Building on work initiated in 1996, SEA CORP has explored the use of commercial automotive airbag inflators as a source of energy for launching special purpose payloads in air and water. The inflators have many advantages as a source of impulse energy; they are inexpensive, environmentally friendly, non-explosive, 99.9999% reliable and have a shelf-life of more than fifteen years.
The earliest stages of SEA CORP’s research and development were designed to prove that the inflators, originally designed to inflate a zero-mass balloon (the airbag), could effectively propel a projectile from a launch tube at desired acceleration and velocities. This was first proven in a series of three test launches of a six-inch diameter projectile in March 1996. This demonstration successfully completed Phase I of a Small Business Innovation Research (SBIR) Project.
With the unqualified success of Phase I, the Company was awarded a Phase II contract to scale-up the results to launch torpedoes weighing as much as 760 pounds and to demonstrate that the launches could be controlled to provide specified and selectable acceleration and velocity. Models were developed to simulate and analyze various combinations of inflators, timing and payloads. Eight test launches in 1997 and 1998 used actual surface vessel torpedo tubes and various types of dummy and exercise torpedoes, in some cases also using actual shipboard fire-control systems. These tests were also fully successful and validated the concept for use aboard Navy ships.
Based on the success of the Phase II Project, the Navy awarded an SBIR Phase III development contract to SEA CORP in 2000 to fully explore the feasibility of installing the improved launchers (in several versions) on surface combatants. An additional ten launches were conducted in 2002 to further refine launch parameters and to test specific components for actual shipboard systems. This program continued with additional funding provided in FY 2003 to complete engineering development and qualify the torpedo launcher for service use.
During the spring of 2004 SEA CORP installed and tested the Advanced Surface Launcher (ASL) aboard the Martha’s Vineyard High Speed Ferry “MILLENNIUM”. This test was an unqualified success conducting 31 launches of torpedo and countermeasure shapes over a five day period, at speeds up to 35 knots. Late in 2004 and into early 2005 SEA CORP designed and built the mounting system and tested the launcher on board an 11 meter Rigid Hull Inflatable Boat (RHIB). This test was also highly successful with nine torpedo shapes and three countermeasure shapes launched.
In 2001, SEA CORP performed an Internal Research and Development (IRAD) project to explore the use of inflators as a means for launching smaller shipboard countermeasures and decoys. This project, the Surface Combatant Auxiliary Launcher (SCAL), funded and executed entirely by SEA CORP, designed, built and test-fired a nominal four inch diameter launcher to approximate the launch characteristics of future anti-torpedo decoy programs. The SCAL project is especially pertinent because of the similarity of the projectile to a sonobuoy. Fifteen successful launches were conducted, again with no failures. In 2002, SEA CORP was awarded U.S. Patent 6,418,870 for an improved “Torpedo Launch Mechanism and Method.”
Airborne Gas Inflator Lightweight Ejector (AGILE)
The Airborne Gas Inflator Lightweight Ejector (AGILE) sonobuoy launcher was designed to use commercial-off-the-shelf (COTS) automotive airbag inflators to provide the impulse energy to eject the sonobuoys from Sikorsky’s MH-60R Seahawk helicopter. The system was designed to wholly eliminate the high pressure pneumatic system on the legacy launcher. AGILE’s modular design, capable of holding one to five horizontal trays, each with up to five preloaded sonobuoys or other munitions. The AGILE sonobuoy launcher was also designed to electronically interface with the legacy Interface Unit Automatic Data Processing (IUADP), sometimes referred to as the Programmable Interface Unit (PIU), even eliminating the need for some IUADP signals. Any necessary modifications to the IUADP were transparent to the sonobuoy launcher operator. Toward the end of the period of performance for Phase II of this SBIR effort with NAVAIR, eight launch tests were completed using twenty-seven pound AN/SSQ-77 sonobuoy s. The prototype system met the required exit velocities (31-40 ft/s for payloads in the 10-40 pound range). Despite successful design, development and testing that achieved all objectives, meeting requirements and proving the viability of an inflator-based sonobuoy launch system, the Navy made the determination to retain the legacy HP air launching system for use in MH-60R helicopters.
Energy Adaptive Gas Launch & Eject System (EAGLES)
The Energy Adaptive Gas Launch & Eject System (EAGLES) program was a proof-of-concept effort to demonstrate that commercial-off-the-shelf (COTS) automotive airbag inflators, or a modified version of the inflator, can be successfully used to eject a missile from a submerged submarine. During December 2014, SEA CORP successfully conducted testing of their EAGLES prototype at NSWC-Crane, IN. The sub-scale ejector system was designed, built, and tested to validate SEA CORP ballistic model predictions for a notional underwater missile ejector system. For this sub-scale prototype version, the launch tube was 19” in diameter and 10’ long with a payload (missile shape) that was 1000lbs. The ejector system used multiple COTS automotive airbag inflators precisely controlled for ignition by an electronics module; thus creating an optimum pressure curve for the entire stroke of the missile ejection process. The ejector can handle up to 64 inflators and launch payloads over 4000lbs, but for this testing only six inflators were required to achieve these results. SEA CORP engineers chose appropriate inflators from the automotive industry and designed the entire ejector and associated electronics to meet customer specifications for a sub-scale ejector design. The system was first tested with a land based firing and then moved to an underwater posture with a muzzle depth of approximately 13 feet. The 1000lb payload was ejected at ~85 ft/sec to an altitude of ~80’ above the water which was solid validation for thethereby soundly validating SEA CORP model predictions. Winter weather halted further testing which is now scheduled to resume in the April 2015 timeframe.