What is TARS?

A Tethered Aerostat Radar System (TARS) is a large fabric balloon that contains radar equipment and is used to carry out surveillance activities at high altitudes. The aerostat is a large fabric envelop which is filled with helium (looks like a big balloon) that can rise to an altitude of 15,000 feet. The radar equipment is housed inside the tethered aerostat, which can be raised and lowered by a tether to adjust to weather conditions and for maintenance.

TARS is operated by U.S. Customs and Border Protection and is equipped with an array of high-powered surveillance and communications equipment. Using tethered aerostats, TARS operators can relay essential data to the DHS (U.S. Department of Homeland Security) that is used to closely monitor border activity. This tethered aerostat radar system delivers continuous, long-term monitoring and detection (radar surveillance) capability for prohibiting low-level air, maritime and surface smugglers, and narcotics traffickers along the United States-Mexican border, the Florida Straits, and a portion of the Caribbean.

The Aerostat of the TARS system is made up of four major parts or assemblies:

• Hull: The hull of the aerostat contains two parts separated by a tight fabric partition. The upper chamber is filled with helium and provides the aerostat with lifting capability, while the lower chamber is a pressurized air compartment which is known as a ballonet. A sophisticated subsystem maintains constant pressurization of the ballonet, that maintains the shape of the aerostat's hull at all altitudes. The fabric of the hull provides resistance against environmental degradation, minimizes helium leakage, and provides structural strength to the aerostat. 
• Windscreen: The windscreen compartment of the aerostat contains the radar and is pressurized by the ballonet. 
• Power Generator: In some aerostat, the airborne power generator consists of an airborne engine control unit that drives the generator, and a 100-gallon fuel tank. Other systems use a power tether. 
• Rigging: Finally, the rigging consists of the flying suspension lines connected to the main tether and mooring suspension lines.

The TARS (Tethered Aerostat Radar System) provides surveillance data to the customs and border protection (CBP) office of air and marine (OAM) operation center (AMOC) in California and the Caribbean. Its operational locations are in Arizona, New Mexico, Texas, the Florida Keys, and Puerto Rico with support locations in Newport News, Virginia, and El Paso, Texas.