WASHINGTON -- A few miles from the Hollywood studios where special-effects wizards stage futuristic space wars, the United States military is preparing for the real thing.
Officers of the US Space Command in Los Angeles are developing tactics with an arsenal that George Lucas might envy, such as:
Orbiting "sentry" craft that protect US satellites from attack by loosing clouds of metal slugs to foil "killer" satellites.
"Space rods" hurled from orbit that tap the forces of gravity to penetrate buried bunker complexes on Earth.
Space-borne systems that alter the weather in a battle zone on the ground.
Never mind that these "Starship Troopers" are today office-bound theorists. And their weapons are, at best, computer simulations. Their efforts are indicative of the burgeoning importance of space as the Pentagon seeks to harness a revolution in technologies that will change the way it fights in the 21st century.
But how far the US should go in continuing to militarize space entails political, economic, and moral considerations as profound as those raised by the birth of atomic weapons. Not only would such an effort require a total reordering of constrained defense resources, but it also holds the potential for a new arms race in the cosmos.
Even so, some senior commanders say that ensuring American power in coming decades requires the US to begin aggressively developing the capabilities to control space and prevent potential rivals from using it. They advocate building satellite-killing space probes and laser beams, and orbiting weapons capable of hitting targets anywhere on Earth.
The issue is now being debated in the Pentagon, and is likely to emerge as a key factor in the shaping of US defense policies in the decades ahead.
Emerging weapons race? "It's a lot like the early days of nuclear weapons," says Andrew Krepinevich, a member of a congressional panel that released a study this month on future US defense requirements. "It's not quite clear how we are going to need to organize ourselves to use space. If you want to put yourself in a position to have options ... you have to begin exploring them now."
The US military has used space for spying, communications, and meteorology ever since it was shocked into a cold-war competition when the former Soviet Union orbited the first satellite, known as Sputnik, in 1957. Under President Reagan, it sought to develop a space-based system, popularly known as "star wars," to protect the US from nuclear missile attacks. The program was all but canceled by Mr. Reagan's successors.
But the 1991 Gulf conflict marked a turning point in military understanding the potential of space. For the first time, the US combined data from surveillance, imagery, meteorological, positioning, and communications satellites to give it unprecedented control of the battlefield.
The Gulf War was "a watershed event," says Gill Klinger, acting deputy undersecretary of Defense for space. It "highlighted ... many of the tactical applications of space that up to that point had really been unfocused."
With the Pentagon now intent on expanding "information warfare" programs to fill the gaps left by post-cold-war defense cuts, US martial power will become even more dependent on space. While the civilian space budget has dropped to $13.6 billion annually, military space spending is officially estimated at $15 billion, although independent experts say it actually totals $25 billion, or 10 percent of overall defense spending.
Precision bombs and missiles now ride satellite signals to their targets, while the services are investing in new imaging, sensing, and communications systems. The Pentagon is in the midst of deploying a system of $1 billion satellites, known as MILSTAR, designed to provide communications for 1,000 users simultaneously during a nuclear war.
"There may be room for reaching understandings with other countries.... What is lacking is a national strategy." - Zalmay Khalilzad, defense analyst.
The Pentagon is also developing more powerful satellites to replace those that provide the US with early warning of missile launches and is working on a host of other programs, including satellites that can detect submerged submarines.
This growing ability to detect and track enemy movements, intercept communications, guide weapons, and deliver data directly to soldiers in the trenches or pilots in cockpits is already forcing the military services to explore new strategies, tactics, and force structures.
Many commanders and defense experts contend that the potential of space requires that the US do even more.
"The increasing impact of space systems on military, political, and economic policy make the freedom to operate in this medium critical to US prosperity," says Air Force 2025, an Air Force study. "The need to counter future space threats and minimize US space vulnerabilities will drive the American people to accept the inevitable: weapons in space."
Three major issues are fueling such proposals: a perception that US military and intelligence satellites are becoming increasingly vulnerable to disruption, the booming availability of commercial space data to potential US foes, and a need to defend private American space investments expected to mushroom to $120 billion in the next five years.
Some experts say that with the spread of advanced technologies, it may not be beyond the abilities of some states to develop crude antisatellite weapons or systems that could jam US military and intelligence satellites, the positions of which are available on the Internet.
"We have seen that the potential for third world acquisition of considerable capabilities is large and growing," wrote Allan Thompson, a former CIA analyst, in 1995 in the journal Space Policy. "The growth [in these capabilities] is certain to continue and to be available to any group with even limited financial resources."
Another reason for the US to develop the ability to control space, some experts say, is to maintain its lead amid a huge growth in the number of nations attaining space capabilities with defense uses.
By the end of 1995, more than 30 countries and organizations - including the Czech Republic, Israel, Indonesia, and Brazil - had orbited communications or imaging satellites or individual payloads aboard satellites. The mushrooming commercialization of space, projected to top $500 billion within the next decade, is also causing concern within the US defense community.
US firms are helping fuel this trend with investments ranging from telecommunications systems to imagery satellites. Furthermore, a policy that President Clinton approved last year requires US agencies to use "to the fullest extent feasible" private space services both to promote the industry and cut their own costs. As a result, a huge percentage of Pentagon communications will be carried in the future by commercial spacecraft.
As the number of states and firms selling space services explodes, potential foes will have greater access to data they can use in the event of a conflict with the US, experts warn.
Therefore, they say, the US must develop the means to deny them such data. It can employ diplomacy, as it did during the Gulf War in pressing France to withhold commercial data from Saddam Hussein, or hit ground-based infrastructure. But the only reliable way of curtailing such data, they say, is to employ systems that can jam or destroy satellites.
The idea of the US developing such capabilities is derided by some US military officers as unrealistic and dangerous.
With US defense spending constrained for the foreseeable future to about $250 billion per year, they say the need for less esoteric hardware will be more critical to preserving US military power.
Costs aside, critics argue that a US space-weapons drive would be destabilizing, and constitute a departure from a decades-old policy of using space for "peaceful" purposes. "We are certainly headed in that direction," warns Ray Williamson of the Space Policy Institute at the George Washington University in Washington. There's a need to protect US assets, he says, "but are we really prepared to take on the rest of the world?"
Critics also dispute the contention that other states will develop capabilities to disrupt US satellite operations. And, they say, there is little chance any nation will challenge America's massive lead in space.
"We are being fed an awfully full dose of threats, domestic, foreign, and now extraterrestrial," says Bill Arkin, an independent defense analyst. "It's more part of a campaign by the national-security community to extract more of our defense dollars."
Yet, he authorized the firing of a New Mexico-based Army laser at a US satellite. Some experts regard the laser as a breach of the 1972 Antiballistic Missile Treaty.
There are now growing calls for the US to develop a broad strategy that balances the pros and cons of seeking control of space. "Given that we are going to be increasingly dependent on space, how do we protect our assets there?" says Zalmay Khalilzad, at the RAND Corp., a research institute. "There may be room for reaching understandings with other countries, there may be roles for deterrence and defense. What is lacking is a national strategy."