By Geoff Fein
The Navy has been able to demonstrate that a missile, such as the AIM-9X, can be deployed from a moving undersea platform, furthering the potential for use of similar submarine launched weapons against aircraft and small boats, according to a Navy official.
The Water Piercing Missile Launcher (WPML) program focuses on how the Navy can build a system that allows a submarine to launch weapons like AIM-9X, in particular, how the missile is packaged to create a jet in the water column to allow the missile to get through the water column safely and then transition to flight, Cmdr. John Vlattas, program manager advanced submarine systems development, told Defense Daily recently.
"The underlying requirement is for a missile that can engage low-flying aircraft, helicopters, and small craft," he said. "We are also looking down the road–are there other missile systems, things like SM-3, that could leverage this technology as we look at SSGN missile tubes and Virginia multi mission tubes, to be utilized without having to build a brand new missile?"
Until last month, the effort has been demonstrating the ability to launch a non-marinized missile from underwater. Those tank tests took place at Naval Surface Warfare Center (NSWC) Crane, Ind., Vlattas noted.
"We went from tank tests to basically fixed assets on the bottom of Lake Glendora, where we did it at varying depths," he said.
The Lake Glendora Testing Facility is located at NSWC Crane.
In early May, Naval Sea Systems Command SEA 073R started looking at moving the test platform to simulate what it would be like to launch an AIM-9X from a submarine and to examine the impacts of motion on the missile, Vlattas added. "That’s probably the largest technical hurdle the folks down at (NSWC) Dahlgren faced."
Dahlgren is a partner on the test program.
"What we found was when you started translating the launch platform and you try to create this jet from the missile to fly through, obviously with the cross flow across the surface, the jet changes and you find the missile might have to fly through some water," Vlattas said.
"What we tried to do over the last probably year to two years culminating in this last test, was validate how the cross flow affects the jet," he added. "We got up to speeds of a little over five knots. Then because we have seen the jet move and [seen that] the missile is going to have to fly through an air-water interface, we validated that. It’s a steady progression to validate things that are more closely approximating launch from a submarine platform."
Vlattas’ team has conducted 17 tests in a static gas column and then about 18 tests at three knots to begin simulating a moving submarine. "It’s been a significant data set, so that we could really build these computational data models," he said.
Now instead of having to conduct actual tests, SEA 073R personnel can validate results using computer modeling and simulation, Vlattas said. "We still have to take a look at some additional areas."
For example, right now the missile launcher itself is a stand alone system, Vlattas said. "What happens when you want to interface that missile system with the onboard submarine architecture, our submarine warfare federate tactical system, our BYG-1 fire control? How does the periscope get input to maybe give some type of information to the missile on where to look?
"That’s going to be a technical challenge–how you begin to take a look at the stand alone design and how do you fit it in," he added. "Some additional work needs to be done to further validate this for submarine platforms. We don’t always go five knots, we don’t always go at 30 feet, so we have to really finish validating the computer model to allow us to extrapolate to higher speeds."
If those models check out, the Navy could potentially do some more testing at somewhere such as San Clemente Island, Calif., or potentially down the road on a submarine itself, Vlattas said.
"My estimate is that it’s a three- to five-year systems development phase that takes this basic work we have done in WPML and translates it," he said. "I am comfortable with what I am giving to PMS 415 (Undersea Defensive Warfare Systems Program Office) right now. They have the tools to further go and validate that technology and get this thing installed on submarines."
Vlattas’ office has been the program manager for not only WPML but for the Littoral Warfare Weapon (LWW) too.
"We have done the program management for the actual experimentation work for LWW and WPML, so from the standpoint of executing these tests and getting things under contract and doing program reviews, that’s us. My people have done a great job in getting us to this point," Vlattas said.
The LWW portion was more focused on how an AIM-9X goes through the water column, he added.
Those demonstrations focused on things like how does the missile transition in flight, how does it focus in, what has to be done to the missile to change it from the standpoint of being deployed from an airplane where it is deployed from a platform moving at 500 mph and horizontally positioned to a platform that is moving at essentially zero and firing from a vertical standpoint.
In July ’09, the LWW team was able to prove that a missile could be launched from a submerged tube, go up into the air and fly (Defense Daily, Sept. 15).