Submarine launched UAV

By Jefferson Morris/Aerospace Daily

06-Aug-2002 9:41 AM U.S. EDT

The most likely method for the submarine of the future to launch unmanned aerial vehicles (UAVs) will be via capsules that float to the surface, according to Naval Undersea Warfare Center (NUWC) commander Rear Adm. John Butler.

Two industry teams are developing two similar torpedo-shaped capsules – the Stealthy Affordable Capsule System (SACS) and the Broaching Universal Buoyant Launcher (BUBL) – that float to the surface after being released from the sub and bob upright with their tips above the water. The tip of each capsule is then blown off to allow the deployment of UAVs or other systems.

BUBL and SACS “are the two concepts we’re looking at for UAVs as the most viable,” Butler told The DAILY. One of the selling points of the capsule method is that it introduces the UAV directly to the air, he said.

“The hardest thing about a submarine launch is the transition from the water interface to the air interface, and both SACS and BUBL take that away,” he said.

SACS and BUBL are the work of two industry teams that are studying sensor and payload concepts for future subs. Northrop Grumman is the lead contractor for SACS, which would have to be housed within a torpedo tube or missile tube, due to pressure constraints.

BUBL, on the other hand, “is good to test depth, so that you don’t have to have a hard structure around it,” Butler said. “You can mount it [on the sub] in whatever scheme you want.”

Other methods the Navy has studied for UAV deployment from subs include launch via the Universal Modular Mast (DAILY, May 23), the three-inch signal ejector, the trash disposal unit (TDU), or six-inch countermeasure launchers.

A demonstration of a UAV launch via BUBL or SACS could occur as early as 2004, according to Butler.

Because the Navy doesn’t want to develop new UAV systems specifically for submarines, the service is considering a number of existing small UAV systems to fulfill its needs, including AeroVironment’s X-Wing, The Insitu Group’s Seascan, Draper Laboratory’s Wide Area Surveillance Projectile (WASP), and the Air Force’s Miniature Air-Launched Decoy (MALD).

Although the Navy has experimented with submarine control of UAVs, in certain types of missions having the capability to deploy UAVs directly from the sub is desirable, Butler said.

“If there’s only a submarine there, [and] you’re in a week ahead of the battle group, it’s inherently important,” he said. “If you have a carrier or if you have an Air Force asset in the air that can drop one … then it’s not as important. So it’s strictly mission-dependent.”

These UAVs will be expendable, he said, because no practical method exists for the sub to easily recover them without losing its stealth. Rather than a single all-purpose platform, Butler expects the Navy will use a family of pre-existing UAVs.

Encapsulation systems such as BUBL and SACS will be a critical part of future submarine operations, Butler said, as they allow them to carry a variety of weapons developed by other services without having to reconfigure the submarines each time.

“I want to be able to take everybody’s weapon, anybody’s weapon, encapsulate it, and be able to shoot it from a submarine,” Butler said. “I don’t want to develop any more submarine-unique weapons. If I’m developing them just for me, it’s not affordable.”

Weapons being studied for encapsulation include the Army Tactical Missile System (TACMS). In addition to reducing production costs for the Army and acquisition costs for the Navy, encapsulating TACMS “lets me put a ballistic weapon [on the sub] … so I can do time-critical strike,” Butler said. “It lets me have a weapon on target in five to eight minutes.”

NUWC is the Navy’s research, development, test and evaluation, engineering and fleet support center for submarines, autonomous underwater systems, and offensive and defensive weapons systems associated with undersea warfare.