Airborne High Energy Laser [AHEL]
The AC-130J Ghostrider is a medium-sized, multi-engine tactical aircraft with a variety of sensors and weapons for air-to-ground attack to replace the AC-130U/W aircraft. The Joint Task Force or Combatant Commander will employ units equipped with the AC-130J to provide close air support and air interdiction using battlespace wide-area surveillance, target geolocation, and precision munition employment. Additionally, the AC-130J provides time-sensitive targeting, communications, and command and control capabilities.
U.S. Special Operations Command (USSOCOM) engages in Direct Action (DA) activities include short-duration strikes and other small-scale offensive actions employing specialized military capabilities to seize, destroy, capture, exploit, recover, or damage designated targets. Asymmetrical threats that challenge U.S. national interests are individuals, so the U.S. military must identify, locate and negate rogue individuals in order to destroy networks. Although today’s military may have some capabilities within its repertoire that can be used for manhunting, it has not developed specialized systems to counter the non-conventional threats posed by individual terrorists. Recent military manhunts for high value targets (HVTs) have had only marginal success.
The directed energy capabilities, potentially including the AHEL, may offer possible tactical and operational advantages over conventional capabilities for certain missions requiring clandestine activities and the ability to disable vehicles, infrastructure, weapons, and individual people. Such capabilities may also offer advantages in terms of cost effectiveness, sustainability, precision and deniability.
The Air Force refers to the AHEL’s ability to damage targets as “scalable effects,” meaning the beam could be used melting a vehicle’s tires or disabling a communications antennae without any sort of explosion. In other circumstances, the AHEL could be used to start fires within enemy positions, potentially detonating stored munitions or disabling important equipment. With a standoff range on the order of 10 km, firing an invisible beam of light, such attacks would be clandestine and deniable.
These anti-materiel applications should not obscure the anti-personnel possibilities. The softest targets on the battlefield are enemy combatants. The US military has developed a variety of weapons that seek to minimize unintended "collateral damage" casualties which serve no military purpose, and indeed are too frequently counter-productive. While no precision weapon can be more precise than the intelligence that supports targetting, lasers provide the opportunity to target individual enemy combatants with minimal danger to other people in close proximity to the target.
Damage by pulsed lasers to tissues containing strongly absorbing particles may occur through biophysical mechanisms other than simple heating. In order to cause damage to the absorbing material, the electromagnetic energy of the laser pulse must be converted to thermo-mechanical energy. Small changes in laser parameters, such as duration or energy, can produce large changes in the thermo-mechanical response of the system. This causes certain laser pulse durations and energies to be especially difficult to protect against, whereas other laser regimes are especially safe. Resonant effects in laser absorption and damage that allow the duration between pulses to be tuned to channel a greater or lesser fraction of the absorbed energy into shockfront and bubble production. This allows the delivery of large amounts of laser energy to produce strong thermal effects while suppressing unwanted pressure effects, or vice versa.
Laser generation of high pressures and bubbles can cause severe effects in biological tissue. According to one calculation, at 10 kJ per shot, split into 50 pulses of 200 J spaced 10 microseconds apart (spot size on target was not specified) will, incident on flesh, blast a hole 53 cm deep, 2.2 cm wide, with a temporary cavity size of 10 cm. Incident on bone, 29 cm depth, permanent cavity diameter of 1.2 cm, shattering and fracturing out to 1.45 cm. It would be promptly fatal, as the typical human is only 20-30 cm through the torso, and the impulse would disintegrate the target into a shower of body parts and innards.
The U.S. Special Operations Command (USSOCOM) Airborne High Energy Laser (AHEL) system on the AC-130J is progressing towards flight demonstration in late FY22. USSOCOM began critical design review of the AHEL system. in August 2020. US SOCOM identified an unfunded requirement for fiscal year 2017 to accelerate the exploration of tactics, techniques and procedures, and concept of employment of an Airborne High Energy Laser (AHEL) on an AC-130 aircraft. The experimentation proposed by SOCOM included defense research laboratories and industry then working to advance directed energy systems for integration on various types of military aircraft. In May 2016 the Senate Armed Services Committee directed SOCOM to fully coordinate its activities with the High Energy Laser Joint Technology Office in order to avoid duplication of efforts and encouraged the Department to pool resources from relevant offices in support of this unfunded requirement.
In Jul 2008 Lockheed Martin Corporation entered into a definitive agreement to acquire Aculight Corporation based in Bothell, WA. Aculight is a privately held company primarily focused on providing laser-based solutions for national defense and aerospace customers. The new business unit will report to Lockheed Martin's Maritime Systems & Sensors business in Akron, OH. Founded in 1993, Aculight has approximately 90 employees.
"This transaction is consistent with Lockheed Martin's focus on acquiring companies with strategic capabilities that strengthen our core offerings and create potential for adjacent market expansion," said Chris Kubasik, Executive Vice President of Lockheed Martin's Electronic Systems business area. "Aculight's expertise in countermeasures, laser radar, and high power directed energy will be of tangible benefit to Lockheed Martin's customers in areas such as guided munitions, airborne self-protection and advanced sensors."
"Aculight's focus is to be a leader in providing high quality, innovative and cost-effective laser system solutions for our customers," said Don Rich, Chief Executive Officer of Aculight. "Becoming a part of Lockheed Martin will provide us with additional reach and resources to help achieve these goals. We are looking forward to becoming part of the Lockheed Martin team."
