BOSTON
– The U.S. Missile Defense Agency (MDA) is pursuing two different concepts that would use fighter aircraft to shoot down enemy missiles launched at the
United States
.

 

Lockheed Martin Corp. and Raytheon Co. are each working on concepts for a system that would use fighters to launch interceptors at cruise missiles or short-range ballistic missiles launched from near
U.S.
shorelines.

 

Using aircraft, which can be quickly repositioned to react to an emerging threat, would be a less expensive option than lining the
U.S.
coast with ground-based interceptor systems, according to Mike Trotsky, vice president for air defense systems at Lockheed Martin Missiles and Fire Control in
Dallas
,
Texas
.

 

Lockheed Martin and Raytheon are each working on different approaches to equipping a fighter aircraft to shoot down enemy missiles. Lockheed Martin’s approach, which Trotsky discussed during a Jan. 3 conference call with reporters, would equip a fighter aircraft – most likely an F-15 – with a Patriot Advanced Capability (PAC)-3 missile Lockheed Martin is the prime contractor on the PAC-3, which was used to shoot down incoming missiles during the early stages of fighting in
Iraq
. One challenge the company faces is integrating the PAC-3 onto the aircraft, Trotsky said. The missile would likely be fired from an external weapons bay on the aircraft, he said.

 

Lockheed Martin calls its concept Air Launched Hit to Kill. The company recently completed work on an MDA study contract worth “a couple million” dollars that was intended to look at the feasibility of installing the PAC-3 missiles on the wings of a fighter aircraft, and expects to receive a follow-on award worth about $3 million shortly to begin some engineering work and prepare a proposal for a flight demonstration, Trotsky said.

 

That follow-on contract could come in a matter of days, MDA officials said Jan. 3. MDA is waiting on results from the studies conducted by Lockheed Martin and Raytheon, as well as possible future flight demonstrations, before it makes a decision on whether it will deploy an aircraft-launched interceptor, according to MDA officials.

 

Raytheon unveiled its own concept, called the Network Centric Airborne Defense Element, during a briefing for reporters in
Washington
in May. Raytheon has also focused on using an F-15.

 

Raytheon is developing a new missile for its concept based on two rockets in the military’s existing inventory. Raytheon is integrating its Advanced Medium Range Air-to-Air Missile with the seeker used on its AIM-9X rocket, which is also known as the Sidewinder. The new interceptor will also feature a second stage built by Aerojet.

 

Raytheon received a $7 million contract from MDA in May to begin working on its concept, and expects to receive a follow-on award shortly, according to Sara Hammond, a company spokeswoman.

 

Raytheon is expected to conduct an intercept test using an interim version of the rocket this summer at
White
Sands
Missile
Range
in
New Mexico
, according to the MDA officials. That test is intended to examine the ability of the seeker to discriminate between the body of the target rocket and its exhaust plume, the officials said.

 

Meanwhile, the Pentagon is also evaluating a Lockheed Martin proposal for the Infrared Search and Tracking System, a sensor that could be incorporated on the fighter aircraft for either company’s proposed interceptor system that Lockheed Martin envisions as playing a key role in locating and tracking enemy missiles, according to MDA officials.

 

MDA has asked the Defense Department’s director of defense research and engineering to provide the $2 million necessary to begin work on the Infrared Search and Tracking System under an account called Quick Reaction Special Projects, and a decision on the matter could come before the end of January, the MDA officials said.

 

While Trotsky contended that using aircraft to shoot down missiles launched near
U.S.
shores is a relatively inexpensive option, one missile defense analyst said that the cost of an effective defense against this threat would still be prohibitive.

 

Victoria Samson, a research analyst for the Center for Defense Information, a Washington-based think tank, said that the Pentagon would need to maintain a fleet of fighter jets flying continuously if it hoped to intercept cruise missiles or short range ballistic missiles. Those missiles travel too quickly over too short a distance for an aircraft to react quickly enough if it was still on the ground when the threat was detected, she said.

 

Cost is not the only possible problem associated with this concept, Samson said. Continuously flying fighter jets in sufficient numbers to cover the entire
U.S.
coastline could lead to air traffic issues, she said. The short time between launch of a cruise missile and its impact may not give the military enough time to discriminate between an incoming missile and a civilian aircraft, Samson said, noting that the military had friendly fire accidents with its Patriot missiles in
Iraq
.