The remarkable achievement of the Seiko Quartz Astron lives on.

Governing a watch’s accuracy is the oscillator. That accuracy is improved the more the oscillation frequency is raised had been known since the time of Abraham-Louis Breguet. In the 1950s, some watchmakers had been able to dramatically improve the normal usage accuracy of wristwatches by adopting this approach. As long as a watch had heavy parts such as the balance wheel, however, further improvement was difficult. Watchmakers thus turned their attention to a technology that runs a current through a quartz crystal to control the accuracy of its oscillations. They saw that, theoretically, using a small crystal, it should be possible to raise the number of oscillations to several thousand times more than a mechanical watch.

In 1959, Suwa Seikosha (the current Seiko Epson) and an affiliate of K. Hattori& Co. (today, Seiko Watch Corporation) set about developing a quartz movement running on a 1.5V battery. Eventually the prospect of mass production came into view, as the company devised a method of forming the crystal oscillator by hydrofluoric acid using a photo-lithography technique, while suspending the oscillator in a vacuum capsule to protect it from shock and controlling the effects of temperature changes by means of a newly developed thermo-variable condenser.

In 1963, Seiko introduced the Crystal Chronometer, a quartz-controlled table-top clock. The following year, Seiko dominated the quartz deck chronometer category at the Neuchâtel Observatory competition, winning the 2nd to 7th place awards. Next, the company aimed to make this technology smaller. The quartz pocket watches entered in the Neuchâtel Observatory competition won the 2nd to 5th place awards in 1966 and 1st to 5th places in 1967.

The issues with quartz crystals had been overcome, but high hurdles remained on the way to greater compactness. The motor that turns the quartz oscillations into hand rotation was big, both in size and power consumption. Suwa Seikosha devised a distributed arrangement for the rotor and stator of the motor to save space. For the motor coil, made of 20µm copper wire wound 20,000 times, a six-pole stepper motor was developed that rotates the motor 60 degrees at a time by means of one electrical pulse per second. The result was a smaller motor with total consumed current of only 18µA.

In 1968, K. Hattori’s President, Shoji Hattori, seeing the development progress, shut down the tuning fork watch project that had been going on in parallel and told his team that he wanted them to achieve the commercial release of a quartz watch within one year. The development team, led by Tsuneya Nakamura, managed at last to create 20 watches by December 1969. The name given to the watch was Astron. Shoji Hattori chose a name that resonated with the language of the ‘space age’ for the world’s first mass production quartz-controlled wristwatch.

In the ten years that followed the creation of the Quartz Astron, its technology transformed people’s concept of time, eventually paving the way to the development of digital devices. Promoted under the headline, “Someday, all watches will be made this way” the Seiko Quartz Astron’s successors changed the horological world.

The second generation Seiko Astron is a GPS solar wristwatch that was released in 2012.
While the new Astron has functions and capabilities that far exceed those of its 1969 predecessor, the name Astron was chosen to demonstrate the importance of the GPS Solar technology that it contained and to highlight its high accuracy which was just as revolutionary as that of the first Quartz Astron.

The original Astron released in 1969 was about one hundred times more accurate than the standard mechanical watches of that day. It was accurate to within ±5 seconds per month. Thereafter, Seiko continued to raise quartz watch accuracy, so that, today, some Grand Seiko watches with the 9F quartz movement are accurate to within ±5 seconds per year.

What technologies were researched before this level of accuracy was achieved? One was the radio-controlled watch. In 2004, Seiko released a radio-controlled timepiece, adjusting the time based on standard time signals. In theory, a radio-controlled watch using an atomic clock as its reference should have outstanding accuracy; but Seiko was also aware of the limitations of this approach. Since there are only four countries in the world sending out standard time signals, it may not be possible to obtain the accurate time in countries beyond the reach of these signals.

The company then set out to develop a watch that could achieve accuracy anywhere in the world. The focus of these efforts was on a satellite watch synchronizing to time signals received from GPS satellites rather than using standard time signals transmitted from earth stations. Seiko Epson had already developed equipment for determining location by GPS, but incorporating this functionality in a wristwatch was seemingly impossible. The power consumption when receiving signals from a GPS satellite was around 200 times that of a radio-controlled watch; moreover, a huge antenna was necessary for accurate reception. Incorporating such functionality inside a wristwatch would require further downsizing and power saving. The challenge was exactly the same as that faced by the team that made the original Astron.

Just as a number of technical innovations made possible the first Astron, three elements enabled development of the satellite watch.

With a compact ring antenna for receiving signals and ultra-power-saving GPS module, it has the look of a completely normal wristwatch as well as excellent signal reception. In 2012, Seiko succeeded in launching the world’s first production GPS solar wristwatch. And the name it chose for this watch was Astron. While the functionality of the GPS Solar Astron far exceeds that of the 1969 original, the two are very much alike, in being the results of continuous drives to reduce size and power consumption and in achieving new standards of accuracy.

The first of the new Astron watches, the 7X Series, that was released in 2012, had an appearance like no other, to emphasize the uniqueness of its technology. The 8X Series of 2014, however, had a smaller outer diameter and had a more mainstream appearance. The 5X Series, launched in 2018, went further still with its exterior look showing no sign of the high functionality within. What’s more, when synchronizing, it receives time signals in just 3 seconds. The new Astron followed a path of continuous enhancement similar to that of its predecessor. The outcome of this journey at the present point in time is the new 3X Series released in 2019. As the world’s first women’s GPS solar watch, it no longer has even a single aspect in its exterior design that reveals its extraordinary functionality.

Just as the quartz watch advanced to the point where high accuracy became taken for granted, today’s Astron has made ultra-high accuracy across time zones an everyday reality. What the new Astron has brought about is truly a “Second Revolution.”