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BOSCH Aerospace is the developer, operator, and manufacturer of a series of unmanned surveillance airships known as SASS LITE (Small Airship Surveillance System, Low Intensity Target Exploitation). These airships (under development and in operations since 1988) were designed to provide long endurance surveillance and reconnaissance in a wide range of military operational areas. SASS LITE has been used for border surveillance, waterway surveillance, search and rescue, instrumentation for missile data collection, and radio relay operations. SASS LITE takes advantage of the many years of blimp experience gained by the US military since the early 1900's. The design goals specifically called for reduction in blimp systems cost, crew size, and training versus the manned blimps which were phased out of the US Military in the 1960's. The development met each of these goals and more. RADIO CONTROL SYSTEM: SASS LITE is equipped with a triple redundancy radio control system. Its primary control link is in the "L" band microwave frequencies. An autotrack dish antenna is used to provide direct control to 100 kilometers. Video downlink is also accomplished in this frequency range. The "L" band data links are backed-up with a function matched "P" band data link system which is equipped with Yaggi directional antennas. These systems are interfaced to a digital autopilot and GPS navigator which facilitates autonomous navigation beyond radio line of sight. An independent, battery powered, multi-function Flight Termination System (FTS)is carried on the nose ring of the airship. This FTS system allows for engine shutdown, ballast, and helium vent control, and includes a hot wire burn system, The shutdown and vent control features allow for "FREE BALLOON" operations to a desirable landing site, while the burn wire can be activated to destroy the ship inflight if mandated by military necessity. Electronics are jam resistant and the primary system is military hardened. Control servos are high grade commercial items chosen for their durability and proven life cycles. The tail servos are similar to the rotary servos used by Goodyear. The servos are connected to the RF link via hard wire and MILSPEC Cannon connectors. Extensive water proofing and forced air cooling is used to maintain strong heat extraction from electronic bays. All electronics are located in impact resistant compartments on the envelope or power car. An advanced digital switching and telemetry system allows the ground operators to control all airship functions, and the payload. Three 9600 baud digital links are embedded in the data link system to facilitate control of the many tens of functions needed in a sophisticated airship. Automated control devices such as pressure control, vents, and auto-navigation can be instantly over-riden by the pilot through the digital link structure. PAYLOADS: SASS LITE can be equipped with a variety of sensors, radio relays, scientific instruments, or Electronic Warfare devices. Its payload attaching system facilitates fast changeout of payloads, and installation of a wide range of payload shapes, volumes, and weights. The current airship carries loads of approximately 400 lb (190 Kg) and it is capable of greater loads with reduced fuel loads. SASS LITE has carried multiple Infrared and visible cameras on independent gimbals on a single mission, as well as a combination multi-spectral payload that included radar, IR, and Visible light sensors interfaced via a software bridge. Power for payloads is provided by two onboard alternators delivering a total of 3250 watts at 24 VDC. SIZE and PERFORMANCE: A variety of SASS LITE versions have been built. They ships manufactured to date include the following envelope sizes: Ship Number 001 & 002: 12,000 ft3 volume, 60X20 feet-Single 42 hpShip Number 003: 17,000 ft3 volume, 72X21 feet-Single 42 hpShip Number 004: 22,000 ft3 volume, 82X22 feet-Single 42 hpShip Number 005: 30,000 ft3 volume, 92X25 feet-Dual EngineShip Number 006: 34,500 ft3 volume, 100X25 feet-Dual EngineThe airships operate in speed ranges to 45 mph maximum.