The Barrelhand ‘Monolith’ Is An Engineer’s Vision Of An Astronaut’s Watch

Barrelhand is a small independent watch brand based in San Francisco, and the Monolith is a watch which has been years in the making. The brand was founded by Karel Bachand, a former NASA engineer, who started the company all the way back in 2014, and the ideas behind the Monolith have been percolating ever since. Barrelhand has just one previous watch to its name – the Project 1 – and with the Monolith, Bachand decided to start with a clean sheet of paper, and make a watch for the next generation of crewed space flight, lunar, and interplanetary exploration.

The Monolith is a relatively small watch, at 38mm x 11.8mm, but aside from the size there is nothing conventional about the watch (except, arguably, the movement, about which more in a minute).

Each part of the watch has been designed around a set of criteria derived directly from the environment it would encounter during long duration space exploration, and the processes and materials used to make the watch reflect the pursuit of those considerations – including the suitability of the watch for EVA (spacewalks, and other activities that require egress from a spacecraft, including, presumably, exploration of the surface of the Moon and Mars). Such a watch should be precise, and legible of course, but it must also be able to resist corrosion, extremes of heat and cold, magnetic fields and radiation, and it should ideally be light and comfortable to wear.

The Case, Crystal, And Crown

The case looks like it’s made of titanium but it’s not. It is produced by 3D printing, and uses an aluminum alloy called Scalmalloy, which has been specifically designed to be AM compatible. AM stands for additive manufacturing, or 3D printing, and Scalmalloy is a combination of aluminum, magnesium, and scandium – the latter is a rare earth element which is used in small amounts to produce high-strength aluminum alloys. In addition to having been formulated from the ground up for additive manufacturing, Scalmalloy is also extremely strong for its weight – it’s about 40% lighter than titanium, with a tensile strength of 520 MPa (megapascals) vs. 240 MPa for commercially pure titanium alloys (although high-strength titanium alloys close the gap with Scalmalloy, and in some cases exceed it). Scalmalloy, significantly, lends itself to a wide range of shapes and applications, without the technical challenges involved in machining titanium, and it’s used here for its relative ease of manufacture, high corrosion resistance, strength, and lightness. One of the goals for the Monolith was making it as light as possible, given the still relatively high cost-per-gram of getting things into Earth orbit. A caveat here is that cost-to-orbit varies by several orders of magnitude depending on the mission profile, but the general point is that weight is a consideration.

The lugs of the case have a spaceframe design intended to offer strength with a minimum of mass and material, which is reflected in the overall case structure as well.

Up close, the material has the very slight grain you would expect from a 3D printed case. The watch is very light – the entire case (minus the movement) weighs just 6.5 grams. For comparison, that old stalwart, the Seiko SKX 007, with bracelet comes in at 142 grams on the OEM bracelet, while the Monolith’s total weight is just 31 grams, not including the strap. Scalmalloy also has good thermal insulation properties. For the Monolith, the surface has been anodized to produce a thick, scratch resistant aluminum oxide ceramic layer.The watch is, despite the fact that it doesn’t have a screw down crown, water resistant to 200 meters (and Barrelhand says it is also tested to 0 atmospheres as well, preventing egress of the atmosphere inside the case in a vacuum). It’s not visible in the completed watch, but there are also perforations around the interior of the case, to further lighten it without compromising structural integrity.

The crystal is made of synthetic sapphire, although again, it’s a specific type of synthetic sapphire – C-plane sapphire, which is cut parallel to the crystal c-axis, or long axis of the crystal. This gives twice the shatter resistance of standard synthetic sapphire crystals, and the material is coated with magnesium fluoride antireflective coating, which is more scratch resistant than conventional multi-layer AR coatings (it’s also less expensive to produce). The crystal is mounted on an L-shaped (in cross section) gasket for both water and shock resistance.

The crown is protected by crown guards and it is not a screw-down crown, which is an advantage as long as the gasketing’s robust enough to ensure good water resistance. Barrelhand rates the Monolith, as we’ve mentioned, to 200 meters (this is obviously not a concern for space flight, unless you live in the medium-term distant future in a Mars colony or an O’Neill cylinder with a good sized swimming pool or lake to splash around in). For all that screw-down crowns are the industry standard on sports and utility watches, they’re also certainly more fiddly, and are more prone to being damaged by owners cross-threading the crown when screwing it back in. In this case I think the non-screw down crown is a feature, not a bug.

