The Real Star Wars.

O'Hanlon, a senior fellow at the Brookings Institution, is writing a book on the future military uses of outer space.

The future of space warfare doesn't seem that far off. Already the U.S. Air Force calls itself an "integrated aerospace force" and says its responsibilities extend from the surface of the Earth to distant orbital regions. The long-term plan of the military's Space Command talks about negating enemy assets in space someday, if necessary. Defense futurists envision space lasers that shoot down enemy missiles or satellites. They imagine basing weapons in low Earth orbit so they can quickly attack targets on the ground, perhaps with as little as 10 minutes' notice. They contemplate future planes that would be a hybrid of aircraft and rockets, bouncing along the top of the Earth's atmosphere with enough speed to circumnavigate the globe in three or four hours.

Which of these dreams might come true by 2012? In fact, probably none of them, even if the United States decides to pursue space weapons in the face of considerable international opposition. The pace of innovations is the issue, not costs. The next decade may not prove to be particularly revolutionary. But laboratory work will begin to develop technologies that may someday turn the above science fiction into reality. And some simpler technologies, such as small "hunter- killer" satellites that home in on an enemy asset and then destroy it explosively, may wind up being deployed--whether or not the public hears about it.

Meanwhile, the U.S. military will continue to improve its uses of communication and navigation satellites to rapidly identify, target and destroy enemy forces. It has had "spy satellites" to take pictures of ground targets for decades, as did the Soviets, to monitor arms treaties and prepare plans for a possible nuclear conflict. Such capabilities are now spreading to other countries. But the real development for the U.S. military is that satellites now help with actual war fighting. Two capabilities are key: high-precision navigation signals and lots of bandwidth for communications.

High-precision navigation, provided mostly by two dozen Global Positioning System satellites, now helps guide bombs to targets even through bad weather, smoke or light foliage. GPS guidance has helped cruise missiles strike their targets for a decade. But only in the Afghanistan war did it become mainstream, helping steer at least 5,000 weapons (primarily the Joint Direct Attack Munition, or JDAM) to within about 10 yards of their targets courtesy of a cheap, $20,000 guidance package added to an old-fashioned iron bomb. Wide-bandwidth communications also showed their worth in Afghanistan, where video shot by unmanned Predator aircraft was viewed instantaneously back in the United States, helping to track Tali-ban and Qaeda assets.

Starting in the 1999 Kosovo war, commanders also began to carry out frequent real-time videoconferences with Washington using satellite links. The growth in available bandwidth has allowed targets to be identified by one person, such as a Special Forces soldier on the ground, then attacked by a totally different system like a B-52 bomber- -all within the space of 10 to 20 minutes. In the 1991 Persian Gulf War, involving 500,000 troops, the U.S. military used satellite- communications bandwidth equivalent to what is needed ...