The Weapons of the Goliath

The Martian Goliath Mk III and IV play a major role in both the show and the books. The armor enables the carrier to project heavy direct and indirect firepower against both ground and air targets during both surface, shipboard and space operations. First seen in season 2, episide 1, it is featured repeatedly during both seasons 2 and 3, before returning in season 5.

Though a fantastic piece of kit for the MCRN and the MMC, there are some obvious issues with the weapons it employs, which will be discussed below.

First of all – the guns on the armor. In the books the gatling guns in the Goliath suits are referred to as 2 mm weapons firing armor piercing ammunition at a rate of more than 3000 rounds per minute, and with a muzzle velocity of more than 1000 meters per second. In the show, these are clearly not 2 mm barrels anymore. Instead, the size of the ammunition and the muzzles seen on the weapons carried by Bobby and her team is more consistent with the 6.25 mm caseless ammunition we see Bobby using in Season 3.

On the one hand, a 6.25 mm projectile makes more sense than the 2 mm mentioned in the books. Even with the low gravity and air resistance on Mars, it is just not possible for a 2 mm projectile to have the mass, and therefore kinetic energy to be effective in any way, shape or form beyond point blank range. The smallest bullet in regular use today is the 4.6 x 30 mm used with the Heckler & Koch MP7, but even that is only effective out to between 2-300 meters as the relatively light projectile loses energy quite quickly, despite their relatively high speed (around 700 m/s). By comparison, a 2 mm bullet would be like firing a sewing needle, which would rapidly lose both energy and stability once fired.

On the other hand, 2 mm ammunition would have solved another issue you will have with 6.25 mm, which is ammunition capacity. It is hard to judge the size of the cartridges we see, but my guesstimate is that they are around 4 cm in length and just under 1 cm in diameter, comparable to the ammunition used by the MP7. For weight, we can also just guess – the only comparable caseless ammunition in recent history is the prototype for the German G11. While larger overall, it had a smaller projectile, coming in at a total weight of 5.2 grams. If we allow for some futuristic Martian tech, and assume they are able to keep the overall weight down even with the a larger 6.25 mm projectile, this would mean that carrying the 3000 cartridges required for one minute of sustained fire would add about 15 kg of weight to the suit.

And while this might be acceptable, an ammunition belt carrying 3000 cartridges would end up being more than 42 meters long (as the belt we see in the show appears to hold 7 cartridges per 10 cm). For scale, that is more than 20 times the hight of a Goliath suit as seen on the show. There is just no way that would fit in Bobby’s otherwise compact suit. If instead the suit carries ony 1000 cartrides, her gun would only have enough ammunition for 20 seconds of sustained fire. Of course, it is quite possible that the gun in the show has a much lower rate of fire, but even so we are looking at 1-2 minutes at most before they are dry, and with no obvious or easy way of reloading the ammunition while in a firefight. This really doesn’t sound very practical, unless you are expecting engagements to be extraordinarily short.

The only time we get a clear indication of ammunition capacity is in season 3, episode 6, during the chase of the Io hybrid. During a six second burst, Bobby appears to expend more than 10% of her total ammunition load. It is hard to read the number of rounds shown on the right – it looks like it says “5000” as max capacity, but I do not quite see how that could be possible.

I am just going to mention one more issue with the suit design – the exposed ammunition feed, which I highlighted several times in my recap. Mars is a dusty place – I mean, Martians are literally referred to as “Dusters.” This kind of environment would be a problem for any piece of machinery, but even more so for a high-speed automatic weapon. With an exposed feed like this, you would be sucking in and chewing sand, dust and stones at an alarming rate – practically begging for everything to jam up.

This is why the few modern equivalents we see for this kind of ammunition feeds are enclosed in some way – either fully or partially. I am surprised the show runners didn’t use something like this on the Martian power armor.

But there is one weapon on the suits that I really do like, and that is the RPGs carried in a pod on Bobby’s back. This is the first man-portable missile system we see used in the show, and it is a good one! Crucially, it eliminates the issue of obstacles between you and your enemy – the RPG can just pop up, re-orient itself and then fire from an appropriate angle, using targeting information from either your own sensors or from data supplied from others. What makes this more useful here, is that you are fighting in an environment where everyone is protected within armored suits, which means you would not have to worry about the backblast injuring your fellow soldiers.

Real World Inspiration

There are a few modern day equivalents of the kinds of weapons we see on the suit. A US company has designed what it refers to as the XM556 “Microgun”, a small, hand-held gatling gun firing 3000 5.56 mm rounds per minute. As you can see from this short video, you would kinda need a suit like the Goliath to have any chance at controlling this type of weapon!