The case is held shut with four Torx screws, which are also used to fix the springbars in place. Torx screws are widely used in the electronics industry, and they offer some advantages over standard slotted or Phillips head screws – they’re less prone to slipping and easier to align. Barrelhand points out that Torx screws, and therefore Torx screwdrivers, are in use on the ISS and are likely to continue to be commonly found on crewed missions, which allows the spring bars and watch case to be accessed without requiring a specialist watchmaker’s tool kit.

The case is also designed so that the gasketing system acts as a shock resistance system as well. The case is designed to allow the movement to tolerate shocks up to 3000 g, which is the requirement of ISO 1413, the international standard for shock resistant watches. To put this in perspective, most watches produced today fulfill the requirement for ISO 1413, so the antishock capabilities of the Monolith are in the “meets but does not exceed the standard” category. However, Barrelhand doesn’t stop there. ISO 1413 testing is designed to duplicate the shock a watch would receive if dropped a meter onto a hardwood floor; the Monolith also passes the more comprehensive and in some respects, much more rigorous Chronofiable A8 tests, which we’ll look at when we get to the movement.

The Monolith Dial

The dial of the Monolith brings together the expertise of RC Tritec, the supplier of Super-LumiNova to the industry, with Black Badger Advanced Composites‘ James Thompson, who has assisted in producing luminous dials for brands as varied as TAG Heuer, MB&F, and MB&F. Interestingly enough, F.P. Journe’s dial maker, Les Cadraniers, made the actual dial. The dial is made of two layers of DLC coated titanium, and the lume consists of blocks of luminous ceramic. A quote from the CEO of RC Tritec, Albert Zeller, on the development of the “Aerolight X1 Ceramic”:

“Over the last 2 years we worked closely together with Barrelhand to develop a ground up solution for their space application. They provided us with all of NASAs EVA specifications and together we created an entirely new construction and next generation lume composite fully equipped for the harsh conditions of space exploration.”

The dial is, I suppose, a kind of sandwich dial – the Aerolight X1 Ceramic is cast in a single block.

The development of the dial was informed by the need to have something chemically and structurally stable over the long term, and which would be essentially unaffected by ultraviolet radiation (UV radiation is four times greater during EVA than on Earth) and extremes of heat and temperature. As far as I can tell, the dial should look the same in a hundred years as it does now – there is nothing there which can be affected by corrosion or degradation from UV radiation.

If there are watch collectors on Mars in a century, they won’t be paying extra for tropical dial Monoliths because they won’t exist, ever.

The lume is among the brightest I’ve ever seen in any watch, thanks to the thickness of the markers, and it doesn’t take much exposure to sunlight to produce a visible glow. A fifteen minute stroll to the corner for groceries with the watch on my wrist, produced a glow bright enough to be instantly noticeable in my elevator afterwards; it’s right up there with other lume champs in my personal collection, including a couple of pieces from MING, my Seiko divers, and my Tudor Black Bay. At first, I thought that there was no visible branding on the dial at all but if you look closely, you’ll see that there is a stylized letter M for Monolith formed by the 12:00 marker.

The hands are filled with C3-X1 Super-LumiNova (the brightest available commercial grade).

The Movement: Sellita Caliber SW-300

The decision to use a mechanical movement over quartz arose out of several considerations – one of these was the question of battery life (which can be severely degraded by exposure to cold); the other had to do with the fact that while a quartz watch would in general be superior in terms of frequency stability and therefore, precision, the LCD displays in use on multifunction quartz watches from the X-33 to the Casio G-Shock, can be destroyed by temperature extremes. Here there are obvious tradeoffs in terms of functionality – a hundred dollar G-Shock gives you, among other things, a 1-100th-second chronograph, countdown timers, a perpetual calendar, and alarms, as well as proven shock resistance, all of which the Monolith sacrifices for the long-term reliability of an industry-standard mechanical movement.

