Seiko Spring Drive Spacewalk

Today October 12th 2008, Richard Garriott became the sixth private space explorer. Whats this got to do with a blog about big watches? Well during his flight on the International Space Station he will be wearing a 53mm Seiko Spring Drive watch, specially designed and built for the mission. Originally he was going to do a spacewalk, and very cool it would be to be the first private individual to do so. Last I heard it was cancelled. So here's a much longer and more detailed entry than usual in honour. This is the blurbage from the press release:

Why SEIKO Spring Drive?

The challenge of making a watch that could operate not only during a space flight but also outside on a spacewalk is a daunting one, and is precisely the kind of challenge that brings out the best in SEIKO's engineers. The first decision to be made was on the type of movement to be used. Without special treatment, battery-operated instruments are not appropriate for a spacewalk for safety reasons. Thus, quartz movements were not considered. The choice was therefore between mechanical and Spring Drive. The choice was decided by the need for safety and accuracy. As the watch will be exposed to a range of temperature from minus 20 degrees Celsius to plus 70, accuracy at extreme temperatures was the critical factor, and no mechanical watch can retain its accuracy in these conditions, because of the inherent instability in these conditions of the traditional escapement which regulates the time in all mechanical watches. Instead of a traditional regulator, Spring Drive has a Tri-synchro Regulator, an entirely new regulator that uses and generates mechanical, electrical and electromagnetic power, and is less affected by temperature variations. Thus, Spring Drive was selected as the perfect mechanism for the task.
The Spring Drive Spacewalk

The SEIKO Spring Drive Spacewalk has been custom designed and built with Richard's mission in mind. The mission of SEIKO's engineers was to build a watch that was light, air-tight, strong, easy to read and easy to use, as well as safe and accurate.

i)The air-tight case
Because of the vacuum of free space, the watch case needs to be completely air-tight. Based on SEIKO’s long experience with Divers watches that can withstand pressures up to 1,000 meters, Spacewalk was designed with special features that will guarantee air-tightness. In addition, to maintain the air-tightness in the huge temperature changes that occur in the vacuum of free space, and especially in cold temperatures, it was necessary to develop a new type of gasket using a rubberized material.

(ii)The lightness of High-intensity titanium
Everything to be taken into space needs to be as light and as strong as possible. High -intensity titanium was chosen as the case material because it is 40% lighter than stainless steel.

(iii)The optimum balance of lightness and wide dial-opening
The next challenge was to make the watch both as light and as large as possible. The case was designed for minimum volume but maximum dial opening size, to ensure quick readability. The solution was to build a case with recessed sides, but this required a new engineering solution, using a CNC machine that SEIKO developed in-house. This process reduced the volume of the case material by 30 %. With this process, a case was created that has the optimum balance of strength, lightness and wide dial opening.
(iv)The most readable dial.

Richard needs to be able to see time and elapsed time at a glance. After many dial designs were tested, a new layout, with the chronograph dials at the top, was selected. The hands and hour markers were designed expressly for this watch, and additional layers of SEIKO’s Lumibrite material were used. The dial is now at least three times brighter than a normal luminous watch.(v)Maximum ease of use
Richard’s hands will be protected, of course, by thick gloves. He therefore needed the buttons to be over-sized so that they can easily be used and they are placed at the top of the case to be more readily accessible.

Here's the specification:

• Caliber: Spring Drive Chronograph 5R86
• Case: High-intensity Titanium
• Diameter 53mm (12-6h) , 48.7 mm (3-9h)
• Thickness 15.2 mm
• Weight 　 92.5 g
• Glass: Sapphire crystal with anti-reflective coating
• Water resistance: 10 Bar
• Bracelet: The final specification is yet to be decided. SEIKO is now working with the Russian Federal Space Agency on the optimum design.
• Spring Drive Chronograph Caliber 5R86:
• Hour, minute and second hands with calendar
• GMT hand
• Power reserve indicator
• 50 jewels
• Movement Diameter : 30.0mm
• Thickness: 7.6 mm
• 416 parts
• Power reserve : 72 hours with/without chronograph function in use
• Chronograph to 12 hours