In 1994, the Department of Defense established the Advanced Concept Technology Demonstration, or ACTD, program. The ACTD process sought to address issues identified in a study published by the Packard Commission six years earlier which found that "too many of our weapons systems cost too much, take too long to develop, and -- by the time they are fielded -- incorporate obsolete technology."

The goal of the ACTD program therefore was to identify "promising projects" and expedite the acquisition process to bring needed systems to the warfighter in a more-timely manner.

The Tactical High Energy Laser, or THEL, program, a product of the Nautilus lethality studies, sought to develop a mobile directed energy weapon which could provide an inexpensive defense against artillery and short-range rockets and cruise missiles.

The proliferation of short-range rockets posed a particular threat. As "the weapon of choice for terrorist groups," they were "small, easily concealed and extremely cheap and can play havoc with [both] military bases and civilian populations."

Despite interest from the Army and the Marine Corps, in the mid-1990s, a period of downsizing and reductions, the THEL program had received only limited funding from Congressional appropriators for Fiscal Year 1996 and did not appear in the Army's five-year spend plan. Deemed ready for an ACTD in December 1995, the THEL schedule was forced to slip one year due to the lack of funds and budget delays.

Interest in the program revived after a series of successful intercept tests which included short-range Katyusha rockets in February 1996. Two months later, during a meeting with Israeli Prime Minister Shimon Peres, President Bill Clinton established an agreement under which the United States would assist Israel in the development of a tactical laser to negate the threat posed by terrorist rocket attacks. Earlier that month, Hezbollah militants had begun launching Katyusha rockets from Lebanon into Israel.

Given this urgency, the THEL "side-stepped the normal ACTD selection process" and on May 11, 1996, Secretary of Defense William Perry elevated the THEL program to an ACTD. In his directive to the service secretaries, Perry wrote: "The Department of Defense has committed to working with the Israeli Ministry of Defense … to evaluate the effectiveness of a Tactical High Energy Laser … in negating the Katyusha rocket threat."

He further stated, "this is an urgent matter for both governments and one to which I assign the utmost importance."

With a goal to establish a prototype by the end of 1997, the program moved forward quickly. In July 1996, The United States and Israel formalized their cooperative agreement for the THEL, thus making it the first ACTD system designed to be "deployed with allied forces prior to fielding with U.S. troops."

Later that month, the U.S. Army Space and Strategic Defense Command awarded an $89 million contract to TRW, Inc., to test and evaluate the effectiveness of a THEL system against short-range artillery rockets. The prototype would include a command control, communications, and intelligence subsystem; the laser subsystem; and a pointer tracker subsystem.

The THEL achieved first light at the TRW facility in June 1999. In the next year, with twelve successful intercepts, the Office of the Secretary of Defense declared the THEL ACTD successfully completed in October 2000.