The movement has been modified – the escape wheel and lever are made of a non-magnetic nickel phosphorus alloy, although the balance spring is still a standard Nivarox type. The use of a non-magnetic alloy for those two components won’t protect the balance spring from cumulative magnetism-induced changes to its temperature compensation, which is the biggest long-term issue with Nivarox alloy springs and which is one of the drawbacks to standard balance springs, which silicon balance springs are designed to protect against. I don’t think Sellita currently offers movements with silicon springs, although at least theoretically, you could get an automatic with a silicon balance spring from Kenissi, which however seems to reserve those for Tudor. Ronda just started producing a movement with a silicon lever, escapement, and balance spring – the new caliber R01, with an 80 hour power reserve, which might be of interest to Barrelhand moving forward.

As we already mentioned, the Monolith fulfills the requirements for shock resistance of ISO 1413, but the watch also passes the Chronofiable A8 test. The ISO 1413 test, which is one you may have seen being administered if you’ve ever visited a watch factory, is surprisingly low-tech – the watch sits on a stand and gets whacked by a plastic hammer swung like a pendulum; the actual shock reaches around 3,000 g, briefly.

This sounds as if it ought to catastrophically destroy the entire watch, but the actual exposure takes place over a very short period of time, and so while the peak force is high, the actual change in velocity over time is fairly low by comparison. The Chronofiable test, on the other hand, subjects a cased watch to a 21 day testing regimen which, according to the lab that administers it, simulates six months of actual wear on the wrist, during which time a watch might receive up to 20,000 individual shocks of varying intensity and in different directions. The test includes, as well, testing to temperature extremes and humidity, as well as testing the crown. The testing is destructive, with the number of watches tested depending on the production run.

The Monolith movement sits inside a free-floating aluminum case holder which is surrounded by two silicone o-rings (this is in addition of course, to the actual case gaskets and the L-shaped gasket providing water resistance and shock resistance for the crystal).

The complex case construction and interior antishock buffers are of course part of the larger overall project of making a watch in a wearable size that has enough shock resistance to pass what I can only describe as an improbably intensive and elaborate series of tests to qualify the watch for EVA. Before leaving the movement, though, it’s worth mentioning that it’s regulated to ±4 seconds per day (which improves on the COSC standard of -4/+6 seconds per day).

EVA Testing The Monolith

Considering how little time on average any watch used in crewed spaceflight actually spends outside during EVA (although it’s hard to generalize as the actual time depends a great deal on the mission profile) Barrelhand put a lot of work into making sure the Monolith is EVA-ready. Actual EVAs can last for a surprisingly long time, however – the record holders are all in excess of eight hours long, which would certainly try my patience. This means that if a watch has not been specifically optimized for that environment, that it might be significantly degraded in performance, especially with repeated excursions, and so Barrelhand has tested the Monolith in a regimen which was developed in-house, but based on the tests NASA used to qualify the Speedmaster. The in-house tests include:

• High temperature testing: 48 hours at a temperature of 160 °F (71 °C) followed by 30 minutes at 200 °F (93 °C).
• Low temperature testing: Four hours at a temperature of 0 °F (-18 °C)
• Temperature pressure chamber testing: 15 cycles of the regimen, pressure maximum of 1.47 x 10exp-5 psi (10exp-6 atm) with temperature raised to 160 °F (71 °C). The temperature shall then be lowered to 0 °F (-18 °C) in 45 minutes and raised again to 160 °F in 45 minutes
• Relative humidity testing: A total time of 240 hours at temperatures varying between 68 °F and 160 °F (20°C and 71 °C, respectively) in a relative humidity of at least 95%.
• Pure oxygen atmosphere testing: An atmosphere of 100% oxygen at a pressure of 5.5 psi (0.35 atm) for 48 hours (NB: Nasa ceased using pure 0² atmospheres in spacecraft after the Apollo 1 disaster; this test is on the agenda for final EVA validation but has not thus far been performed in-house by Barrelhand thanks to equipment limitations)
• Shock testing: Six shocks of 40g each, in six different directions, with each shock lasting 11 milliseconds.
• Acceleration testing: The test item shall be accelerated linearly from 1g to 7.25g within 333 seconds, along an axis parallel to the longitudinal spacecraft axis (note that this is far longer duration than the milliseconds-length testing for ISO 1413)
• High pressure testing: A pressure of 23.5 psi (1.6 atm) for a minimum period of one hour
• Vibration: Three cycles of 30 minutes (lateral, horizontal, vertical, the frequency varying from 5 to 2000 cps and back to 5 cps in 15 minutes. Average acceleration per impulse must be at least 8.8 g
• Acoustic noise testing: 130dB over a frequency range from 40 to 10,000 HZ, for a duration of 30 minutes (as with the oxygen atmosphere test, this is on the agenda but not yet done in house)
• Glass impact: 360 gram steel impact tip dropped onto the crystal from various heights

