Killing Missiles From space:.

• Author: Erwin, Sandra I.
• Position: Experimental satellite planned by Air Force

Can the U.S. Air Force Do It With Lasers?

An experimental Satellite loaded with a megawatt laser could be launched into orbit some time between 2010 and 2012. Its mission would be to zap an intercontinental ballistic missile, fired from a location on Earth, hundreds of miles away.

Exotic space-based beam weapons--the so-called Star Wars systems--have been in and out of the spotlight for more than two decades. The idea of a space-based shield against Soviet nuclear missiles was embraced by Ronald Reagan in 1983. The plan faded away with the end of the Cold War. In the early 1990s, the Pentagon shifted its financial resources from celestial defenses to land-based theater systems that would protect troops from short-range tactical missiles.

But the notion of deploying a missile-defense system in space did not vanish entirely. Congressional Republicans, particularly, provided funding for military space research, even when the administration did not support the projects.

Space-based anti-missile weapons are banned by the 1972 Anti-Ballistic Missile Treaty. But, from a technological standpoint, it appears that such a system is achievable, provided that the Pentagon commits the funding. Even though the treaty prohibits the deployment of space-based missile defenses, it cannot stop. the United States from pursuing research and testing technologies.

That is exactly what the U.S. Air Force plans to do, under a program called Space-Based Laser Integrated Flight Experiment (SBL-IFX). The $4 billion program is cosponsored by the Ballistic Missile Defense Organization.

The Air Force expects to formalize the technical specifications for SBL-IFX this fall. The experiment currently is scheduled for 2013, which would require that, by 2012, the Air Force launch what is expected to be a 40-foot long, 40,000-pound spacecraft, loaded with a megawatt laser, beam-control optical mirrors and a beam-director telescope.

Only a heavy Delta IV-type launch could lift the SBL-IFX, which would be among the weightiest military payloads ever sent into low orbit (about 250 to 300 miles high). By comparison, NASA'S Hubble space telescope weighs about 30,000 pounds.

The program's director, Air Force Col. Neil McCasland, cautions that it is too early to label the SBL-FX as a definitive missile-defense option for the United States. "It is only a demonstration," he said in an interview. But there is potential, he noted, to evolve the technology toward the deployment of a global network of space-based interceptor satellites, which would destroy intercontinental-class ballistic missiles (ICBMs) using directed energy.

Congressional supporters of the SBL would like McCasland to accelerate the program and aim for a 2010 launch. It is not clear, however, how much it would cost to do that

The Pentagon budgeted $138 million annually for the program for the next two years, said McCasland.

According to a U.S. Senate source, there are "quite a few" members of Congress who would like to move SBL forward at a faster pace.

The source stressed, nevertheless, that additional funding for SBL is not guaranteed, and that the system should not be viewed as a reincarnation of Reagan's Star Wars model, but rather as a complement to the land-based national missile defense (NMD) currently in development. "SBL would be the final stepping stone" in a layered system, said the source.

The SBL-IFX is not about sending a robotic weapon into space, with no humans in the control loop, McCasland said. It is not going to detect, intercept and shoot autonomously, he explained. Like most engineering tests, it will have a carefully planned test scenario. The system will know where the launch is coming from, and the target vehicle will be flown deliberately into the engagement range of the laser. "There is no reason at this stage to make the system capable of autonomous operations," said McCasland. The ground...