Weapons: Fast Bus to Russia

Well aware of rising concern about Russia’s growing missile strength and its apparent development of an orbital bombing system, the Pentagon moved last week to assure critics that the U.S. was not about to surrender its strategic weapons superiority. To counter the Soviet threat, Defense Department Research Director John Foster revealed, the U.S. is developing a “space bus” that can streak over enemy territory dropping thermonuclear warheads on each of many targets.

Launched into a ballistic trajectory by either a Minuteman III or a submarine-borne.Poseidon missile, the bus will be equipped with a guidance system and thrusters of its own so that it can make minor maneuvers after the main booster rocket cuts out. Arriving over the Soviet Union at a speed of 12,000 m.p.h. and an altitude of between 600 and 800 miles, it could make a series of course and speed changes, ejecting a warhead each time.

Because the bus operates at so great an altitude, only small changes in direction will be necessary to land warheads on targets hundreds of miles apart and several degrees of longitude or latitude to either side of the bus trajectory. “Each warhead is delivered to a different city,” said Foster, “or, if desired, all can be delivered within one city.”

Although Foster revealed few details about the space bus, which he called “a major breakthrough in missile technology,” development of the vehicle will be made possible by the successful sub-miniaturization of its computer and guidance systems and of the nuclear warheads themselves. Thus the bus, though small enough to be launched by the Minuteman and Poseidon missiles, will probably be able to carry as many as 20 kiloton-size nuclear warheads. Each will contain its own inertial guidance system programmed to take it to a particular target.

The new weapon, which falls into the category called MIRV (for Multiple, Independently targeted Re-entry Vehicle) in typical Pentagonese, “will multiply the capabilities of our missile systems manyfold,” says Foster. It “will assure penetration of Soviet anti-missile defenses and can deliver unacceptable damage to the Soviet Union even after we have suffered an all-out nuclear attack.”