Would a Mechanical Watch Work in Space?

Watches have been worn beyond the troposphere. However, some watches have seen the moon and other parts of space that most humans don’t even get to experience. Although most people know the Omega Speedmaster as the moon watch, many other watches have been to outer space. The question is, do mechanical watches work in space?

A mechanical watch will work in space. Theoretically, it would also be more accurate in space. The gravity on earth has a negative impact on timekeeping accuracy, as it’s “pulling” in the timekeeping mechanisms causing friction.

Due to the pulling by gravity in the balance spring and pivot, friction is created, which will create instability in the timekeeping. You might have heard you can lay your watch dial up, dial down, on the crown or opposite side of the crown at night to make the watch go faster or slower. This has to do with the friction that is created when the watch is turned on different angles.

Would a Mechanical Watch Work in Space?

How Gravity Affect Mechanical Watches

To understand how gravity can affect a mechanical watch, we first must have a basic idea of how the balance spring (also called a hairspring) works.

A balance spring is a spring that is connected to the balance wheel. The balance spring forces the balance wheel to oscillate with a resonant frequency. Hence it’s controlling the speed of the gear train, thus the speed of the hands.

A mechanical watch is affected by gravity in significance to the position of the watch. The highest amount of friction is reached when the watch is in a vertical position. The oscillations of the balance spring slow down as friction increases making the watch run slower.

When the balance spring is placed in different positions, it keeps time different. In one position, it can be +4 sec/day, while in another position, it could be +6 sec/day.

This variance in timekeeping is due to the effects of gravity, which increases the friction inside the watch. When friction increases, the oscillations is slowed down.

Even with the very sophisticated laboratory-made jewels possible to manufacture, the friction can’t be made low enough to ignore gravity’s effects. This is also why tourbillons were invented (source).

The highest amount of friction is reached when the watch is lying on its side. Hence either on the crown or the opposite side of the crown. If you have a watch that is running a bit fast, you can put the watch on the side while sleeping to prevent it from gaining too much time.

Does a Mechanical Watch Work in Space?

Whether you believe humans have been to the moon, space, or anything higher than an airplane, watches have been worn microgravity before, and with great success.

The Omega Speedmaster Professional (Ref. 105.003) is known as the first watch on the moon. Before Omega was selected as the official watch, NASA conducted thorough testing of 10 brands (source).

After extensive testing, the Omega Speedmaster Professional got the NASA seal of approval for manned space missions.

Pasts of the testing included high and low temperatures, compression, humidity, shock, acceleration, decompression, and vibrations. None of which includes gravity.

Gravity is pulling the balance spring
Gravity is pulling the balance spring

NASA’s engineers know that gravity is stronger on earth. Therefore, the effect that would make gravity play a role in the mechanism would cease to exist when the watch enters zero gravity.

On earth, gravity will pull the balance spring towards earth, causing a natural increase in friction inside the watch’s movement.

However, as the watch enters zero gravity, everything will, in theory, float individually. This means the only things that hold the watch together is screws. However, it also means that the balance spring is not exposed to a constant gravity pull, creating friction.

In theory, this also means the watch would start to gain time while being in space since the friction is lower inside the watch’s mechanism due to the lack of gravitational pull.

What Watches Have Been Worn to Space?

Today, whether a watch can be worn to space or not is nothing newsworthy. By now, a lot of watches have been in space.

Therefore, you will have a difficult time trying to find the common choice of watches for current space missions. However, with some thorough digging, it’s possible to find that Seiko and Casio is among the standard choices.

Watches worn to space:

  • Omega Speedmaster
  • Sturmanskie (special ordered – No commercially available model)
  • Breitling Navitimer
  • Heuer chronograph
  • Strela (Poljot) Voskhod Chronograph
  • Rolex GMT Master
  • Fortis watches (Official Russian space watch brand)
  • Sinn 142 chronograph
  • Seiko “Pogue” 6139
  • Fiyta Spacemaster
  • Bulova chronograph
  • Accutron Astronaut

All these watches have been worn in space at least once (source). However, watches such as the Omega Speedmaster and Strela Voskhod has been worn in space multiple times and in different variants (source).

Although all the models listed above is mechanical, quartz watches are the norm today. Since quartz watches were invented, they have replaced mechanical watches in so many aspects (source).

Would an Automatic Watch Work in Space?

Having a watch in space is remarkable by itself. However, since Omega launched its manual wound Speedmaster watch to the moon together with some astronauts back in 1969, many have wondered whether automatic watches could work as well.

Automatic watches will work fine in space. If the wearer of the automatic watch is moving, the rotor will also keep functioning despite zero-gravity. Newton’s third law determines the functioning of the rotor. Automatic watches work by motion, not gravity.

However, a self-winding watch will not wind as effective in space as when exposed to gravity. Since zero-gravity makes the rotor weightless, it “floats” like the rest of the components. However, a motion will still cause the rotor to move, explained by Newton’s third law.

Newton’s third law says that for every action, there is a reaction. Think of something as simple as boxing. When the boxer hits the opponent, he creates action by the punch. When the punch lands on the opponents, the reaction happens. The reaction is a sudden stop to the boxer’s punch movement.

The action (the punch) moves from the boxer’s body to the opponent’s body, which is why boxers are pushed back when hit by a punch.

For every action, there is an equal and opposite reaction.

Newton’s third law

Why Won’t a Regular Watch Keep Time in Space?

In the early parts of the school, we learn about space and what has happened in space since we started going. In our education of the solar system and space missions, you have probably never thought about the earth’s rotations in contrast to the orbiting space station.

When orbiting the earth, the day-night cycle is very different. It takes 90 minutes for the space station to orbit the earth, giving a 45-minute day and 45-minute night. Therefore, the traditional 24-hour watch will not work to track time in space.

While we have watches made for normal commercial air traffic (GMT), stopwatches (chronographs), diving (unidirectional bezel), but not a watch type dedicated to space.

Making a dedicated space watch is especially difficult because the day-night cycle depends on the orbit. When being on the ISS, the day-night cycle is 90 minutes, but being at different heights of orbit will change the day-night cycle duration.

Astronaut with watch

When working on the international space station, multiple nationalities are typically working together. E.g., the International Space Station (ISS) consists of members from Canada, Japan, Russia, the USA, and a bunch of European countries.

All crew members have to follow a common time zone to have a regular work routine.

Final Thoughts

Mechanical watches work just fine in space, and we know this thanks to science and having the watch physically in space. Before sending watches with the astronauts to space, NASA did some extensive testing to find a suitable watch.

The whole history of finding a watch equipped to be in space is very fascinating. The only watch brand good enough to make the official NASA stamp of approval for the moon landing back in 1969 was Omega.

Since then, numerous mechanical, automatic, and quartz watches have been worn to space. This shows that all types of watches work in space and, more importantly, in zero gravity.

Jonas Henriksen

AllInWatches is founded by Jonas, who has a great interest in mechanical watches. All aspects of manual and automatic (mechanical) watches is a big interest and have been a passion since 2015, where the first automatic watch was purchased. Seeing the transparent case back and discovering the heritage of watchmaking piqued an interest in horology.

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