Congressmen made fun of it - labeling it "dunce pack," for instance - because of the novel theory involved. The idea was to protect American missiles by basing them so close together that the explosion of the first few attacking Soviet nuclear bombs would create so much turbulence that following nuclear bombs would be thrown off course.
Said an Air Force officer yesterday, "We were defeated by the giggle factor."
But this officer, who is involved in studying possible new basing modes for the MX, said that many improvements in the technology of hardening missile silos in the last four years have kept alive the idea of closely spaced basing.
"It would still be the cheapest way of protecting silos," he said.
Reagan is seeking 100 MX missiles. Congress has authorized placing 50 in existing Minuteman missile silos, largely unprotected, at the Warren Air Force Base near Cheyenne, Wyo. But it has said Reagan must come up with an invulnerable basing system if he wants the other 50.
So far the Air Force, which has been attempting to find an invulnerable basing system for the MX for nearly 20 years, has not recommended a new basing system. But it is doing extensive studies in the search.
Two other Air Force officers confirmed that Maj. Gen. Aloysius Casey, commander of the Air Force Ballistic Missile Office at Norton Air Force Base, Calif., and top man in a search for a new MX basing system, favored an
updated version of the dense pack system.
Casey was quoted in a recent interview in the military publication Defense Week as saying, "If I had to make the choice, it would be the superhard silo" - an approach, he said, that was "the same in concept" as "closely spaced basing or dense pack."
The administration has promised to produce in the next few months a recommendation for basing the second 50 MX missiles.
Reagan's 1982 dense-pack proposal called for missiles based about 1,800 feet from one another. Today's Minuteman missile silos are from two to five miles apart.
Reagan did not give up his fight for the MX, which he calls the ''Peacekeeper," after dense pack was rejected in Congress. Instead, he appointed a special commission, headed by retired Air Force Gen. Brent Scowcroft, to study the nation's strategic posture and make recommendations.
The Scowcroft commission recommended putting the MX in existing Minuteman missile silos, even though they were only lightly protected and considered highly vulnerable to attack.
The first MX missiles are scheduled to become operational at Warren Air Force Base later this year.
A closely based deployment system for the MX missile would dovetail nicely with the thinking of some administration officials about Reagan's "Star Wars" missile defense program.
These officials favor development of Star Wars as a point defense of missile silos, rather than as a defensive system for the entire population.
They argue that missiles grouped closely together would be much easier to defend with some advanced Star Wars weapons - if the system works - than missiles scattered over a large area.