u/NightBeWheat55149

M17 BDU (Battle Dress Uniform)

Manufacturer:

Marineris Arms Logistics Corps, based in Valles Marineris, Mars. Adopted in: 2157 In use between: 2157-present (2308) In use by: UWS (United Worlds of Sol) Marine Corps, UWS Army (Limited use), undetermined amount of surplus gear in circulation, Nemesis Fortification Group (PMC)

In-universe context:

The M17 BDU is the slow culmination of decades in suit development, with the aim of making an EVA suit that's compact and mobile enough to be adopted in military use. It was originally commissioned by the UWS Navy as a new interior uniform for their crews on smaller craft like patrol vessels and corvettes, but showed promise for a combat role when ballistic tests were done. It was put into service in 2157, originally only for the UWS Navy and Marine Corps, but some branches of the UWS Army, the Martian and the Titan branches, adopted it for their special forces units. The uniform was tested on Mars, Titan, the radioactive ruins of Washington DC and Ganymede. As the design is over 150 years old, it is extremely common. A variant of the M17 BDU is still in UWS service, nations and organisations in other star systems rely on it, even the civilian sector employs surplus M17's for their rugged nature. Mercenary groups or irregular military often use these too due to ease of acquisition. This leads to common jokes and sayings that "Everybody uses an M17 variant, just with their own coat of paint". The mantra isn't 100% true, as of course some nations or groups have the means to design and manufacture their own suits. The current estimate for produced M17 BDU's is 60 million, but the exact number is unknown due to the amount of suits produced outside of MALC factories under license or copied.

Environmental specifications:

Can survive pressures between vacuum and 2 bar, but internal pressure should be regulated to allow for easy movement. Fabrics and armour have a thin aerogel layer for temperature insulation. With the internal mechanism, it can allow the user to survive temperatures between -200C and 80C within 1atm. The life support allows the user to operate independently of an Earth-like atmosphere for approximately 15 minutes. When entering a breathable atmosphere, the suit can reset the air filters for another 15-minute session. When combined with a proper EVA life support pack, the life support time can be extended to several hours. Radiation protection is adequate for most activities, but long term exposure is still unsafe. Cancer growth prevention meds are recommended when going through on EVA often, and good luck surviving a long time around Io.

Armour specifications:

The main plate is slightly flexible (Not a standard fabric, but enough for the user to bend and turn unhindered) and has a shear thickening fluid layer within. That property lets the armour absorb kinetic energy from impacts, preventing internal damage (Like a cracked rib). It can shrug off 9mm (and equivalent) pistol cartridges, might survive intermediate rifle cartridges (5.56x45mm NATO and equivalents) from the right angles, but a battle rifle round (7.62x51mm NATO, the UWS standard round) will penetrate. Not all surfaces are made of this material though. The shoulders and thighs are covered in the same fabric designed for survival and light puncture protection. The forearms and legs are have traditional non-articulated ceramic composite armour, as those areas can be used to attach equipment and they aren't as vulnerable to kinetic energy as the torso (They only have flesh and a single, relatively tough bone inside). The helmet offers protection similar to 20/21st century combat helmets, being able to block pistol rounds and potentially survive rifle hits with a combined ceramic composite/ST fluid build. The visor is vulnerable to most weapons fire, meaning headshots are lethal more often than not.

Tech integrated:

The visor has several features. To help with intense light from firefights or sunlight in vacuum, the polarisation level can change to accomodate the current situation. A HUD system is present too. It displays basic information like oxygen and electricity levels, ammunition count and a reticle for weapons (Provided that they have a compatible laser aiming module) and rangefinder data. Connected to the helmet's side camera, it can highlight targets based on IR readings, like an augmented reality headset. To prevent the likelihood of friendly fire, the helmets have and suits have an IFF tag that changes the highlight on friendly troops. A basic comms suite is present, allowing for communication over 20 kilometers away. Attachments are popular with the helmet system too, allowing for extended communications range, painting targets for air/artillery support, or optics that can spot targets far enough to turn infantry combat into near-BVR warfare.

Variants presented:

Pilot: Armour stripped down. Helmet replaced with a variant that can easily connect to spacecraft life support systems, has a clearer view, less protection and a more advanced HUD system that can read eye movement for controls.

Up-armoured: Heavier, adding a faceplate on the visor (With redundant cameras and an internal projector for vision, removable if damaged), reinforced alloys in some locations, shoulder pauldrons and applying the ST fluid layer in more areas, hindering movement slightly. On paper, a soldier clad in this can survive anything short of an anti-materiel rifle round. In practice, that claim isn't as solid, but this configuration gives an edge in CQB nonetheless. It is an unpopular variant due to extra mechanical complexity and reliance on the cameras built into the visor cover. Due to the added mass of the armour sections, many users wear a compact exoskeleton under the pressure layer (Under as it's isolated from the elements therefore less failure-prone).

Author's notes: Yes, the pilot helmet is inspired by the F-35 HMDS :) I'm sorry if the human anatomy is imperfect. My goal was to present the general details of the suit. I might post specific modified variants in the future. Sorry if my sentence structure is subpar, English isn't my first language.