The recent retirement of the U.S. Navy's S-3 "Viking" anti-submarine aircraft was interrupted when it was realized that four of these S-3s could be used to replace P-3 and C-130 aircraft used to patrol the Pacific missile test range in Hawaii. This instrumented (it's got lots of sensors to monitor what happens when weapons are launched) is in Hawaii, and contains 109,000 square kilometers of airspace that has to be patrolled, before a test, to make sure no ships have wandered into the area. The jet propelled S-3, which normally operates on carriers, is faster than the propeller driven P-3s and C-130s that have long done the patrol work.
Better yet, Three years ago, the navy took advantage of new, lightweight, search radars and targeting pods and began equipping S-3 aircraft with Lantirn targeting pods. This was in an effort to extend the life of the S-3s, as reconnaissance aircraft. The S-3 was originally designed as an anti-submarine aircraft, and served in that capacity from its introduction in the mid 1970s, to the late 1990s.
The end of the Cold War ended most of the submarine threat, and since 1999, the S-3 has served as a patrol aircraft, and aerial tanker. But it was hoped that a reequipped S-3, with the long range (ten hours per sortie), day/night video capability of the Lantirn, and lightweight search radar, would make it a much more effective maritime patrol aircraft. The Lantirn pod costs two million dollars, and is hung off a hard point like a bomb or fuel tank.
The search radar, that can spot ships fifty or more kilometers away, enables an S-3 to quickly scan a huge chunk of ocean in a few hours. But the key element here is the targeting pod, which eliminates the need to fly down low to visually confirm what the ship (that is easily spotted by the radar) is. With the targeting pod, you can stay high (20,000 feet) and far away (over twenty kilometers) and still get a close look. The S-3 can also carried Harpoon anti-ship missiles, in case the ship below is hostile.
For patrolling the missile test range, missiles are not needed. But the Lantrin comes in very handy, as the ships most likely to stray into the area are smaller ones, often pleasure craft. The S-3 radar and sensors can spot these small craft, while moving along at high speed and high altitude. Four S-3Bs will be assigned to the Pacific missile test range, while the rest will go to the "boneyard" for storage and, eventually, disassembly for parts and scrap.