Navy plans point to role for sub-rosa radar
Maritime missiles are in a period of rapid evolution. Warships and submarines are persistent platforms with deep magazines, for long-range attacks on land targets and hostile ships. But more warships now carry effective missile-defense gun and missile systems and countermeasures, while sea traffic has continued to grow rapidly worldwide—creating a major challenge in terms of collateral damage.
Some of the biggest decisions in the past year involve the U.S. Navy, which is moving toward an arsenal of “net-enabled” weapons—missiles that take advantage of other sensors to find and hit targets, but can still function if communications are down. Two quick-reaction missile programs have been started recently, along with a large, expensive and remarkably low-profile airborne radar to support them.
The use of a long-range, high-resolution airborne radar to help guide net-enabled missiles to targets is an important part of the Navy's concept. Publicized tests of this concept (in early 2011) used the U.S. Air Force's E-8C Joint Stars radar platform, but documents obtained by Aviation Week show the Navy has used its own P-3C-mounted APS-149 Littoral Surveillance Radar System (LSRS) in the same way.
Anti-surface warfare (ASuW) is a likely mission for the APS-149's successor, theAdvanced Airborne Sensor (AAS), which is now under full-scale development and will be carried by the . While AAS is not a black program as LSRS was in its early years, it is run by a separate office from other programs and there was no competition (or public analysis of alternatives) preceding development. Its importance can be judged by the fact that—as far back as 2003— drastically changed its proposed P-8A design to accommodate it, going to the longer-bodied platform and moving the weapons bay behind the wing.
Large radars like LSRS and AAS are important in the “net-enabled” concept because they provide more accurate identification, classification and location data than the shooter's radar, at greater range. They can provide the missile with targeting-quality updates and the location of non-target ships, while remaining outside the reach of shipboard anti-air-warfare missiles. The shooter can approach the target “cold nose” and at low level, fire and turn away.
AAS should enter service around 2016—about the same time as the Navy fields its first long-range, net-enabled ASuW weapon. In June, the Navy announced that it planned to award a sole-source contract to Raytheon to develop an interim Offensive Anti-Surface Weapon (OASuW) by modifying Tomahawk Block IV missiles with new sensors and data links, with a planned in-service date of 2015.
That weapon is one of a number of developments that emerged from an OASuW study last year. The Navy is pursuing two near-term net-enabled weapons. The unpowered Raytheon AGM-154C-1 Joint Stand-Off Weapon (JSOW) was part of the Joint SuW joint capabilities technology demonstration (JCTD) in 2010-11 (in captive mode) and underwent its first free-flight test in August 2011. It is due to be operational next year.
Boeing is developing the Block II Plus version of theHarpoon, which adds the AGM-154C-1's Strike Common Weapon Datalink to the missile, allowing it to receive in-flight updates. (The weapon could also be launched by the P-8A/AAS.) This should be operational in 2017.
The Navy is also looking at an air- or sea-launched weapon to replace the Harpoon and Standoff Land Attack Missile—Extended Range (SLAM-ER) in the maritime interdiction role. Candidates could include Raytheon's JSOW-Extended Range, fitted with a Hamilton Sundstrand TJ50 sustainer engine, or the Norwegian Kongsberg Joint Strike Missile (JSM), both of which could be carried internally on theJoint Strike Fighter. According to Navy documents, this weapon should start development with Milestone B approval in 2017 and would be operational “no later than 2024” to match Harpoon's retirement date.
The extended-range JSOW has the benefit of incumbency because it presents no significant integration challenge on aircraft that carry JSOW, including JSF, and has the same guidance system as the C-1 variant. Kongsberg argues that JSM's stealthier design and greater power—which makes it more agile and harder to hit—are advantages.
In another unpublicized development this year, the Navy and thequietly canceled the high-altitude, supersonic strand of the Long-Range Anti-Ship Missile project (Lrasm-B) in January. The surviving Lrasm-A uses the subsonic, stealthy airframe of the AGM-158A Joint Air-to-Surface Standoff Missile ( ).
The main thrusts of the Lrasm program are to demonstrate its multi-mode sensor suite (both the A and B versions used the same seeker technology, from) and to develop and test a vertical-launch, rocket-boosted version of Jassm. The sensor suite, which completed its first captive tests in July, comprises a radio-frequency seeker to detect targets, an electro-optical imager for target identification and precise targeting, and a weapon data link.
Full-up tests of an air-launched Lrasm test vehicle are planned for early 2013, followed by tests of a vertically launched variant in late 2014. In the long term, the Jassm-based system could compete against a Tomahawk derivative for a future multipurpose missile.
Europe is also moving forward with maritime missiles. On July 9 the French procurement agency DGA achieved a complete firing sequence of the MBDA MdCN (missile de croisiere naval), the future French naval cruise missile.
This test, the third for the MdCN, validated the terminal guidance system, with automatic infrared recognition of the scene that ensures a high-precision impact. The missile will be fielded next year on the French navy's Fremm frigate Normandie, using DCNS Sylver A70 vertical launchers. In 2017 it will be operational on the French navy's nuclear-powered Barracuda attack submarines.
Formerly known as Scalp Naval, the MdCN draws extensively from the architecture of the air-launched Storm Shadow/Scalp cruise missiles, which proved effective during the Libya campaign last year. However, the Storm Shadow/Scalp's Broach warhead has been replaced with a smaller multimode version, freeing up space for fuel and extending the weapon's range well beyond 1,000 km (620 mi.). The weapon has a different airframe to fit vertical launch and torpedo tubes.
The initial version of MdCN will not have a data link for inflight target updates, but has been designed so this can be added, together with the possible incorporation of Galileo satellite guidance, as well as GPS.
MBDA received the MdCN development and production contract for the weapon from French armaments agency DGA in 2006. Aerodynamic trials, general missile architecture, launch platform interfaces and mission planning were completed in 2008. The first A70 test firing was successfully carried out in May 2010 and the first submarine launch in June 2011.
The Italian navy looked at MdCN and Tomahawk Block IV for its Fremm ships, then decided to look at evolving MBDA's Italian-developed Teseo missile for anti-ship missions and “light strike” coastal and land-attack use. The goal is to keep the Teseo in service until 2040.
MBDA has carried out a modernization program to produce the Teseo Mk2A, which completed its qualification trials at the end of 2007. The Mk2A (known as Otomat Block IV for export) core consists of the digitization of the weapon and of its planning station.
With an advanced navigation system, including a secure GPS receiver and replacement of obsolete analog subsystems, the Mk2A is more survivable and lethal in its main anti-ship role, having acquired, for instance, the ability to conduct salvo attacks with missiles flying different profiles. It is also capable of engaging targets in the difficult coastal environment, adding a land navigation capability.
MBDA has carried out preliminary studies and is in contract with engine manufacturers for a more efficient and compact engine. Coupled with bigger fuel tanks (also a benefit of digitization because the new avionics are smaller and lighter), this could almost double the 100-nm range of today's missile, allowing engagement of targets well inside the coastline. The semi-armor-piercing blast warhead would enable it to attack a range of targets.
Another upgrade will involve replacement of the GPS with a more advancedunit, while the seeker could be replaced by a fully coherent active radar offering advanced modes, included synthetic aperture radar, to allow selection of impact point and target recognition. MBDA is considering the use of a semi-active laser seeker for high-precision land attacks, and a two-way data link would be incorporated. Aerodynamic modifications will exploit increased engine thrust. What will be retained will be extreme maneuverability and very-low-altitude, sea-skimming attack profile.
The company plans to leverage other missile programs, including an improved version of the Aspide surface-to-air missile and the Marte ER with technology cross-fertilization.
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