Sunday, September 29, 2013

Laser Guided Rockets


Laser-Guided Rockets, at Long Last!

Recent operations have highlighted the fact that anti-armour guided weapons that were developed to meet the demands of a major European war are an unnecessarily expensive means to attack today’s counterinsurgency targets, typified by small groups of personnel or light vehicles. 
The high cost of weapons used (or misused) in Afghanistan from 2001 and Iraq from 2003 has caused serious concern, and so has the bad publicity associated with collateral damage and casualties. Weapons with undesirable side-effects have to be carefully restricted in use, consequently leaving many targets unscathed.
A lighter missile would reduce cost and collateral effects, and allow a helicopter to carry more guided weapons, achieving more soft target kills per sortie.
A further consideration has been the growing use of armed drones.  Weighing 45 kg, the Hellfire is sufficiently light to be carried by the US Air Force’s General Atomics’ 1157 kg MQ-1 Predator and 4763 kg MQ-9 Reaper, and the US Army’s 1633 kg MQ-1C Grey Eagle. However, an even lighter missile would allow the arming of small drones, operated in much larger numbers. 
In principle, arming lightweight drones would reduce response times, saving lives and engaging fleeting targets, and put close air support back in the warrior’s own hands.
There has thus for many years been a clear need for a missile to fill the wide gap between cheap unguided rocket projectiles such as the $ 2,000 70 mm General Dynamics Hydra-70 and costly antitank guided weapons like the $ 90,000 laser-homing Hellfire.
This gap-filler needs only a small warhead, but it must be delivered with metric precision.  It also needs sufficient range to minimise the risk of the launch aircraft receiving return fire from the target area.
One way to reduce the cost of the new system is to develop a bolt-on guidance and control kit for stockpiled rockets.  However, there may also be a substantial market for
a brand-new 70 mm LGR (laser-guided rocket), using a more powerful motor to offset the weight penalty of the guidance and control module, in combination with a modern warhead family.
The Texas Instruments Paveway LGB (laser-guided bomb) was first used operationally by the US Air Force McDonnell F-4E in Vietnam in April 1972.  The BAE Systems APKWS (Advanced Precision Kill Weapon System) LGR, a converted Hydra-70 rocket projectile, was first employed operationally in Afghanistan almost exactly 40 years later, in March 2012, from the US Marine Corps Bell AH-1W and UH-1Y.

I  Not Rocket Science
Why this advance should have taken four whole decades may partly be explained by the fact that only recently (post-September 2001) have we witnessed a return to colonial-style wars, in which the troublemaker lives next door to innocent civilians.  Another factor may have been that the two senior US services each hoped that the other would provide the funding for LGR development.
Industry may have felt deterred from private-venturing laser-guided rocket develop?ment, due to the high cost of clearing a new weapon for a specific helicopter, when the Pentagon was incapable of deciding which service and which helicopters would use it.
The APKWS programme was launched in 1996, when the Department of Army approved a Mission Need Statement (MNS), essentially for an affordable weapon for the Boeing AH-64 to use against soft and lightly armoured targets outside cannon range.  However, the Operational Requirement Document (ORD) was formally approved only in 2000.
In 1999 the service’s Aviation and Missile Command (Amcom) had requested industry proposals for an Advanced Technology Demonstration (ATD) programme designated LCPK GR (Low-Cost Precision Kill, Guided Rocket).  This was to provide the basis for the Directorate of Combat Development (DCD) APKWS, associated with a unit cost goal of only $ 8,000.
Following ATD flight trials, in 2003 the prime contractor for the APKWS-I was announced as General Dynamics, the manufacturer of the Hydra-70, with BAE Systems (selected over Raytheon) as subcontractor for the guidance and control system.
However, initial tests gave poor results, with three out of four flight tests failing.  The contract was cancelled in January
2005, the Army stating that the APKWS-I was running late and not meeting requirements.  In addition, the prices tendered for the first production lots were said to be unacceptably high.
In the following 15 months, using its own funds, BAE Systems attacked the problems that plagued the original programme, and successfully carried out three guided flights.  The principal challenges appear to have been to package the system in a small space, to develop a system that would survive the extreme temperature range encountered (from subsonic carriage at altitude to over Mach 2.0 after launch), and to design reliable wing-slot seals.

