It is common knowledge that German astronaut Reinhard Furrer wore a Sinn 142 during his stay in space for the German Spacelab "D1" mission as part of the STS-61A Space Shuttle launch in 1985. For a very long time, his Sinn had been credited as the first automatic chronograph in space until new evidence recently gave that title to Seiko.
While Sinn also based some of its marketing on that achievement, I always had some doubts. Not that a Sinn did go to space, but rather about which particular model made the trip. So now I will share my thoughts on this topic, and I welcome any feedback of new elements you might have to either confirm or invalidate my theory.
First, let's have a look at the well known picture of Reinhard Furrer in the Space Shuttle:
On his left wrist is clearly visible a large watch with a black PVD coating, an option made available by Sinn on several of its watches, including the 142. And it sure does look like the latter. But my problem with that version of history is that we never saw any other pictures of this watch, let alone any kind of close-up shot. Given the importance of this timepiece in Sinn's marketing, it is not unreasonable that they would have tried to have further material to put forward, and that well before Reinhard Furrer's tragic death in 1995.
Also, an other details caught my attention. The 142's caseback has an engraving commemorating the D1 mission, but it refers to the watch as "model 140/142". For those of you who don't know, the Sinn 140 used the exact same case, but was powered by a Lemania 1341 movement that also featured a GMT complication. Definitely a close cousin to the 142, but not the same watch though. This prompted me to dig a bit deeper, until I found a better resolution version of the picture above, from which I cropped the following close-up:
Not supremely detailed, I admit, but enough so that we can draw a few conclusions. The first one is that the watch visible on this shot is NOT a Sinn 142. The element that allows me to be so sure is located at 12 on this watch's dial: the luminous marker. Because of the Lemania 5100's 6-9-12 subdial layout, the Sinn 142 does not have such a luminous marker, as shown on the following picture taken from Sinn's own promotional material:
On the picture above, it is clear that the presence of the 24 hour register, typical of almost all Lemania 5100 chronographs, does not leave room on the dial for the kind of large luminous marker visible on Reinhard Furrer's watch. That is why I can confidently say that, based on the photographic evidence, this chronograph was not a Sinn 142.
So the next logical step is to consider the other possibilities for what this watch might have been. As I mentioned before, a likely contender is the Sinn 140 with its Lemania 1341 automatic movement. But there too, there is a problem. Let's have a look:
Photo by Chuck Maddox
First of all, there is an obvious issue with this theory: all the Sinn 140 I have seen had contrasting subdials, just like Chuck's example above. And such an characteristic should be plainly visible on the Space Shuttle picture. Then there is the small date window, as the Lemania 1341 only provided date display. On Reinhard Furrer's watch, the window seems larger, probably to accomodate day and date.
So it is my belief that there is only one candidate left, a watch that was briefly produced by Sinn before the introduction of the 142 and which, I believe, was known as model 141:
This chronograph used a less common variant of the Lemania 5100 family, the calibre 5012. Apart from the absence of a 24 hour subdial at 12, leaving room for a large luminous marker, the 5012 beats at a slower beat (21,600 bph) than its more famous cousin. But it also does have day and date display, and its apparence is therefore fully consistent with what is visible on the picture of Reinhard Furrer's watch.
In the end, my theory is that by the time the D1 mission took place, the model 141 had already been replaced by the 142 in Sinn's range. So when the picture of Reinhard Furrer wearing a Sinn in space surfaced, Sinn had to seize the opportunity, but on the other hand had to advertise the family of chronograph and not simply a specific model which had been discontinued. They sure were happy about the ambiguity, but their stance was certainly not worse than Omega's regarding the current Moonwatch model. This would therefore explain the puzzling "model 140/142" engraving on the back of the 142s produced after 1985.