Tactical Aerobotic Launch System (TALS), 15-R8226
William D. Perry
Michael L. Fortenberry
Inclusive Dates: 04/18/11 – 02/29/12
Background — The process for inflating and launching typical LTA (lighter-than-air) systems presently requires a large paved or grassy area that is clear of obstructions, where the hull can be unpacked and laid out length-wise in preparation for inflation. This process often can take 12 or more people to accomplish. This process often must be conducted inside a very large hangar or outdoors under very low wind conditions because these hulls can be several hundred feet in length and made from very lightweight material. It often requires large handling equipment along with an experienced launch team to get it launched without damage. Most military applications would prefer to deploy LTA systems quickly from remote unimproved sites with minimum personnel in less than optimal meteorological ground conditions. Using current launch processes, that is presently not possible.
This project investigated a concept for rapidly launching LTA systems from a self-contained package that provides inflation, stabilization, protection and finally release. TALS could be operated by a small team or autonomously to launch a LTA system on command. SwRI has been conducting a spiral development of the HiSentinel stratospheric airships for several years. These prototype airships have been manually launched, a process requiring very low surface winds, and a large team to get the airship inflated and launched. SwRI's DOD clients have indicated a quick and easy way to deploy these LTA systems is needed. TALS could greatly improve the versatility and utility of the airship, and other LTA systems, allowing them to be used in a wider variety of tactical applications.
Approach — The TALS concept uses a single shipping container in which the LTA system is packed along with a supply of lifting gas (helium or hydrogen). The inflation subsystem includes batteries for power and a digital electronics system that controls the inflation and launch process. The TALS container will be transported to the launch site by truck or helicopter, where the container is secured to the ground, vehicle, or other structure. Once the container is secured, the LTA system can be launched or it can be left to be autonomously launched at a later time by either a timer or telecommand. After launch, the container housing the inflation system and launch controls can be recovered and refurbished for reuse.
At the planned launch time, the integrated control system will determine if the wind velocity and direction are acceptable. If acceptable, the inflation and launch process will begin with the top of the container opening to expose the protective tent that covers the folded LTA system. Guy lines attached to the tent with automated tensioning will provide stability during the inflation process. Inflation rate and total gas quantity will automatically be controlled. The hull will rise from the container as it is inflated inside a protective tent. When the predetermined amount of lifting gas has been injected, the gas flow will cease and the top of the tent will open, allowing the LTA vehicle to escape and ascend. Once released and ascending, the hull will unfold until it is fully extended.
Accomplishments — Phase 1: The team successfully conducted a feasibility study for the TALS concept. The study included four primary tasks:
- Performance Requirements for a full-scale TALS System
- Preliminary design for a full-scale TALS System
- Feasibility Analysis
- Detail design for a functional 35-percent scale model of TALS.
Based on the results of these tasks, it was determined that the proposed go/no-go criteria had been met and Phase 2 was authorized.
Phase 2: A functional 35-percent scale model of the TALS was fabricated and integrated. Subsystems for the TALS demonstrator were each independently tested in the laboratory. The completed TALS prototype was integrated, and functional tests were conducted. The illustration shows a TALS launch sequence during a field test of the demonstration prototype. Based on these tests, the team has shown the feasibility of the TALS concept.