In September 2005 the US Army reopened the competition, requesting proposals under the designation APKWS-II for a system planned for service in 2008.
In April 2006 BAE Systems (teamed with General Dynamics and Northrop Grumman) was selected as the new prime contractor and was awarded a $ 41.9 million SDD (system development and demonstration) contract.  The company had won over teams led by Lockheed Martin and Raytheon Systems.
In February 2007 the US Army zero-funded the APKWS in the FY2008 budget request, but in August 2007 the US Marine Corps issued a formal statement of need for the system. In November 2008 the programme was formally transferred to the US Navy, and funding was resumed.  The hiatus is estimated to have set the programme back by at least five months, formal flight testing being delayed from August 2006 to January 2007.
Despite having dropped the APKWS, in August 2009 the US Army issued a request for information on lightweight (less than 22.7 kg) precision strike weapons under the Ampm (Aviation Multi-Platform Munition) programme to arm the Bell OH-58D.  Three types were tested in 2009, but the US Army appears to be waiting to see how the Marine Corps APKWS performs in service.
A January 2007 Government Accountability Office report (GAO-07-406SP) assessing APKWS II refers to R&D costs of $ 208.4 million, and the production of 71,637 rounds costing $1,296.6 million.  The resulting total programme cost of $1,505 million gave a unit cost of $21,000, all in FY2007 values.
The APKWS is claimed to be one-third the weight and cost of laser-guided weapons generally in use by US forces. A figure of
$28,500 has been published for the guidance and control module, and the Hydra-70 reportedly costs between $1,500 and $2,000.
In 2010 APKWS development was completed, and the first of two LRIP (low-rate initial production) contracts was awarded by the US Navy to BAE Systems.  Service acceptance trials were performed by the Navy’s VX-9 Air Test and Evaluation Squadron at Naval Air Weapons Station China Lake in California, the 35th and final round being fired in January 2012.
The 925th and final LRIP round was delivered in September 2012, two months after the award of the first full-rate contract for 1000 units.  The initial user of APKWS is the US Marine Corps, with an urgent need for more suitable attack weapons for Afghanistan.

I  Enduring Freedom
The APKWS was cleared initially on the Bell AH-1W SuperCobra attack helicopter and then on the UH-1Y Venom utility  (Bell has recently qualified it on the 407GT).  In March 2012 the first APKWS rounds were sent to Afghanistan, and operational use began later in the month.
The APKWS WGU-59/B guidance and control module is retrofitted in the body of the Hydra-70, leaving the nose-mounted fuze and warhead sections unaffected.  Four sensors are located on the leading edges of wings that unfold from slots in the body within 0.5 seconds, as the projectile leaves the launch tube. Each of the sensors is a ten-element fibre-optic seeker, giving a 40-degree instantaneous field of regard.
The sensors are required to detect a laser-designated target at 8,000 metres, and in acquisition tests have achieved much greater distances.  Control is effected by means of flaperons mounted on the wing trailing edges.
This Dasals (Distributed Aperture Semi-Active Laser Seeker) arrangement rules out lock-on before launch (Lobl), but it protects the seekers throughout the aircraft sortie, and especially while adjacent rounds are being fired.  (The only other known application for the Dasals is the ATK XM395 Precision Guided Mortar Munition).
The APKWS appears to have been conceived around the Hydra-70 with the M151 “ten-pound” high explosive warhead.  The guidance and control module adds 47 cm to its 1.472 metre length, and 4.4 kg to its 10.4 kg weight.  The guided round is normally fired from a lengthened seven-tube LAU-68F/A launcher, developed to accommodate the 1.799 metre Hydra-70 with M257/278 illuminating flare warhead.
The M152 and M282 warheads have also been approved for the APKWS, and PMA242 (the Navair project office for Direct and Time-Sensitive Weapons) has developed for this application the M149 Mod 0 flechette warhead.
The APKWS already has an effective range of 1,100 to 5,000 metres, and it is hoped later to clear it to a minimum firing range (from helicopters) of 500 metres.  By 2010 it had already met the system reliability requirement of 86%, this figure being the product of a 95% guidance reliability, 91% warhead reliability and 99% motor reliability.

I  Future Developments
In February 2011 the US Navy and Air Force awarded BAE Systems a $ 19.7 million, 27-month JCTD (Joint Concept Technology Demonstration) contract to develop a Fixed-Wing APKWS with explosively-deployed wings, to allow firings from fast jets, specifically the Republic A-10 and Boeing AV-8B.  (APKWS has already been fired from the Beechcraft AT-6 turboprop trainer.)
To minimise dispersion of the unguided Hydra-70, it has to be boosted quickly through the helicopter downwash, the rocket motor taking it to over Mach 2.0 in less than two seconds.  However, if the APKWS is launched from a fixed-wing platform, it peaks even faster, generating higher drag on the control wings as they deploy from the body.  In extreme, the wings will fail to deploy in time for their sensors to acquire the target, and the round will be unguided.
Central Command has issued a need statement for the APKWS to be integrated with the Sikorsky MH-60S Knighthawk, which would use the 19-tube LAU-61G/A launcher in place of the seven-tube LAU-68F/A.  The MH-60S would primarily use
the APKWS in defending surface vessels against fast attack craft.  A decision on this application is expected in FY2014.
Looking to the future, in September 2012 the US Navy awarded BAE Systems a contract to integrate APKWS on the Northrop Grumman MQ-8B Fire Scout drone.

