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Ultra-Endurance UAV



OBJECTIVE: Produce a low cost, ultra-long endurance (>7 day) Unmanned Air Vehicle (UAV) suitable for intelligence, surveillance and reconnaissance (ISR) missions. 

DESCRIPTION: Unmanned air vehicles play an important role in todays military operations. They are invaluable in locating time critical targets, reporting enemy positions and movements to battlefield commanders, and destroying tactical targets. One important aspect of these operations is the ability to provide persistence in monitoring an area of interest. Most of the current UAVs are designed to remain in flight for time periods of 20-40 hours, primarily limited by fuel capacity. This creates a deployment and logistics challenge for battlefield commanders to maintain eyes on target for extended periods of time, which is usually achieved by deploying multiple waves of UAVs. The objective of this topic is to develop a low cost UAV with very long endurance, of at least seven days, that would enable the ISR mission to be accomplished with reduced manpower and system resources (esp. number of vehicles) to maintain near continuous coverage. Operating footprint should minimize personnel and hardware as compared to other UAV systems. Notionally the UAV will transit from its launch point to the area of interest nominally several hundred miles away, and loiter in that region for the mission duration, although the ability to move quickly between nearby areas of interest is also desired. The UAV should provide the capability to fly at 10,000-15,000 feet AGL, with a payload of 250lbs and 2000W power requirement. The system must be able to operate in 50 knot winds aloft, with minimal degradation in range and endurance or deviation from the area of interest. The system must also demonstrate minimal acoustic and visual signature to be virtually undetectable by ground personnel. The system must also be able to transit light to moderate icing conditions associated with climbing and descending through stratus cloud layers containing known icing conditions. The system does not need to loiter for prolonged periods in icing conditions. Typical take-off profiles are constant slope and minimum altitude changes are required once on profile. A number of possible technologies can be considered to meet this requirement, but it is anticipated that the most likely candidates include hybrid power systems, solar power, and possibly power harvesting. Other technologies such as conventional airships (may not meet winds aloft requirement), laser power transmission (difficult to provide laser transmission to remote areas of interest), and tethered aircraft (no flexibility to move to remote areas) may not be suitable unless innovative approaches can be developed to overcome their limitations for the envisioned missions. Some key desired capabilities of the system are: Allow for >7 day vehicle endurance capabilities Support payloads of 250lbs while supplying 2000W Transit from launch location to area of interest up to several thousand miles and return safely Maintain ˜orbit over area of interest in most weather conditions, but primarily winds aloft of up to 50 knots and intermittent light to moderate icing conditions Acoustic and visual signature should be virtually undetectable by unaided ground personnel Operate on logistically available fuels (diesel, Jet-A, Mo-Gas, etc.) Suitable for military operational environments, including typical site constraints and runway sizes in Forward Operating Bases (FOB) Minimal maintenance required in comparison to typical UAVs Minimum personnel and hardware footprint as compared to other UAS System cost to include the UAV, Broadband SATCOM, launch/recovery system (if any), fueling system (if unique), etc. < $1M 

PHASE I: The contractor shall provide trade studiesand engineering design necessary to define the operational system & associated technologies. The contractor shall show evidence that key enabling technologies are adequately mature (e.g., Technology Readiness Level >=6). Key enabling technologies shall include propulsion system, electrical power generation, flight control adequate to control necessary endurance parameters, energy storage, & anti-icing systems if required. 

PHASE II: The contractor shall develop and test a UAV that provides the capability to loiter over an area of interest for >7 days. The test program shall culminate in a demonstration, on a government test range, of >7 days endurance at representative altitudes, carrying payload and mass simulators totaling 250 lbs. 

PHASE III: The various technologies developed in Phase II are applicable to military and government applications. There are potential commercial applications in a wide range of diverse fields that include airborne communication nodes for cellular communications, crop monitoring, and site security. 


1.Effect of power system technology and mission requirements on high altitude long endurance aircraft, Colozza, Anthony J. NASA Report Number NASA-CR-194455, 1994.

2.Low Reynolds number, long endurance aircraft design, Foch, R. & Ailinger, K. AIAA, Aerospace Design Conference, Irvine, CA, 3-6 February 1992.

3.High Altitude Long Endurance Air Vehicle Analysis of Alternatives and Technology Requirements Development Craig L. Nickol and Mark D. Guynn and Lisa L. Kohout, Thomas A. Ozoroski, 45th AIAA Aerospace Sciences Meeting, Reno, NV, 8-11 Jan. 2007.


KEYWORDS: Long Endurance Air Vehicle, Unmanned Aerial System, UAV, Airborne Surveillance, Persistent Intelligence Surveillance And Reconnaissance 

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