The Non-Line of Site Cannon (NLOS-C) is the highest priority vehicle/weapon program in the Army's Future Combat System (FCS). In a nutshell it is a lightweight 155mm howitzer mounted on a relatively small two person crew vehicle which has just been selected for further development. It will be a hybrid-electric vehicle.
Self-propelled howitzers are hardly Earth shattering technology in and of themselves. But, previous weapons systems of this type have been too big to airlift in large numbers. This system would be much smaller and lighter weight than either existing systems of this type or previously planned systems.
The pie in the sky technological advances and high costs ($200 billion) of the FCS in the face of pressure to fund more urgent missions has left the FCS program crumbling. The Army is hot to get, at least, a few lower risk, higher demand projects out of the FCS pit before it caves in on itself. The artillery specialty within the Army is also particularly hot to upgrade its weapons and make itself more relevant while it can, because current plans call for the Army to reduce artillery forces relative to other types of Army units that are in higher demand. The smaller the force, with the exception of special forces, the less clout it tends to have in budget discussions.
The NLOS-C, which will run 23 tons in a prototype with plans to slim that to under 19 tons so it can be transported on a C-130, is a priority because the Army already has an interim light weight HIMARS multiple rocket launcher based on a 5 ton truck chasis, and the roughly 20 ton Stryker mobile gun system, which provides a light tank like direct fire system. Other versions of the Stryker provide a light weight subsitute to the Bradley Infantry Fighting Vehicle.
But, the Army's most recent self-propelled howitzer system is the 30 ton Paladin (a 1993 upgrade of a 1963 M109 design), since its successor program, the 41 ton Crusader, was one cancelled in 2002 as one of the first decisive acts of Secretary of Defense Rumsfield in the current administration.
HIMARS, the Stryker, and the NLOS-C program are all part of the ongoing stuggle of the Army to develop versions of its main types of weapons systems that are C-130 intratheater cargo plane transportable. This would allow the Army to deploy medium weight weapons, rapidly, to air strips close to a battlefield, with a plane that the military has in great numbers.
None of these systems are designed to handle a full fledged conventional military attack by a large armored military unit of tanks, anti-armor weapons and close air support aircraft. But, these systems are designed to provide a powerful counterweight to opposition infantry units or light mechanized infantry forces that one might find in a third world or insurgent military force.
The prototypical mission of HIMARS is to lob a missile full of cluster bombs into a tight formation of or base for enemy infantry; as guidance systems become more accurate, it is also seen as a way to attack particular enemy buildings or vehicles from a distance. The prototypical mission of the Stryker MGS is to fire a 105mm round at enemy units behind a wall or in a building, in support of U.S. ground troops. The prototypical mission of the primary variant of the Stryker is to carry infantry to places where they might be shot at, along with some infantry support weapons. The prototypical mission of the NLOS-C would be to destroy an enemy machine gun nest or fuel depot or ammunition depot from a position of safety "over the hill" from opposing troops.
Currently, the Bradley based multiple rocket launch system, the M1 Abrahms tank and the Paladin howitzer can each be carried only on a larger intertheater C-5 or C-17 cargo plane. A C-5 can't land on field airstrips close to the battlefield, and there aren't many C-17s to go around. So, the Army must choose between the weeks it takes to deploy heavy forces by ship and rail and convoy, and the days it takes to deploy lightly equipped paratroopers aka "speed bumps" via air lift. But, when the opposition is only lightly armed, the relatively heavy armor provided by the heavier systems is overkill, while delay may put U.S. troops at a disadvantage.
The other priority is JITTERS, an integrated communications system.
Prioritizing, of course, means other systems are ranked as lower priorities in the FCS program. What are they?
A self-propelled mortar
A self-propelled multiple rocket launcher
An infantry carrier vehicle
A command and control vehicle
A field ambulance
A surveilance vehicle
A field tow truck
An armed unmanned ground vehicle
A small unmanned ground vehicle
A cargo carrying unmanned ground vehicle
Smart land mines
Remote ground based sensors
Four kinds of unmanned aerial vehicles (UAVs) from small to big.