Air Force Successfully Launches MX From Silo

VANDENBERG AIR FORCE BASE, Calif. — The Air Force for the first time test-launched an MX missile from an underground silo Friday, sending it to a target 4,100 miles away in the South Pacific.

Friday’s launch, the ninth in a series of 20 tests, was the first under “battle conditions” in which the missiles will be placed in super-hardened Minuteman silos. The missile previously has been launched from above-ground canisters.

The missile’s flight began with a steam-boosted launch at 9:39 p.m. and ended 30 minutes later at the Kwajalein Missile Test Range in the Marshall Islands.

“We had an extremely successful test,” Air Force Gen. Aloysius G. Casey said at a news conference after the launch. “The engines performed within one-tenth of 1% accuracy. . . . All six unarmed re-entry vehicles splashed down within scoring range.”

When operational, the MX will be able to deploy up to 10 nuclear warheads. The test missile launched Friday carried six unarmed Mark 21 warheads along with associated electronic test equipment, according to Lt. Col. Don Brownlee, an Air Force spokesman at the Pentagon.

100 Would Be Deployed

Under President Reagan’s plan, which has run into opposition in Congress, 100 MX missiles would be deployed in existing Minuteman silos, starting at a Wyoming Air Force base in late 1986.

The United States has 1,000 Minuteman missiles deployed in underground silos, roughly half of them armed with three warheads and the other half with one.

The Reagan Administration calls the MX an essential improvement in the nation’s nuclear arsenal because of its improved accuracy and ability to strike military targets that have been hardened by the Soviet Union against nuclear attack.

However, House and Senate negotiators recently agreed to cap MX deployment at 50 missiles.

The Air Force and Boeing Aerospace have been preparing three Minuteman silos for MX use at Vandenberg since early 1984.

Part of that work involved strengthening the silos with reinforced concrete and steel, which the military believes would make an underground MX more survivable in a nuclear strike.

The Air Force plans 11 more test flights of the intercontinental ballistic missile at Vandenberg.