Thursday’s Roll-up of Missile Defense News

What do this:

and this:

have in common?

How about this:

ABL Test a Success (By MARTIN SIEFF UPI Senior News AnalystWASHINGTON, July 17 (UPI) )

Boeing announced Friday that with its partner companies and the U.S. Missile Defense Agency it had "successfully completed a key Airborne Laser flight test."

The successful ABL test had shown "the weapon system’s ability to actively track an airborne target, compensate for atmospheric turbulence and fire a surrogate for its missile-killing high-energy laser," the company said in a statement.

"During the test, the modified Boeing 747-400F took off from Edwards Air Force Base, Calif., and used its infrared sensors and its track illuminator laser (TILL) to find and track an instrumented target board located on the U.S. Air Force’s NC-135E Big Crow test aircraft," the Boeing statement said.

"The Big Crow then fired its beacon laser at the ABL aircraft to allow ABL to measure and compensate for laser beam distortion caused by the atmosphere. Finally, ABL fired the surrogate high-energy laser (SHEL) at the Big Crow target board to simulate a missile shoot down," the statement said.

"With the exception of ABL’s beacon illuminator laser (BILL), this flight test demonstrated the entire engagement sequence from target acquisition to pointing and firing the SHEL," it said.

"This successful test shows that ABL can find and track a target, use its beam control/fire control system to compensate for atmospheric turbulence, and fire a surrogate high-energy laser to simulate a missile intercept," said Pat Shanahan, vice president and general manager of Boeing Missile Defense Systems. "We have now demonstrated most of the steps needed for the Airborne Laser to engage a threat missile and deliver precise and lethal effects against it."

The first aircraft is obviously the Airborne Laser (ABL), designed to provide a boost-phase kill capability against MR/IR/ICBM’s.  The second a/c is a NC-135 BIG CROW – basically an EC-135 that has been modified to serve as an airborne target for testing the various laser tracking/illuminating systems on the ABL.  Note the white profile on the fuselage – it rughly conforms to the size of an MRBM/IRBM and is populated with sensors to determine localization of the laser spot from the ABL.

The big deal about this is one of the significant challenges the ABL faces is that the intercept/kill takes place in the lower reaches of th atmosphere instead of the high atmosphere or in space.  As a result, it has to deal with distortions and energy absorbtion caused by the atmosphere (variations in pressure, moisture/vapor presence, etc. – all the things that make up weather as we know it).   To overcome atmospheric effects, the HEL uses deformable mirrors to adapt and conform the kill beam.  Compounding the challenge is the fact that it has to be done over an extreme distance against a very small, accelerating target.  On top of that, since the kill mechanism is via detonation of the missile’s fuel, there is a small target area and narrow window of opportunity to exercise the option.  In that timeframe, the ABL has to locate, track and illminate the target with a tracking laser and the high-energy laser carried in the turret in the nose of the aircraft (the tracking laser is housed seperately).  

The test decribed above was signatory in that it tested almost the entire system, save the HEL which will be integrated into the ABL in the coming months.  Still taking baby steps, but they are important ones and signify a signficant level of technological progress unmatched elsewhere.