The U.S. Army is building twelve prototypes of its futuristic Land Warrior equipment system for infantry troops. The major components of the Land Warrior equipment set include a PDA (Personal Digital Assistant, like Palm Pilot) type computer system, GPS, personal radio, back mounted water (hydration) system, helmet mounted display, software and cable and wireless connections to make it all work together, as well as with sights on the soldiers rifle. Some of these systems are already in use, in one form or another. But these new prototypes will use available technology to push the futuristic concept as far as possible. Some items are pretty familiar to most people. These include GPS, PDAs, personal radios (sort of a hands free cell phone). Other items, while available on the open market, are less widely used. The principal item here is the helmet mounted display, a small display that can be flipped down over one eye. The display can show a map, text information, or video from a weapon sight (making it possible to point the weapon around a corner to see if its safe to proceed) or night vision camera. What the army is most interested in is how best to get all this stuff to work together. This means well designed software, and designing the physical shape of the different items so that they will survive the battlefield and continue to operate effectively. This can only be done by putting it all together on a bunch of soldiers, and then running them through some of the drills and exercises that prepare them for combat. Even if all the layout and software problems are solved, there is still the issue of battery life. The army is hoping that more powerful batteries, and electronics that need less juice, will soon solve the battery problem. Other solutions, of course, include keeping the equipment off most of the time. That is already being done. Even in combat, not everyone has all their electronic gear going all the time. Batteries are becoming like ammo. You cant fight without it, and often have to conserve it.