Lockheed Martin (NYSE: LMT) and L3Harris (NYSE: LHX) completed a propulsion milestone for the Precision Strike Missile Increment 4 program with the U.S. Army, according to a company statement.

The companies conducted a Direct Connect Transition Test that demonstrated a booster-to-ramjet handoff inside L3Harris' propulsion facility. The test validated the propulsion transition event for Lockheed Martin's PrSM Increment 4 design.

Flight testing of the missile is scheduled to begin this fall following the completed ground test. The propulsion system aims to enable ranges beyond 1,000 kilometers while maintaining compatibility with existing HIMARS and M270 launchers.

"The Direct Connect Transition Test shows the missile's core propulsion is not a future concept but a validated capability that can be loaded onto current HIMARS and M270 launchers quickly," said Randy Crites, vice president of Lockheed Martin Advanced Programs.

The ramjet-powered engine is designed to double the range of the baseline PrSM while using the same transport container as earlier PrSM increments. The missile can be transported by C-130 aircraft using current logistics infrastructure.

Lockheed Martin and L3Harris have invested more than $300 million combined in additive manufacturing and automation to support production capabilities. The companies stated this investment has built a production pipeline to support an accelerated fielding schedule.

Scott Alexander, president of Missile Propulsion at L3Harris, said the propulsion system "strikes a balance between capability and affordability by meeting the Army's requirements for speed, range and lethality."