Seiko Astron GPS Solar SSJ013J1

Imagen: Seiko, web oficial

The storyWhy this reference matters

The Astron 35SQ was unveiled in Tokyo on 25 December 1969, after ten years' work at Suwa Seikosha. Inside was a quartz oscillator, a hybrid integrated circuit and a stepping micromotor; outside, eighteen-carat gold. The first hundred sold out in a week. The name was picked for its space-age ring, which was the language of those years, and from that point the mechanical watch stopped being the only business in watches.

Seiko parked the name for more than four decades and brought it back in 2012 for another first: the first mass-produced wristwatch that set itself by reading GPS satellites and ran on nothing but light. The underlying idea is the one from 1969 — put the most accurate time reference available on a wrist — and what changes is where that reference comes from. The trouble with those early GPS models was bulk, and that became the work of the following decade.

The SSJ013J1 belongs to the 2023 redesign, the one that introduced the 3X62 calibre and brought the family down to twelve millimetres tall. The titanium case gave up its round shapes for an irregular octagonal bezel — the sides are not the same length — and the bracelet became integrated. Three independent motors drive hours, minutes and seconds, which is why the watch changes time zone in about three seconds instead of dragging the hands half way round the dial.

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IdentificationHow to tell it apart

The quickest tell is the bezel: eight faces, none of them alike, brushed on top and polished on the flanks. Below it, an integrated titanium bracelet with a fourteen-millimetre attachment, so there is no strap swapping here. The blue dial carries a pressed relief that evokes quartz crystals, a nod to the original Astron, and a multifunction subdial at eight.

Within the series, the SSJ013 is the one in natural titanium with a blue dial; the SSJ014 has a rose-gold-coloured bezel coating and a grey dial, and the SSJ015 goes all black. If the watch in front of you measures 41.2 mm across, 12.0 tall and 48.5 lug to lug, you are in the 3X62 generation and not one of the thicker earlier ones.

The case back screws down and the calibre is marked 3X62: ten jewels, a perpetual calendar programmed to 28 February 2100, aeroplane mode and accuracy of ±15 seconds a month when it goes a while without seeing a satellite. Water resistance of 10 bar, sapphire with a super-clear treatment, and a folding clasp with quick adjustment.

CollectingWhat collectors check

A solar watch has no battery to change, but it does have a rechargeable cell that ages, and that is the part a service centre ends up replacing after enough years. Buying used, leave the watch in the light for a while and check the reserve indicator climbs. If it stays stuck on low in direct sun, price in a repair.

The fourteen-millimetre lugs and integrated bracelet are a decision for life: there are no practical replacement straps and loose links are hard to track down. Count the links and ask for the maximum wrist size before you buy, because lengthening an integrated titanium bracelet is not a problem you solve with a spare NATO.

The titanium carries a super-hard coating, which handles rubbing far better than bare titanium but, once marked, will not polish out without eating through the layer. Favour examples with a clean bezel, since that is the area that gets hit first. And check that manual signal reception works next to a window: without GPS the watch still runs, but you lose half the argument for owning it.

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