Barrelhand notes, “Monolith’s performance throughout EVA testing substantially exceeded both internal expectations and historical benchmarks. From extreme thermal cycling to multi-axial 3000 g impacts, there were no pressure or hardware failures of any kind, and a cumulative worst-case timing deviation of −57 seconds per day across the full test campaign. For context, the Speedmaster gained 21 minutes during decompression testing alone, an environment where Monolith only lost an average of 12 seconds per day across all 6 positions.”

This is where the complex case construction really shows its benefits; the actual description of the testing regimen is replete with math and diagrams, which I don’t propose to even try to reproduce here. For those interested, I suggest the Barrelhand article on EVA testing for the Monolith.

The NanoFiche Memory Disk Caseback

We now come to what is a unique feature of the Monolith, and we go from the purely practical, to a highly speculative exercise in creating a cultural connection to the history of deep space exploration and the imagined future of human space exploration. The back of the watch has, embedded in it, a pure nickel disk – the Memory Disk – which is laser engraved with text and images forming a kind of highly selective archive of human culture.

The engraved information includes 286 translations of the UNESCO constitution’s preamble; 106 artworks; the entire text in French of the original edition of Le Petite Prince, a visual (audio waveform) sound recording; a “universal metrics and navigation” section, which includes part of the map sent into deep space on the Pioneer and Voyager probes. The most notable piece of information, in the center of the disk, is a map showing the position relative to the Earth of fourteen pulsars, as well as an additional line pointing to the galactic center, for orientation. The pulsars are identified by a graphic representation of their periods of rotation. Some folks when this information was sent into interstellar space by NASA, questioned the wisdom of sending our home address to god knows who or what, but sometimes science isn’t about why, it’s about WHY NOT.

This is easily one of the most, if not the most, difficult to photograph features I have ever seen on the watch. Not having access to a microscope with digital output, I relied on a combination of a full-frame sensor in a Sony A7 III, and a Micro Four Thirds sensor in a ten year old Olympus OMD-EM1. The cameras were fitted with a 100mm Tamron macro lens and a 60mm Olympus macro with Zeiss optics, respectively. The latter is probably the best overall macro lens I’ve ever used, with excellent sharpness and contrast. Nonetheless, capturing any detail was difficult. The Memory disk is eerily beautiful, with some of the etchings fine enough to produce colorful diffraction patterns.

Resolution of the NanoFiche process is according to their website, 133,000 dpi, with the smallest features possible around 200 nanometers; this is the size of a small bacterium.

It was I have to admit, hair raising to see these features under magnification. The images are necessarily grayscale as they are essentially monochrome engravings of polychromatic artworks, but you can recognize the artworks easily despite that.

Everyone will have their favorites and I was pleased to identify, of course, Vermeer’s Girl with a Pearl Earring; Caspar David Friendrich’s Wanderer above a Sea of Fog (the first image in the series, visible up top) Goya’s Saturn Devouring his Children, just below and to the left; Delacroix’s Liberty Leading the People, to the immediate right of the Vermeer, van Gogh’s Starry Night (of course) and Mary Cassat’s The Boating Party. 

There are many others too numerous to list and anyway half the fun is picking them out yourself. You will not be able to see any detail at all with even a 20x loupe, however; I would recommend either a microscope or a camera with a macro lens fitted with extension tubes – the Laowa 24mm f14 macro Probe lens would give interesting results as well.

