The US Army Space and Missile Defense Command and the Israeli Ministry of Defense have agreed to spend another $46.6 million on an antimissile laser that has been under development since July 1996. The Tactical High Energy Laser program, which has already cost the countries $130.8 million, is in its integration phase, said the primary contractor, TRW Space and Electronics Group of Redondo Beach, Calif., and is scheduled for a live-fire demonstration in late 1999 or early 2000.

The contract for the program was renegotiated in June after TRW experienced manufacturing delays and cost overruns with its subcontractors and threatened to leave the project. According to the new terms of the contract, TRW will fund half of any additional development costs until the laser downs a Katyusha rocket in flight. After a successful demonstration, the company will pay one-quarter of the costs to complete the project.

The laser system evolved out of the megawatt-class mid-infrared advanced chemical laser, a deuterium fluoride device that TRW designed for the US Navy. It is a transportable, ground-based missile defense system for use against short-range rockets such as the Katyusha, favored by the Hezbollah forces in southern Lebanon.