THE quest for ways to shoot down enemy missiles, the goal of President Reagan's ''Star Wars'' plan, is more than a quarter century old, a review of 1950's documents and recently declassified materials show. President Eisenhower began it all in the late 1950's when he embarked on a crash program of research that eventually cost billions of dollars and involved thousands of the nation's best scientists.
By 1972, when the Antiballistic Missile Treaty sharply limited all such work, the quest had produced advances not only in conventional interceptors but in such exotic devices as particle beam and laser weapons.
The story of these early efforts has been lost in the uproar over President Reagan's plan, known officially as the Strategic Defense Initiative. Yet detractors and defenders of ''Star Wars'' agree that this neglected history is crucial to understanding the international debate that has heated up in the wake of the Iceland summit meeting, which ended without agreement when Mr. Reagan refused the Soviet demand for limits on ''Star Wars'' testing.
The current debate centers on the interpretation of small sections of the 1972 treaty, whose overall intent was to ban nationwide antimissile defenses.
Detractors of ''Star Wars,'' including some of the treaty's drafters, say the treaty marked the culmination of long years of failed antimissile research. The futile expenditure of billions of dollars, they say, showed the goal was unattainable, regardless of technological progress. The treaty was drafted to eliminate not only ABM systems already in existence but also those on the horizon.
''We saw what was coming,'' said John B. Rhinelander, legal adviser to negotiators of the ABM treaty and a leading ''Star Wars'' critic. ''We tried to do an end run around lasers and that kind of thing.''
Defenders of ''Star Wars'' disagree, saying progress in top-secret technology in the 1950's and 1960's was considerable and that the 1972 treaty specifically exempted the development and testing of exotic projects such as those now at the forefront of Mr. Reagan's program.
''It doesn't cover the new technologies,'' said James T. Hackett, a former Reagan Administration official now at the Heritage Foundation, a conservative research organization in Washington. The treaty had a loophole, he said, ''to take cognizance of the fact that there were lasers out there.''
No matter how much experts differ on the meaning of the ABM treaty, both sides agree that at the time it was negotiated antimissile weaponry was far more advanced than is generally realized. The history of ABM development illuminates the positions and assumptions of both sides, they say.
The story starts in the late 1940's as American military planners struggled to cope with the threat posed by Soviet long-range bombers carrying nuclear weapons. One interceptor deployed widely throughout the United States in the early 1950's was the Nike missile, named after the winged Greek goddess of victory. Nike was to explode upon striking bombers.
By the mid 1950's, the cost of such ''air defense'' interceptors reached $30 billion a year. Then, in 1957, the Soviet Union tested its first intercontinental ballistic missile. No air-defense weapon was fast enough or accurate enough to stop a speeding warhead from space.
In response to the new ICBM threat, the Eisenhower Administration cut back on defenses against bombers and embarked on a huge, two-track program of antiballistic missile research. One track aimed to upgrade Nike interceptors,radars and computers to try to match the new threat. The other, ''Project Defender,'' explored exotic new antimissile techniques and technologies.
''Project Defender'' got under way in 1958 as a top-secret, multimillion-dollar venture involving thousands of the nation's best scientists. One proposal was to destroy Soviet missiles early in flight with Ballistic Missile Boost Intercepts - Bambi.
The scientists envisioned Bambi as hundreds of space-based battle stations using infrared sensors to track the fiery exhaust of enemy missiles. The Bambi weapon itself, propelled by rockets, would simply smash into the rising enemy missile. To increase the chance of a direct hit, the Bambi weapon would release a 60-foot rotating wire net laced with deadly steel pellets. Components were tested on Atlas and Titan missiles.
''If we went that far, that fast, with a primitive industrial base, I hesitate to think what we could do today,'' said John T. Bosma, an expert on Project Defender who participated in the 1982 High Frontier study that helped pave the way for the ''Star Wars'' plan. The study drew heavily on the Bambi proposal.
In 1959, officials at the Pentagon's Advanced Research Projects Agency, ARPA, decided to explore what they envisioned as the most futuristic arm of all, a new device known as the laser. ''Everybody at APRA was electrified at the thought of being able to create a controlled beam of light of great power,'' said Dr. Gordon Gould, a scientist who succeeded in building one of the world's first lasers in 1961 under a top-secret ARPA contract. He said the Pentagon wanted to see if lasers could be used as ''radars'' that could pinpoint enemy missiles and as ''light guns.''
