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GMD booster launch test
While ground-based boosters like this one will provide an initial, rudimentary missile defense system, a truly effective system will need a space-based component. (credit: USAF)

Missile defense: politics, technology, and space

During the 2000 election, George W. Bush promised that, if elected, his administration would deploy a missile defense system as soon as technically possible. It looks like that promise will be kept—imperfectly, to be sure—but there is a good chance that, by October 2004, the Missile Defense Agency (MDA) will have a small number of anti-missile missiles deployed in testbed facilities in Alaska, at the US Army base at Fort Greely, and at Vandenberg Air Force Base in California. For the first time since the Safeguard system was dismantled in 1972, the Ground-based Midcourse Defense (GMD) system will give the US the capability of shooting down enemy missiles aimed at the homeland.

The problem of trying to shoot down enemy ballistic missiles is generally divided into three parts. Boost phase involves attacking the missile when it is just taking off, at a time when it is spewing out a huge heat source. This makes it easy to detect from space. The Brilliant Pebbles system, developed during the first Bush administration and canceled by Clinton’s defense department, showed how this element of the problem could be solved.

Midcourse defense is the hardest part of the puzzle. Finding and targeting a warhead or set of warheads, probably surrounded by decoys of varying levels of sophistication and effectiveness, in the cold emptiness of Earth’s upper atmosphere, is not an easy task. Powerful radar, combined with tracking systems and extremely rapid computing, can theoretically give the shooters a firing solution.

Terminal defense is a bit easier—but not much. The decoys cannot reenter the lower atmosphere, but the warhead is approaching its target at more than 25 times the speed of sound. It may be equipped to maneuver but it cannot maneuver much and, if struck by even the smallest bit of shrapnel, it will probably be destroyed.

For the first time since the Safeguard system was dismantled in 1972, the Ground-based Midcourse Defense (GMD) system will give the US the capability of shooting down enemy missiles aimed at the homeland.

The system being installed—and this must be stressed—is experimental. It is still in the testing and development phase, but it does have certain operational capabilities against a North Korean attack or against one or two Chinese long-range missiles. GMD makes maximum use of existing sensors such as the Shemya early warning radar in the Aleutians and the Defense Support Program (DSP) heat-detecting satellites. Command and control will be handled by the Air Force from the Cheyenne Mountain complex and Peterson AFB, both in Colorado. Tracking data from the some of Navy’s Aegis cruisers and destroyers will be fed into the system, making it a joint effort including the Alaska Army National Guard, as well as the Air Force and the Navy.

Both proponents and opponents of missile defense have questioned the number and realism of this years proposed system wide tests. By December GMD and its associated sensors and command and control will hardly be in place, and if it is to be properly tested then such testing will have to wait till 2005. There is also the question of cost: full scale testing supposedly costs about $100 million a pop. Until this price can be brought down, testing will always be a subject of controversy, for the simple reason that anything that costs that much will be so carefully arranged and supervised that it will never be able to match so-called “real world” circumstances.

Bringing all this together has not been easy or cheap. MDA is asking for $9.15 billion in the 2005 budget, compared to $7.7 billion last year. More than half of this total is going to the GMD part of the system. Much smaller amounts are going to the boost and terminal phase elements, while vital future technology development efforts are only getting a little more than $200 million.

By the end of this year, Bush and Rumsfeld will have a usable missile defense system. It would be a stretch to call it an operational one, but it is surely better than nothing. For missile defense advocates, it is the next stage, and the one after that, which are so worrisome. In 2005, the first Aegis Cruisers with the SM-3 missile are supposed to be ready. There will only be a few of these but they will be mobile and, in a crisis, can be deployed where needed.

The Administration now needs to be building a missile defense system than can effectively protect America and its allies on a worldwide basis, and such a system requires space-based boost phase interceptors.

Politically, the most important and the most difficult question is whether this Administration is ready to make America’s missile defense system truly effective and begin the development and deployment of space-based boost phase interceptors. They have started to work on something called Miniature Kill Vehicles (MKVs), which can swarm towards a missile in its boost phase, but these are ground launched and will have to be fast enough to chase after a missile that has already been launched. If they were based in orbit, these MKVs might be even better than the Brilliant Pebbles of the early 1990s.

Last year, one missile defense expert made it clear that the decision to place interceptors in space would be a political one. The mid-course system being deployed will be a valuable addition to a multi-layer defense but, by itself, it cannot be considered anything other than a modest first step.

Getting rid of the much-violated ABM treaty was an act of political boldness for which the President deserves full credit. The Administration now needs to be equally bold in building a missile defense system than can effectively protect America and its allies on a worldwide basis, and such a system requires space-based boost phase interceptors. The Air Force has accepted the need for America to have space superiority, so integrating that set of requirements with those of the MDA should not be too hard. It seems that the Department of Defense is moving towards the right conclusions, but is doing so in the slowest possible manner.


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