WASHINGTON — The U.S. military has succeeded for only the second time in shooting down an intercontinental ballistic missile, but Pentagon officials warned Sunday that much more development would be needed before the technology could reliably destroy real weapons.
A prototype interceptor fired from Kwajalein Atoll in the Marshall Islands demolished a dummy warhead 140 miles above the Pacific late Saturday, scoring the first hit for the Pentagon's missile defense program since October 1999. In between, there have been two failed tests, which raised doubts about the costly program's future.
The technical feat is expected to encourage Republicans in Congress who want the Bush administration to abrogate the 1972 Anti-Ballistic Missile Treaty and deploy national missile defenses soon. It is also likely to complicate the efforts of Democrats who want to cut the Pentagon's proposed $8.3 billion missile defense budget for 2002.
Michael O'Hanlon, a military analyst with the Brookings Institution, a policy organization, said many Democrats were trying to argue that "the technology is immature, the cost too high and the threat not imminent, so let's slow it down or even not build it."
"This test," he added, "will make it harder to make that argument."
But senior Pentagon officials tried to play down the significance of the $100 million test, saying that it was the first in a long line of increasingly challenging tests.
"We've got a long road ahead," said Lt. Gen. Ronald T. Kadish, director of the Pentagon's Ballistic Missile Defense Organization.
In one sign of the Pentagon's efforts to appear low key about the test, Secretary of Defense Donald Rumsfeld stayed home on Saturday rather than watch the test from his Pentagon office. He also did not release a statement following the intercept.
On Capitol Hill, missile defense enthusiasts hailed the test as reason to push ahead quickly with the program. "We're going to do it," the Senate minority leader, Trent Lott of Mississippi, said on Fox News Sunday. "We should put this right at the top of the agenda, not allow it to be pushed aside by Democrats."
But Democrats urged the administration to go slow, both in deploying the new technology and in negotiating with Russia to amend or replace the ABM Treaty. Moving too quickly, they argued, could lead to an unreliable system or spark a new arms race with Russia or China.
"If you put this on a fast-track testing regime, it could hamper its ability to move forward," said Rep. Ellen Tauscher, D-Calif., who supports building a limited missile shield. "This is a good thing for the program, but we are nowhere near deployment."
Sen. Jack Reed, D-R.I., who sits on the Senate Armed Services Committee, said, "We're a long way from something that is routine and deployable."
The test was denounced by Moscow Sunday morning. "Why take matters to the point of placing under threat the entire internationally agreed structure of nuclear disarmament and nonproliferation, including its core, the 1972 ABM treaty?" said a Russian Foreign Ministry spokesman, Alexander Yakovenko, in a statement.
At a news conference in Washington early Sunday morning, Kadish said the test was intended to "build confidence" in hit-to-kill technology and was similar to the last intercept attempt, in July 2000, which failed. Both tests were supposed to check whether basic elements of the complex system, including communications networks, infrared sensors, radar equipment and battle-management controls could work together.
Kadish, standing beside a life-size model of the $25 million kill vehicle, cautioned that scientists would need weeks or even months to finish analyzing the test results. "We do not know for certain that every objective was met," he said. "In all probability, some of them were not."
His caution may be based in recent experience. In October 1999, the Pentagon hailed its first intercept attempt as a complete success after the kill vehicle collided with the mock warhead. But later analysis showed that the kill vehicle had drifted off course and had initially homed in on a decoy balloon instead of the warhead.
Critics of the program have asserted that the decoy, which happened to be drifting near the warhead, actually drew the kill vehicle toward the target. Pentagon officials have rejected that interpretation.
The test began at 10:40 Saturday night when a Minuteman II intercontinental missile carrying the mock warhead and a decoy balloon made of a highly reflective synthetic material lifted off from Vandenberg Air Force Base north of Los Angeles. Twenty-one minutes later and 4,800 miles away, an interceptor rocket shouldering the 120-pound kill vehicle blasted off from Kwajalein.
In the next 8 minutes, the kill vehicle separated from its booster, oriented itself in space with help from the stars, used sensors to distinguish the decoy balloon and home in on the target, and finally maneuvered to smash into the warhead at 16,200 miles an hour.
Closed circuit monitors at the Pentagon showed a bright flash when the two projectiles apparently collided at 11:09 p.m. The screen immediately switched to a view of the Kwajalein control room, where Boeing and military workers could be heard cheering and Maj. Gen. Willie Nance, the program's executive director, could be seen shaking hands and receiving backslaps from jubilant aides.
Even before the test, critics had said that it would be flawed because its lone decoy balloon was round and therefore easily distinguishable from the cone-shaped target. In a real attack, those critics argued, an adversary would use multiple decoys shaped like real warheads. The Pentagon has said it intends to use those kinds of more sophisticated countermeasures in future tests.
The test came just two days after senior Pentagon officials outlined to Congress the most detailed vision yet of the Bush administration's plans to accelerate testing on an array of anti-missile technologies, including land-based missiles, sea-launched interceptors and airborne lasers.
That aggressive schedule, for which the Pentagon has requested a $3 billion increase in missile defense spending for 2002, is likely to clash with the ABM Treaty within months, the officials told senators. Under that plan, the Pentagon says it intends to conduct as many as 17 flight tests involving ground- and sea-launched missiles over the next 18 months.