The Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System, or JLENS (colloquially, Spy Balloon), is a tethered aerial detection system designed to track boats, ground vehicles, cruise missiles, manned and unmanned aircraft (airborne early warning and control), and other threats. The system has four primary components: two tethered aerostats which utilize a helium/air mix, armored mooring stations, sophisticated radars, and a processing station designed to communicate with anti-missile and other ground and airborne systems. Each system is referred to as an "orbit", and two orbits have been built. The Army-led joint program is designed to complement fixed-wing surveillance aircraft, saving money on crew, fuel, maintenance and other costs, and give military commanders advance