JLENS, the US Army surveillance system that has recently completed a functional review, is mostly known for its comically truncated acronym, which stands for (deep breath): Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System. (Exhale)
Basically, it's a very large balloon tethered to the ground carrying a 7,000 pound radar -- a derivative of the Lockheed Martin SPY-1 found in Aegis combat system-equipped destroyers and cruisers. As its clunky name suggests, JLENS is supposed to do one of the hardest jobs on the battlefield: spot slow, low-flying and sometimes stealthy cruise missiles flying in the general direction of friendly forces.
I know JLENS for another distinguishing characteristic: its price tag.
What do you think it would cost to buy a tethered balloon (okay, call it an aerostat), a radar, a ground station and a fiber-optic cable?
The answer: $391 million, according to the Government Accountability Office. To put it in perspective, this aerostat-plus-radar costs almost more than one F-22.