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  • Laser Weapons for Tactical Aircraft
    Posted by David A. Fulghum 2:57 PM on Aug 18, 2010

    A possible solution for building small, powerful, airborne lasers that can be carried by manned or unmanned aircraft is a design that combines solid-state and gas-based technologies, says the Pentagon’s missile defense chief.

    A small laser in a small aircraft – far different from the chemical laser carried by the U.S. Air Force’s 747 testbed
    is considered necessary for operational practicality. The mission envisioned is Boost Phase Intercept of enemy ballistic missiles.

    “We have development programs looking at hybrid electric and gas laser,” says Lt. Gen. Patrick J. O’Reilly, commander of the Pentagon’s Missile Defense Agency says. “The concern I have about solid-state lasers is that they get hot. It is difficult to handle the heat that comes off a solid object that is lasing. There is a natural limitation to the energy it can produce. I don’t see solid-state lasers obtaining megawatt capability.

    But there is progress being made in the research and development world.

    “[Lawrence-Livermore Laboratory] is looking at taking the exciter parts of a solid-state laser and attaching it to a gas laser back end,” O’Reilly says. “That produces the optical efficiency of an electric laser while handling the thermal problems. A gas laser does not have the 100-200 megawatt limitation of a solid-state laser … so that it can achieve extremely high efficiencies.”

    Another technology that falls within the MDA’s 10-year plan is Boost Phase Intercept (BPI) of enemy ballistic missiles shortly after launch.

    “From a technical point of view, boost phase is the most attractive place to shoot down a missile,” O’Reilly says. “The challenges are timing, [position and the] Mach 9-10 interceptor missile speed you would need to shoot down a missile in the 2-4 minutes that it is boosting. The issue is practicality. How close do you have to be, and in what position? If you are on strip alert [in an aircraft with an interceptor missile] and the target missile has already launched, that’s a problem.”

    But if manned aircraft are taken out of the formula, there are other ways to make BPI a viable capability.

    “We’re interested in remotely piloted [aircraft]. “We’re studying that with the U.S. Air Force so that we can maximize the potential to have an aircraft at the right place and time to intercept.”

    Roughly that translates into operating within 500-1000 mi. of the ballistic missile launch site which in the near-term dictates the use of a small, ship-launched interceptor like the Standard Missile SM3-2B with two-tons of propellant which will be ready for a deployment decision by 2020. Reilly describes it as a first-layer defense against an ICBM threat of the future. 

    A follow-on layer could include unmanned aircraft. But unmanned aircraft systems have to operate at high altitude to keep clouds from blocking the electro-optical sensors, and the Predator Bs now involved in the test program offer the necessary performance.

    “We have the sensor capability today,” Reilly says. “We were shocked when we found out the capability of Predator for missile defense. You can be well over 1,000 km. away and you’ve got a good track on a missile [in boost phase]. We’re calibrating the accuracy and the quality [of surveillance]. They are also good at tracking … large size raids – 30, 40, 50 missiles. There could be 100 missiles in the air at once. Predator and future versions of the on-board sensor systems are fantastic at tracking missile clusters."

    Tags: ar99, boost-phase-intercept, laser, MDA

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