The Barrelhand Monolith: Design Goals And Design Achievements

This is undoubtedly the most unusual watch I’ve seen this year on several counts. It is first of all, absolutely obsessively thought through from an engineering standpoint. That it is also in some respects still a work in progress is a given, considering the goal, which is to explore the criteria by which you might evaluate a watch designed for long duration space missions as well as EVA. The testing regimen, while not yet something Barrelhand has the equipment to use in every aspect, nonetheless reflects the real-world environment that such a watch would encounter. The thoroughness with which everything from g-forces, acceleration and deceleration, vibrations, magnetic fields, and so on, have been considered in terms of how they might affect the watch, as well as possible solutions for remediating how such influences might damage the watch or adversely affect its precision, is remarkable.

Some watches feel as if they were designed, yes, to satisfy a consumer market demand; others feel as if they were designed as much to entertain fellow professionals, as to appeal to a collector. The Monolith feels as if it has been designed by engineers, for engineers, in a sense, although that’s not to say it might not be interesting to anyone curious about the evolution of mechanical horology seen from a holistic perspective that includes not just the movement, but the watch as a whole, and how it might be relevant in a highly technical and very unforgiving environment. Every part of the watch is designed with multiple considerations in mind. The case, for instance, is designed to be something that can be fabricated in microgravity and without access to conventional machine tools (although you do have to do the printing in an inert gas atmosphere); the alloy used was chosen for its strength and lightness, but also for its insulating properties; the design of the case was built around the need to provide a housing for the movement, as well as physical interfaces for the crystal, dial, crown, and caseback, which would improve resistance to extremes of temperature, air pressure, and vibrations and shocks.

Functionally the watch is almost impossible to fault (during the week I’ve been wearing it, it has been running well within its precision spec as well). I might wish for some sort of elapsed time or dual time functionality, but a chronograph would be overkill and a timing bezel, especially with enough gradations for it to be really useful, would produce additional visual clutter, introduce additional possible points of failure, and probably not add materially to the actual use case of the watch, which is to provide a ready, reliable orientation with respect to time, for long duration space expeditions.

While this is a watch which has been exhaustively conceived in terms of pure utility, paradoxically, it comes across as much more emotional and even evocative than you might think. That NanoFiche caseback is a testimony to the imagination behind the design. The Monolith is really a watch that defines its own genre – there are precious few mechanical watches designed, from the ground up, for use by astronauts. The NanoFiche inscriptions, however, also give the watch the air of a very convincing piece of hard science fiction. I thought, while I was wearing it, a lot about hard sci-fi classics like Arthur C. Clarke’s Rendezvous with Rama, where speculation remains firmly grounded in the laws of physics, while the action has at its heart, the irresistible romance of voyaging into the unknown. The name “Monolith,” of course, evokes another of Clarke’s works of fiction: 2001: A Space Odyssey, in which a monolith of alien origin drives human evolution towards its destiny as a spacefaring civilization.

There has been, since the watch was announced, some objections to the price, which at the time of writing is $9750. I think the almost incredible amount of thought that went into the watch more than justifies the cost. It’s a watch with less overtly obvious flash, but more actual intellectual – and, indeed, emotional content – than I’ve seen anywhere else recently, and it is a demonstration of the degree to which rigorous, modern technical engineering can reflect traditional horological values in a fresh new way.

The Barrelhand Monolith: Case, 3D printed Scalmalloy with type II anodization and “aircore insulating chamber,” 38mm x 45mm (lug to lug) x 11.8mm, with 20mm lug width; total weight 31 grams; 200 meter water resistance. Dial, DLC titanium two part construction, monolithic Aerolite X2 ceramic, seconds hand counterweighted to resist displacement due to shock; dial manufactured by Les Cadraniers de Genève (FP Journe). Crystal, lab-optic C-plane sapphire with Hytrel L ring for impact resistance. Movement, M1 caliber; Sellita SW-300 base, with nickel-phosphorus escape wheel and lever; 50 hour power reserve, running at 28,800 vph. Strap, elastic polyester with grade 5 titanium G-hook clasp. Memory disk, 19mm x 1.2mm, 1.4g, 3GB storage, using NanoFiche etching in collaboration with Stamper Technology. US price, $9750; next batch delivered Q4 2026. Find out more and reserve a Monolith at Barrelhand.com.