Reagan to Get Views Today on Plan for Space Arms Deployment

President Reagan will hear the views of his chief national security officers for the first time today on a highly controversial proposal for early deployment of space-based missile defenses.

Under the plan, space-based weapons and ground-based rockets with non-nuclear warheads would be deployed in the early 1990s, about a decade earlier than previously forecast, at a cost unofficially estimated at $60 billion to $100 billion. The proposal would not involve any exotic laser or other beam weapons, technology that has not yet been proved.

Approval of the plan would signal an end in the foreseeable future to the Anti-Ballistic Missile Treaty, a move that would have major political repercussions in Congress and for U.S.-Soviet arms control efforts in general.

Democratic legislators who already have attacked the Administration for violating limits on offensive weapons under the unratified 1979 strategic arms limitation treaty will be incensed by any action that would abrogate the ABM treaty, which is viewed as the keystone of the arms control framework. Strenuous objection would also be expected from the Kremlin.

Proponents of the plan, led by Defense Secretary Caspar W. Weinberger, believe that some deployment of missile defenses must begin soon to prevent the Strategic Defense Initiative, known popularly as “Star Wars,” from withering in coming years, according to sources.

‘Lot of Research Programs’

The chief of the program, Lt. Gen. James Abrahamson, has told associates that 1987 will be “the watershed year” in which SDI “either moves forward very aggressively or becomes another research program in the Department of Defense, which has lots and lots of research programs,” one source said.

No decision by Reagan is expected at the White House meeting today of the National Security Planning Group, which is composed of key Cabinet members.

The session will consider more than half a dozen key questions on the proposal. These range from its impact on the ABM treaty and arms control efforts to the question of whether conventional SDI defenses could be constructed in the “near term” and meet criteria once laid down for it: survivability, military effectiveness and cost-effectiveness.

Essentially, SDI consists of four layers of defense corresponding to four phases of missile and warhead flight. In the first, or boost, phase, enemy missiles rising in rocket-powered flight would be targeted. During the second, or early midcourse phase, the enemy missiles coast before spawning multiple warheads. In the mid-course phase, released warheads and decoys become targets. During the final, or terminal, phase, the enemy warheads re-enter the atmosphere and plunge toward their targets on the ground.

Only in this last phase might conventional rocket interceptors be based on the ground; in the earlier phases, only directed-energy weapons, such as beams, would be based in orbit, according to the original concept, which envisaged deployment in the next century.

By contrast, a favored variation of the “near-term” SDI would consist of a three-layer defense, in which the first phase would target both the boost and early mid-course stages. All defensive weapons would be based on conventional technology, such as rocket interceptors, because the exotic technologies have not yet been proved. Terminal defense weapons would be ground-based, while defenses against the earlier phases would be stationed in orbit.

Under this concept, the basic idea would be to begin constructing the defenses as they become feasible, rather than waiting until the entire exotic system is perfected, according to SDI officials.