I don't buy into all that is said in this article, and some of it is, well, let's just say underinformed - but it is a good conversation starter. Let's review.
1. Antiship Mines: Even technologically crude sea mines can slow down a superior Navy, especially if the explosives are laid in shallow water or a port area. (For proof, ask the U.S. navy how much fun it was to clear the Iraqi port at Umm Qasr.) Since acoustics are still the primary way warships find mines, advanced sonar is being researched for use on robotic systems that can report the locations of mines well before the fleet gets close. ONR is looking at using low-frequency broadband technology that returns strong echoes despite reverberations in shallow water. That tech will be combined with small synthetic aperture sonar, which combines numerous acoustic "pings" to form a high-resolution image of what's hidden below. This gear will be instilled in a long-range underwater droid that looks like a torpedo and will be capable of finding mines amid the clutter of harbors, the busy noise of ports and the muck of rivers.What is our report card today on these Top 5 threats? Well; F, D, D-, C, B.
2. Rust: Life at sea is hard on even the toughest ships. Corrosion damage to ships is hard on budgets and deployment timetables, too. As proof of the constant worry, the Navy operates a Marine Corrosion Facility near Key West, Fla., that uses a deep channel in the ocean as a natural seawater test site. Using data and test grounds at this well-placed research center, the ONR sees the future of rust prevention in sensors embedded in the ship's materials that can warn maintenance crews of damage, especially unseen parts of the hull, before it can spread. The Navy is also pursuing research in the use of new, rust-resistant treatments and materials.
3. Ballistic Missiles: Navy aircraft carriers are the leading edge of U.S power projection, and as such are popular targets for new weapons systems built by China and Russia. Today's cruise missiles are bad enough, but ballistic ship-killers are on the way. These can be launched from far away, descend at high velocities from directly above a ship and carry large warheads. "China envisions an attack on a carrier strike group as incorporating submarine-launched antiship cruise missile strikes and antiship ballistic missile strikes," states a U.S. naval intelligence report made public in March 2007. Experts have chimed in that the satellite connections required to guide such a missile to a moving target may not be possible for China to field until 2010. Variants of their DF-21 family of missiles will make an old standby ballistic missile into a ship-killer. The ONR is working on hardkill defenses—military jargon for defensive missiles hitting incoming missiles, rather than spoofing them with chaff or avionic-scrambling lasers—that include ballistic threats. The scope of the Navy's detection and countermeasures will also be a research focus: It takes a fleet to defend a carrier, and fusing data from aircraft, ships and ground radar stations is needed.
4. Swarming Attacks: Small ships can only damage a well-equipped Navy if many of them attack at once. A number of explosive-laden suicide craft in a tight waterway such as the Straight of Hormuz could be remarkably effective. Nor surprisingly, the U.S. Navy is very interested in improving its ability to track multiple targets. Since aircraft are among a ship's first, best defenses, the ONR is focusing research on giving helicopters and airplanes the optics to track and fire on numerous targets at once. Instead of multiple laser nodes tracking each target, the Navy is pushing the idea of quickly flickering one laser beam to designate targets for precision weapons systems. An ideal system would share this targeting information with onboard commanders so that those in charge have a better idea of what to shoot and when. The system would be used against ground targets as well.
5. Causing Collateral Casualties: When the Navy is supporting ground troops, especially in urban areas, the last thing a pilot wants to do is turn down a request for help because the only bombs on board the warplane are too big to use. The Navy's solution is a "Selectable Output Weapon" that allows pilots to choose the bomb's desired blast size and fragmentation level from the cockpit. The utility weapon will likely be made of composite material and built using the body of a standard 500-pound bomb. Aside from reducing collateral damage, such a system would reduce costs by eliminating specialty weapons from the arsenal.
UPDATE: Two very good posts from SJS on the ASBM issue here and here.