Everyone knows U.S. Army infantry soldiers look intense—dressed in uniform and packing enough gear to take on a small nation.

Drawings of the gear – some parts already in prototype and in the field – look like futuristic “Master Chief,” the human über-soldier who battles aliens in the popular sci-fi video game Halo.

An curved arrow pointing right. An instructor at the US Army Mountain Warfare School breaks down every piece of gear a mountain soldier would carry on a cold-weather mission, including tactical ...