Old Problems Plague New Laser Weapons
|
|
This prototype laser rifle can blind, but kill? Not any time soon.
CREDIT: US Air Force |
When the U.S. Missile Defense Agency's (MDA) Airborne Laser Test Bed (ALTB) a massive laser mounted in the nose of a Boeing 747 knocked a test missile from the sky last February, it appeared the era of high-energy laser weapons, long promised by science fiction, might finally be dawning.
A year later, things don't look so rosy for the MDA's future weapon: The ALTB botched its next two trials, and another test slated for the coming weeks could be the weapon's last chance to dodge the budgetary ax.
[See graphic: When Will I Get My Laser Gun? ]
The ALTB is not the only energy weapon that won't work reliably. Raytheon, General Atomics and many other weapons company has dabbled in laser armaments with limited success. Because of the air itself, even bright minds backed with Pentagon dollars can't seem to bring about the laser weapons of the future .
"Air is dirty, it's as simple as that," said John Pike, director of GlobalSecurity.org and an expert on defense technology and policy. "The laser beam intercepts dust in the air before it gets to the target, and this causes the laser beam to lose focus."
That problem grows more problematic the closer a weapon is to sea level, where dust, aerosols and other obstacles litter the air. Higher up, particulates are less concentrated, but the air itself can still create problems for lasers designed to engage distant targets.
At about 60 miles, even clear air cuts the power by about half, says Dr. Christopher Sorensen, a physicist at Kansas State University. Weather conditions can further compound that effect.
As for the ray guns popular in science fiction, don't look for them to replace conventional firearms anytime soon, either.
And it's not just an issue of range, but also one of durability and practicality. A "laser rifle" powerful enough to deliver the same lethality as an M16 rifle would require a hefty power source and delicate components.
"You can't help but admire the efficiency of a gun," Sorensen, who served in the American military during Vietnam, told InnovationNewsDaily. "With an M16 or an M4, you've got this projectile and it's got all of its energy packed behind it. It's going to fly as straight as a laser for 300 meters that's three football fields. So why invent a laser to zap some target at 300 meters when you've already got an M16 that doesn't need a power pack or anything like that?"
But while energy beams have yet to find a role on the battlefield, lasers play an integral role in enhancing the accuracy and effectiveness of conventional weapons. In that sense, lasers have already transformed the battlefield, Pike said, making weapons more lethal and reducing unintended casualties by guiding bombs and missiles more precisely than ever before.