I  Talon
Although the APKWS has the backing of the US Navy, and may be adopted by the US Air Force for its fast jets, it is possible that the US Army (requiring greater rocket numbers) will select a different system.  It is also conceivable that some market elements (especially in the context of ground-ground firings) may require lock-on before launch, ruling out APKWS.
The companies with most experience of producing seekers for laser-guided bombs are Raytheon and Lockheed Martin, both of which feel that the LGR battle is far from over.
Raytheon is developing its Talon under a co-operative agreement with the Abu Dhabi-based Emirates Advanced Investment Group.  The guidance module with Raytheon’s Common Digital Seeker is attached to the front end of a Hydra-70 and control is effected by three fold-out canards.
Talon test firings have taken place from hovering and moving AH-64Ds, from a minimum range of 1,200 metres to a maximum of 6,000 metres.
If the United Arab Emirates places a launch order for the Talon to arm the AH-64D, the first conversion kits will be manufactured by Raytheon at Tucson, Arizona.  Manufacture of the guidance and control section will later be transferred to EAI, but the laser seeker will remain a Raytheon product.

I  Dagr
Lockheed Martin completed development of its Dagr (Direct Attack Guided Rocket) in December 2012, having made over 40 guided flights.  These included hits on both fixed and moving targets in both lock-on before and after launch modes at ranges from 1,500 to 6,000 metres, in daylight and total darkness, and in high winds.  The company has developed two- and four-tube launchers, and has also ground-launched the Dagr from a newly developed Hellfire/Dagr pedestal launcher.
Lockheed Martin has a contract with the US Army Joint Attack Munitions Systems programme office to manufacture Dagr missiles and rail-mounted canisters for unspecified use.  This may relate to press reports that Dagr is in limited production under US funding to arm Iraqi Air Force Mi-171s and ATK AC-208Bs, and Iraqi Army Air Corps Mi-17s.
System qualification of the Dagr is scheduled for early 2013, to be followed by airworthiness release testing on several rotary-wing platforms.  A further development is the Dagr/Hellfire Strike Kit (DHSK), a bolt-on fire control system for air and surface platforms.  The latter is evidently a reference to the Joint Light Tactical Vehicle being developed to replace the Humvee.
This DHSK may be based on the four-Hellfire M299 rack that is carried below the port wing of some Hercules, and could be modified to take up to 16 Dagrs.  Such an installation is (at least) under consideration for the US Marine Corps KC-130J Harvest Hawk Capability II programme, and the Precision Strike Package for the Afsoc AC-130W Stinger and AC-130J.

I  Gatr
The basic design of the Hydra-70 dates from the early post-WW2 period, hence there may well be a market for a completely new design using modern materials.  One such missile is the 1.8-metre Gatr (Guided Advanced Tactical Rocket) being developed by Alliant Techsystems (ATK) and Elbit Systems.
The Gatr retains the MK66 propellant grain used in Hydra-70, but has an advanced nozzle, and a new tail and warhead (by ATK), combined with a mature laser seeker by Elbit, as used on its Lizard LGB and Star (Smart Tactical Airborne Rocket).  The new warhead is available in two versions: penetrator and enhanced blast/fragmentation.
The Gatr can be used in either lock-on before and after launch modes and has a range of 8,000 metres.  It has been tested on the Bell OH-58D and Sikorsky/Elbit Armed Black Hawk (ABH), and is seen as a likely candidate for Israel’s  AH-64s and AH-1s.

I  Cirit
Another laser-guided 70 mm rocket, but developed from scratch, is the Roketsan
Cirit, named after a Turkish wooden sporting javelin traditionally used by cavalry
units.  Designed to fulfil a Turkish Army requirement associated with the new TAI T129 Atak helicopter (and the AH-1W), the Cirit has a maximum range of 8,000 metres.
The Cirit has a launch weight of 15 kg and a length of 1.90 metres.  Roketsan has developed two new warheads: one high explosive and the other a multi-purpose device combining armour penetration, anti-personnel and incendiary effects.  The company has also developed twin- and four-tube launchers for the new missile.
The Cirit can be fired in a Lobl mode, or cruise on inertial guidance (using a lightweight Goodrich IMU) with laser homing only in the terminal phase.  It can also be fired in an unguided mode with wings locked retracted, to deal with pop-up short-range targets.
In mid-2012 it was reported that 100 Cirits had been delivered to the Turkish military for R&D and qualification firings, and that 2,000 production units would
be manufactured for the Turkish Army.
The Cirit is also to be tested on the Eurocopter EC635.
At IDEX in Abu Dhabi in February 2013, it was announced that the United Arab Emirates had ordered Cirits to the value of approximately $196 million.
Although most LGR developments emphasise light weight and low collateral effects, some heavy guided rockets are being developed.  Notably, Russia has developed the laser-guided 122-mm S-13L and 340-mm S-25L.
In 2009-2010 MBDA tested the 127-mm Laser-Guided Zuni Rocket, developed under a CRDA (Cooperative R&D Agreement) with the Weapons Division of the Naval Air Warfare Center at China Lake, California. This missile has a nose-mounted WGU-58/B guidance and control module, weighs 68 kg and carries an 18 kg warhead for a distance of up to 16 km.  It featured in the US Marine Corps aviation weapons roadmap of 2007, but currently appears to be on the backburner.

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