Lasers are a hallmark of military science fiction and, to casual observers, seem a long way off. This is not the case; various nations have developed lasers for military purposes, namely, point defense. The Boeing YAL-1 represents a unique take on this trend and therefore is the subject of this article.
1.0. The YAL-1: What is it?
The Boeing YAL-1 is a weapons system formerly operated by the United States Air Force (USAF) (source). It is also known as the USAF airborne laser (ABL), with YAL-1 being its operational name (source). A chemical oxygen iodine laser (COIL) fitted to the nose of a modified Boeing 747-400F is the foundation of ABL (source). Defense contractors designed the YAL-1 to intercept and destroy tactical theatre ballistic missiles during their launch stage (source). Targets would include the infamous Scud and possibly ICBMs (source)(source).
2.0. The Development of Military Lasers
Defense experts in the 1970s identified lasers as a promising technology to tackle airborne threats, including planes and missiles (source). The Defense Advanced Research Projects Agency (DARPA) pioneered early concepts, such as the Baseline Demonstration Laser (BDL) in 1973 (source)(source).
2.1. Parallel Designs
In conjunction with the US Navy and Northop Grumman, DARPA developed the Advanced Research Projects Agency (ARPA) laser soon after (source)(source). ARPA successfully shot down a missile during a US Navy test in 1978 (source). In 1980, DARPA and Northop Grumman jointly engineered the Mid-Infrared Advanced Chemical Laser (MIRACL), the first laser capable of outputting a megawatt of energy (source)(source).
The Air Force Weapons Laboratory first tested a COIL in 1977, though development continued in the decades since (source). COILs in the late 90s were eight times more powerful than earlier generations (source). The efficiency of COIL, when compared to other systems, is why it forms the foundation of the Airborne Laser used by the USAF (source).
The complexity of the systems in the [ABL] is comparable to an oil refineryJohn Kalita, Systems Integration Laboratory project manager [source]
It comprises six sedan-sized interconnected systems, each weighing approximately 3,000kg (6,500 lbs) (source). Each of these systems has 3,600 individual parts (source). COILs create enough energy in a five-second burst to “power a typical household for more than one hour” (source). The source of this immense energy comes from chemical reactions. Hydrogen peroxide decays to produce oxygen, which in turn energizes iodine (source).
This process, of course, requires fuel. COIL’s size, weight, and fuel requirements necessitate a large airframe, for which Boeings 747 is a simple choice (source). The rear of the 747 houses the COIL; the distinctive nose of the YAL-1 is the beam and fire control system (source).
2.3. Early History of Airborne Lasers
The USAF performed its first tests on the effectiveness of airborne lasers in 1981 (source). A heavily modified KC-135 used COIL in a point defense role, destroying five AIM-9 Sidewinders and a cruise missile drone (source). The program ended in 1984 because of impracticality; first and foremost, it was a proof of concept (source). Damage to the airframe due to vibrational stress and atmospheric disturbance of the laser causing ‘jitter’ dissuaded future experimentation. (source). In 1988, the vehicle flew into storage at the National Museum of the US Air Force (source). It remains there to this day (source).
2.4. Revival and Experimentation
The threat of Scud strikes on coalition forces during the 1991 Gulf War renewed the idea of airborne laser systems (source). In 1994, the US Department of Defense (DoD) awarded development contracts to two teams headed by Rockwell International and Boeing, respectively (source). The USAF now planned to discover how the atmosphere distorts the physical properties of laser weapons and how to counter this (source). A modified C-130 conducted the Airborne Laser Extended Atmospheric Characterization Experiment (ABLE-ACE) 1995 (source). ABLE-ACE found that adaptive optics could correct ‘jitter’ in laser beams, proving that such devices had practical use (source).
2.5. Development of the YAL-1
In 1996, the US Department of Defense awarded Boeings team (consisting of Lockheed-Martin and Northop Grumman) $1.1 billion to further develop their ABL concept (source). By 2004, all modifications of the 747s airframe were complete (source). The team installed Beacon and Track Illuminating Lasers (BILL and TILL) in 2006, essential components of the COIL system (source). BILL provides atmospheric data necessary for calibrating adaptive optics (source). TILL gives the target’s range and is the primary aiming point for COIL (source). In 2008, the development team finally installed the COIL system, and the YAL-1 began weapons testing (source).
3.0. YAL-1 Tests
- BILL and TILL successfully fired at a dummy target on the 15th of March, 2007 (source).
- YAL-1 first fired its COIL in September 2008, lasting one second (source).
- The first long-duration COIL firing occurred in 2009 by a parked YAL-1 at Edwards Air Force Base (source)(source).
- YAL-1 successfully intercepted a test target in January 2010, the first operational success (source).
- On the 3rd of February 2010, the YAL-1 successfully destroyed a ballistic missile in a test over the Point Mugu Naval Air Warfare-Weapons Division Sea Range (source). Another test during the same month is likewise successful (source).
4.0. Program Termination
- Cost overruns: the initial ABL contract stipulated seven operable aircraft by 2008, each costing $45 million, with an estimated total program cost of $5 billion (source). Ultimately, the program cost $11 billion and only produced one operational airframe by 2010 (source).
- Practicality: The range of the YAL-1s COIL is only 200 miles, meaning that it would need to penetrate hostile airspace to counter ballistic missile launches (source). The 747 airframe does not lend itself to action in contested airspace (source). Additionally, large fleets would be required to loiter around launch sites, which is impractical for cost and logistical reasons (source).
- Strategic issues: Because of its role as an anti-ballistic missile strategic asset, hostile action against YAL-1 could be construed as a warning of imminent attack (source). This development could cause unwanted and highly dangerous escalation.
- Collateral damage: The US is a signatory to the UN’s 1980 Protocol of Blinding Laser Weapons (source). This bans using lasers in blinding roles, regardless if the weapon is designed specifically for that purpose (source). The YAL-1’s COIL has the potential, especially if fired at or near ground level, to incidentally blind nearby individuals (source).
On the 14th of February 2011, the YAL-1 made its final flight to Davis–Monthan Air Force Base in Tucson, Arizona (source). There, it was interred in the “Boneyard” before ultimately being scrapped for spare parts in September 2014 (source).
The YAL-1 is a genuinely unique aircraft. Like its predecessors, it is a proof of concept, operating as a test-bed for laser-based interception systems. Shipping and logistics companies are looking at lasers to defend their planes from missile attacks (source). Military airborne lasers remain an area of rapid technological progress. Miniaturization of the technology allows it to be mounted on tactical and fighter aircraft (source). Paul Shattuck, Director of Directed Energy systems at Lockheed-Martin, has boasted that “[o]ur beam control technology enables precision equivalent to shooting a beach ball off the top of the Empire State Building from the San Francisco Bay Bridge” (source). How much of this is hyperbole remains to be seen.
In the end, lasers are an important future development in defense. The YAL-1 has contributed substantially to this projected trend.