Alternatives to Single-Warhead Midgetman Sought : Pentagon Studies Mobile Missile Options

The Pentagon, apparently keeping its options open even as it nears full-scale development of the Midgetman missile, is considering a wide variety of new mobile weapons, defense officials said Friday.

Although Congress has ordered the development of a 30,000-pound, single-warhead mobile missile, resistance within the Pentagon has spawned repeated efforts to add warheads, increase the weight and experiment with basing modes, including the possibility of a new weapon altogether that would be deployed in extremely hardened silos to protect it against direct strikes by enemy warheads.

A senior Pentagon official, speaking on the condition that he not be identified, said President Reagan had signed a national security document directing the Pentagon to study the possibility of building a mobile missile, carrying more than one warhead and weighing up to 75,000 pounds. Officials said that such a weapon could be developed in addition to existing land-based weapons or in place of the Midgetman.

Last month, Donald A. Hicks, undersecretary of defense for research and engineering, asked the Air Force to begin preparations for a Defense Systems Acquisition Review Council session in December on the Midgetman, the unofficial name of the small intercontinental ballistic missile that Congress has ordered deployed by late 1992.

In his request, according to a Pentagon official, Hicks told the Air Force “not to leave any stone unturned” in looking at potential alternatives to the single-warhead, 30,000-pound missile. Hicks has told Congress in recent months of his interest in adding warheads to the weapon and increasing its weight.

He gave the service four weight ranges, from 30,000 to 75,000 pounds, and five possible basing modes. Until now, the Midgetman effort has focused on a mobile launcher carrying sufficient armor to protect it against a relatively close enemy strike. The weapon would be deployed on Western military bases, relying to some extent on its mobility and the unpredictability of its location for protection.

However, other basing modes being considered would include what have been described as “very hard” silos that provide greater protection than those in which Minuteman missiles are housed and in which MX missiles--the 192,000-pound, 10-warhead weapons now in production--would be placed.

In addition, Hicks suggested studies of mobile launchers deployed on the sites of Minuteman silos, which are scattered throughout the Midwest; shallow tunnels in which missiles could be shifted from site to site underground, and a system in which a capsule containing launch equipment and communications gear could be hardened against attack and moved about various missile sites to protect vital command and control functions.

The President’s arms order was an element in his decision approving the dismantling of two Poseidon missile-carrying submarines to remain in compliance with the missile-launcher limits imposed by the second strategic arms limitation treaty. The New York Times disclosed Friday that Reagan had ordered the study.

The newest study would be but the latest in a series that has been conducted on the controversial small missile. The weapon originally was recommended by a presidential commission as a complement to building 100 MX missiles.

The 500-missile system has been projected to cost $50 billion. Hicks has argued that placing two warheads on them could save $8 billion to $10 billion by cutting in half the number of expensive launchers.