Aculight is known to have developed spectral beam combining technology, where several high-power beams emitting at slightly different wavelengths are combined to ramp up the overall power of the weapon. In 2004 the firm's engineering team delivered a 30 kW prototype based on this approach, with 100 kW generally regarded as the power needed for an effective laser weapon. In 2015, the company used a 30kW fiber laser weapon, known as ATHENA, to disable a truck from a mile away.
In March 2017 Lockheed Martin completed the design, development and demonstration of a new 60 kW-class beam combined fiber laser for the US Army. The high-energy source is a beam-combined fiber laser, meaning it brings together individual lasers, generated through fiber optics, to form a single, intense beam. The laser is based on a design developed under the Department of Defense's Robust Electric Laser Initiative Program, and further developed through investments by Lockheed Martin and the US Army into the 60kW-class system.
On 07 November 2017 the US Air Force Research Laboratory (AFRL) selected Lockheed Martin to lead a $26.3 million project to develop a high-power fiber laser weapon for a tactical fighter jet. AFRL, which planned to test the laser by 2021, awarded the contract as part of its “Self-protect High Energy Laser Demonstrator (SHiELD)” program.
On 05 February 2018 Lockheed Martin’s Aculight division won an initial $150 million contract to build the High Energy Laser and Integrated Optical-dazzler with Surveillance system, or “HELIOS” for short. Awarded by the US Navy, via a project called “Navy Laser Weapon System Increment 1”, the contract will see Aculight develop, build, and deliver two laser test units in fiscal year 2020 – one for a DDG 51” class US Navy destroyer, and a second for land-based testing. This contract includes options which, if exercised, would bring the cumulative value of this contract to $942,818,114.
On 14 July 2021, the Naval Surface Warfare Center, Dahlgren Division awarded Lockheed Martin a contract for technical services, integration, test, and demonstration for the AHEL system. Lockheed Martin Aculight Corp., Bothell, Washington, was awarded a $12,291,610 cost-plus-fixed-fee, indefinite-delivery/indefinite-quantity contract with a five-year ordering period for technical services, integration, test, validation, and demonstration events support for the airborne high energy laser system for the Naval Surface Warfare Center, Dahlgren Division. Work will be performed in Dahlgren, Virginia (42%); Bothell, Washington (30%); and Orlando, Florida (28%), and is expected to be completed by July 2026. Fiscal 2021 research, development, test and evaluation (Defense) funding in the amount of $100,000 will be obligated at the time of award and not expire at the end of the current fiscal year. This is a sole-source award in accordance with Defense Federal Acquisition Regulations 6.302-1(a) (2) (iii) - only one responsible source and no other supplies or services will satisfy agency requirements. Naval Surface Warfare Center, Dahlgren Division, Virginia, is the contracting activity (N00178-21-D-4412).
Laser weapons provide the advantages of speed, flexibility, precision, and lower cost per engagement that are only possible with lasers. Directed Energy operates as a force multiplier, enabling the warfighter to counter a growing range of emerging threats. For 40 years, Lockheed Martin has researched, designed, developed, and captured electromagnetic energy and elevated its power to create innovative Directed Energy solutions. It developed laser weapon systems, radio frequency and other directed energy technologies for air, ground and sea platforms to provide an affordable countermeasure alternative. It was addressing critical needs such as accuracy, mobility, size, weight and power (SWaP), cooling, and minimal collateral damage.
The development and improvement of solid state high energy lasers (SSHEL) and their consideration for weapon applications will require a laser beam director for pointing and slewing the beam to, and maintaining the beam on, the target. It has been stated that the airborne environment is one of the most stressing and severe for the application of high energy lasers as weapons. Thus the specifications for the beam director must be appropriate for the tactical platform of interest and compatible with the severity of the airborne environment. This application requires a very robust beam director with high dynamic capability to meet all the environmental and performance capabilities as well as being able to perform other missions. Since the target aperture of the beam director telescope is ~30 cm, it may also serve as an excellent surveillance tool when teamed with the acquisition sensor of the director.
Laser power to be handled by a Navy tactical aircraft beam director is envisioned as scaling from 20 kW to 300 kW as SSHEL technology evolves. General capabilities include operation from 0-40,000 ft, platform speeds of M0.1-M1.4, optical throughput >90%, residual jitter <2 urad, operational laser wavelength 1.0-1.1 um, slew rate 2 rad/sec, slew acceleration 2 rad/sec^2, and residual wavefront error lambda/8 rms @ 1.06 um. Volume and weight of the full size beam director should be less than 0.20 cubic meter and 50 kilograms.
Lockheed Martin successfully completed factory acceptance testing for the Airborne High Energy Laser (AHEL) in October 2021, in preparation for U.S. military ground and flight testing of the system. Lockheed Martin delivered the AHEL subsystem for integration with other systems in preparation for ground testing and ultimately flight testing aboard the AC-130J aircraft. In January 2019, Lockheed Martin was awarded the contract for integration, test and demonstration on the AC-130J aircraft and is on a rapid schedule to continue testing this capability.
“Completion of this milestone is a tremendous accomplishment for our customer,” said Rick Cordaro, vice president, Lockheed Martin Advanced Product Solutions. “These mission success milestones are a testament of our partnership with the U.S. Air Force in rapidly achieving important advances in laser weapon system development. Our technology is ready for fielding today.”
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