Deja vu all over again: photonics and missile defense

Photonics, once the U.S. Air Force's primary technological thrust to succeed electronics in the sensing, data distribution, and signal processing functions of future weapon systems, is receiving new attention for homeland security applications.

By John Rhea

WASHINGTON — The increasingly turbulent global climate, based on the Sept. 11, 2001 terrorist attack and the growing concerns over Iraqi weapons of mass destruction, is breathing new life into two technologies that have lain dormant in recent years.

Photonics, once the U.S. Air Force's primary technological thrust to succeed electronics in the sensing, data distribution, and signal processing functions of future weapon systems, is receiving new attention for homeland security applications.

With President Bush's Dec. 17 decision to proceed with the deployment of a minimal ballistic missile defense system, the old issues of detection and confirmed destruction of incoming warheads will also demand considerable attention on the part of the high-technology industries.

There may be some synergism here. The functions are remarkably similar. In both cases early detection is essential. An evolving technology base predicated on driving down costs to achieve affordability and improving reliability to provide confidence to the users should be a valuable national asset.

In fact, when the Air Force originally set up its Photonics Center in 1987 at what is now the Air Force Research Laboratory in Rome, N.Y., one of the principal tasks was to tackle the battle-management problem of what we then called the Strategic Defense Initiative, or SDI. The idea at the time revolved around a technology base embracing optical fiber data distribution and photonic signal processing to support strategic and tactical weapon systems.

This idea is being revived. At a conference on photonics for homeland security held in early December in Alexandria, Va., sponsored by SPIE (formerly the Society of Photo-optical Instrumentation Engineers) in Bellingham, Wash., speakers discussed what they called a "deterrent-rich" environment in which photonics would speed the flow of vital information to the defenders.

Roger Werne, chief engineer at the Nonproliferation, Arms Control, and International Security Directorate of the Lawrence Livermore National Laboratory in Livermore, Calif., said that the Cold War "eye for an eye" deterrent was no longer applicable for terrorists willing to sacrifice their lives to achieve their goals.

Today, Werne stresses, the defenders must convince the terrorists that they will be caught or killed without achieving their goals. He sees a supporting role for photonics in the detection and network-communications functions.

At the same conference Arthur Sedlacek III, a scientist at the Brookhaven National Laboratory on Long Island, proposed using Raman lasers currently employed in atmospheric research to detect chemical and biological threats. These could be important tools for first responders, Sedlacek says.

Like the electronics industry with which it interfaces, photonics is evolving with a sort of rhythm of its own. The demands of the commercial marketplace are setting the pace, and the military establishment can cash in on this research.

That's not the case for ballistic missile defense. If the threat is as imminent as President Bush maintains, the system must work to perfection the first time and every time it is called upon to destroy incoming warheads.

This, in turn, presumes an adequate technology base, which the system's critics doubt is here yet. There have been remarkable advances in signal processing — electronic as well as photonic — but the sensing from ground-based radars and satellite-borne infrared sensors remain what the Air Force calls "the long pole in the tent."

Incredibly, the problems to date have been principally with the ground-based rocket interceptors. This should be the easy part. The so-called rocket science isn't science at all, but engineering, and a mature technology as well. Nonetheless, the Air Force leaders have succeeded in only four of five attempted intercepts from the Kwajalein Atoll even though the dummy warheads were not accompanied by the sort of primitive decoys that could be expected from an aggressor.

The President's plan calls for an additional $1.5 billion for the next fiscal year, on top of $8 billion already funded annually for ballistic missile defense, to begin deployment of six ground-based interceptors at Fort Greely, Alaska, by the end of 2004. Ten more would be added there the following year plus four interceptors at Vandenberg Air Force Base, Calif.

In parallel, the Navy would deploy 20 Standard Missile 3 interceptors on its Aegis destroyers, and the Army would deploy Patriot PAC-03 missiles to counter tactical missiles similar to the obsolete Scuds used by Iraq in the Persian Gulf War.

The disturbing issue here is rushing to deployment before the necessary technological homework has been completed. President Clinton — wisely, in my view — resisted the sort of stampede that is now under way in Congress and elsewhere in Washington.

The opposing argument, however, is that the engineers could fritter away their time interminably on the development before they throw the hardware over the fence to the users. Samuel Johnson put the matter succinctly: "Depend upon it, sir, when a man knows he is to be hanged in a fortnight, it concentrates his mind wonderfully."

On one point everybody is agreed: this is indeed a bare-bones system intended to counter only rogue states, not the Russians or Chinese, with whom the United States has relatively friendly relations. They have made the predictably unhappy noises about the United States abrogating the 1972 Anti-Ballistic Missile Treaty, but this is hardly a primary area of concern.

The supporting technologies will evolve regardless of what anybody in the Pentagon or in the new Department of Homeland Security does about them. The availability of additional funds will certainly be helpful, but all concerned with this development would be wise to watch for attached strings.

One chilling comment by Werne at the SPIE conference illustrates this point: "We don't want our adversaries to know how capable our detectors are so we can't be so open about the technology." He called that the "blessing and curse" of creativity vs. vulnerability.

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