WASHINGTON — Technicians successfully test fired a U.S. Air Force Minuteman 3 first-stage solid-rocket motor Oct. 24 as part of a program designed to sustain U.S. propulsion skills for strategic missiles, according to a press release issued by Northrop Grumman and ATK.

Conducted at ATK’s test facility in Promontory, Utah, this was the second quality assurance ground test for the Minuteman 3 first stage under the Solid Rocket Motor Warm Line program. ATK builds the Minuteman 3 motor; Northrop Grumman’s Missile Systems business unit of Redondo Beach, Calif., is the prime contractor on the program and responsible for the overall sustainment of the Minuteman 3 ICBM system.

“We prepare for and assess every ICBM test very rigorously,” Tony Spehar, vice president of Northrop Grumman Missile Systems, said in a statement. “The success of this Stage 1 test provides one more point of assurance of the integrity and reliability of the ICBM weapon system today and the solid rocket motor industrial base for years to come.”

As part of the sustainment program, up to 10 motor sets over two years will be refurbished by ATK under contract to Northrop Grumman. Each of the three stages is tested every year, and ground tests for the second and third stages are conducted in altitude chambers.

The refurbished Stage 1 case used in the recent test originally entered operational inventory in 1961.

ATK has manufactured more than 4,000 Minuteman motors since the ICBM program began. The company also recently finished a 10-year Minuteman Propulsion Replacement program that produced about 1,800 re-manufactured motors.