  3. Temperature cycling in near-vacuum: Fifteen cycles of heating to 160 °F (71 °C) for 45 minutes, followed by cooling to 0 °F (−18 °C) for 45 minutes at 10−6 atm
  4. Humidity: 250 hours at temperatures between 68 °F (20 °C) and 160 °F (71 °C) at relative humidity of 95%
  5. Oxygen environment: 100% oxygen at 0.35 atm and 71 °C for 48 hours
  6. Shock: Six 11 ms 40 g shocks from different directions
  7. Linear acceleration: From 1 to 7.25 g within 333 seconds
  8. Low pressure: 90 minutes at 10−6 atm at 160 °F (71 °C), followed by 30 minutes at 200 °F (93 °C)
  9. High pressure: 1.6 atm for one hour
  10. Vibration: Three cycles of 30 minutes vibration varying from 5 to 2000 Hz with minimum 8.8 g impulse
  11. Acoustic noise: 30 minutes at 130 dB from 40 to 10,000 Hz

The evaluation concluded in March 1965 with the selection of Speedmaster, which not only survived the comprehensive tests, but also did it while remaining largely within 5 seconds per day rate.

As a result of the tests NASA supplied each of the Apollo astronauts with a standard issue Omega Speedmaster Professional manual-wind wristwatch together with velcro-strap.

What’s remarkable about this decision is that unlike almost all other Apollo equipment, the Speedmaster was neither designed nor developed for use specifically by NASA or space exploration in general.

In fact the watch had been on sale in retail outlets in all of USA from 1957 first as the “Speedmaster” and later as the “Speedmaster Professional”.

The Man Behind the Tests

James H. Ragan worked in aerospace engineering for NASA and ended in 1999 after a 36-year career. He was the man responsible for Apollo equipment and also conducted the exhaustive tests of the chronographs purchased in 1962.

In the magazine WatchTime of June 2009, James H. Ragan is quoted as saying:

We conducted a number of rigorous tests and at the end of them all only Omega was left standing. Rolex failed primarily on account of the humidity test. Its watch’s hands became bent at high temperatures and got stuck. The crystal of the Longines watch got loose several times and the movement stopped working, too. The Speedmaster passed all the laboratory tests and exhibited the best reliability.

– James H. Ragan

Omega Speedmaster Professional Specifications

Since its introduction in 1957 the Speedmaster has been undergoing few changes.

Until 1968 it was powered by the calibre 321 which was later changed to calibre 861.

This was replaced with an enhanced version when Omega introduced a high-grade rhodium-plated finish on the movement, resulting in calibre 1861 and the more embellished 1863, both of which are hand-wound.


  • Chronograph
  • Tachymeter
  • Small seconds
  • Transparent case back (only calibre 1863)
  • Special box & accessories


  • Between lugs: 20 mm
  • Bracelet: Steel or Leather strap
  • Case: Steel
  • Case diameter: 42 mm
  • Dial color: Black
  • Crystal: Sapphire (calibre 1863) or Hesalite (calibre 1861)
  • Water resistance: 5 bar (50 metres / 167 feet)
  • Calibre: 1861 or 1863

Sapphire or Hesalite?

There are four main variations of the Omega Speedmaster Professional and the difference is mainly about the crystal and the bracelet material.

Whether you prefer bracelets made of steel or leather must be a matter of personal taste.

The choice of crystal is a less trivial consideration though.

The model powered by the calibre 1861 differs from the model with calibre 1863 in two ways. The 1861 model has a Hesalite crystal and the 1863 model has a Sapphire crystal.

The model with Sapphire crystal also has a transparent case back.

So which one to choose?

Models with Sapphire crystal cost about $1,000 more than models with Hesalite crystal and that may be sufficient information to settle that question for some.

But other than that both materials have their advantages as well as disadvantages:


  • Harder material, scratches less likely.
  • Optically clearer.
  • Easier to chip and/or crack than Hesalite.
  • Scratches harder to get out.
  • Replacement cost of crystal is more expensive than Hesalite.
  • More reflective.
  • Speedmaster watches worn on the moon didn’t have Sapphire crystal.


  • More original to the watches worn on the moon.
  • Scratches are polished out easier.
  • Less reflective.
  • Replacement cost of crystal less expensive than Sapphire.
  • Picks up scratches easier.
  • More distortion and less optical clarity.

When you buy the updated version of the ‘Moonwatch’ Omega includes a velcro strap to remind the customer of its association with NASA’s Space Programs in the 60s.

A truly legendary watch.

Check the price for the model with Hesalite crystal (311.


Image credit: Omega.

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Claus is a laboratory technician, autodidact guitarist, songwriter, music publisher, co-founder of App Division ApS, dad of fraternal twin boys, Sci-Fi lover, incarnated Mike Oldfield fan, pro world peace and an incorrigible coffee addict.

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