Fighter Jet laser weapons are on the fast track, expected to bring new air attack options to “burn holes” through enemy targets at the speed of light. Not only are laser weapons fast, precise and low weight and drag, but they will bring a more stealthy, quiet attack advantage against air and ground targets, among other things. This is well known and ground testing of several programs are already underway with the Air Force Research Lab, the Office of Naval Research and numerous service entities involved in ground testing and ultimately flying the weapons.
Meanwhile, the Navy is concurrently developing a laser-application for its Marine Corps F-35B intended to effectively maintain the stealth fighter for future decades of war. Recognizing that the aircraft is, one might say, in its operational infancy and expected to fight until at least 2070 - the Marine Corps F-35 variant was the first of the three to enter service. Also, many of the existing F-35Bs have certainly been flying long enough to benefit from sustainment efforts.
The laser application, called “laser shock peening,” strengthens and preserves the aircraft’ s smooth stealthy exterior and composite metal materials.
A Navy report describes laser shock peening as a unique process producing a uniform result across the surface treated:
“In laser shock peening, the surface of the media is first coated with an ablative layer and covered with a water tamping layer. A high-energy laser beam is fired at the metal, which creates an area of plasma on the metal’s surface. The impact creates a shock wave, which travels through the metal, and compressive residual stresses remain. This compression helps improve the metal’s damage tolerance, fatigue life and strength…… as written in a Navy news report published on Navy.mil.
With technology verification and industry preparations already underway, laser shock peening will formally begin next year at a new F-35 depot facility now being finalized. The 16,000-square-foot facility comprises two bays, where the actual laser shock peening process will take place, and a connected area that will house the laser generator, explained Matthew Crisp, the F-35 Joint Program Office site lead at FRCE. (Fleet Readiness Center East), in the Navy report.
Laser peening will replace the legacy approach, called “Shot peening,” which sprays solid material such as glass beads or metals in kind of a sandblast fashion, Crisp explained.
“(With shot peening) you just randomly throw it at the surface, and it creates all these surface dimples. What you get is a very inconsistent surface profile, because it’s not controlled,” Crisp said.
The new process, by contrast, will strengthen the design without adding metal or weight. This is of great significance because among other things, the F-35 is built with a special blend of composite materials to minimize weight and drag while ensuring the curved, radar-absorbent stealth exterior is maintained. This process is important when it comes to flying with weapons lodged in an internal weapons bay so as not to expose contours and shapes potentially vulnerable to enemy radar detection. The process, Crisp said, has been used on the F-22 Raptor and various aircraft components.
Preserving a smooth exterior, without any kind of indentation is of critical importance to the F-35s stealth properties. Not only is the coating itself engineered to absorb enemy radar signals, but its smoothness is also critical. Should there be shapes or indents, even very small ones, they could compromise the fighter’s smooth exterior and increase the radar signature of the aircraft.
Electromagnetic pings are able to send a clearer return signal when they can bounce off edges, shapes or other configurations able to render an image of an object. The F-35 is, according to Lockheed Martin engineers, built with specific bolts, seams, curved edges and smooth, curved protruding structures by design from its inception. Continued functionality, it goes without saying, relies upon the sustainment of the effects of these engineering techniques.
The Navy report also details some of the technical elements of the advantages laser treatment provides. Lasers can of course, bring heat, precision and an ability to blanket an area without needing to use small projectiles.
Crisp explained the impact of laser peening this way, noting that it “creates a laser beam that’s actually square, and the intensity is consistent across the entire laser beam – it’s the exact same at the very edge of the beam as it is in the middle,” he said. “They come up with a grid pattern and stack the squares up right beside each other, so the entire surface of the part is completely uniform. You don’t have the weak spots in between these areas that would then induce cracking later.”
The workload of the laser treatment includes both F-35B and C models, and also encompasses F-35 aircraft owned by partner nations. FRCE will focus solely on the B variant, while Ogden Air Force Base in Utah will work on the F-35C models and take any F-35B overflow, the Navy report said.