The US military has begun talks with contractors to potentially acquire, after 2010, the first air-launched weapon for shooting down ballistic missiles, say industry officials.
The two possible competitors - Lockheed Martin and Raytheon - are proposing variations of the Patriot Advanced Capability-3 and AIM-120 Advanced Medium-Range Air-to-Air Missile, respectively.
As well as intercepting ballistic missiles, either weapon may offer military planners the first air-launched missile capable of reaching the edge of space since a US Air Force Boeing F-15 successfully shot down a satellite in 1985 using the short-lived ASM-135 anti-satellite missile. Both contractors are nearing the end of a three-year demonstration period funded by Congressional budget "plus-ups".
Raytheon's new weapon - dubbed the Network-Centric Air Defense Element (NCADE) - has demonstrated two critical technologies.
A flight test last December showed that the infrared seeker - adapted from the company's AIM-9X Sidewinder AAM - can distinguish between the exhaust plume and the body of a ballistic missile.
An earlier bench test also demonstrated the adapted missile's novel monopropellant, hydroxylammonium nitrate, the fuel for a second-stage rocket motor developed by Aerojet.
This will replace the warhead within the AIM-120 missile frame.
Raytheon has committed to deliver the first 20 NCADE weapons to the US Missile Defense Agency by 2013 for less than $1 million each, says Mike Booen, the company's vice-president for advanced missile systems. "The power of this system is that we are adapting an existing missile, and that keeps the cost down," he adds.
But Lockheed claims the air-launched PAC-3 will offer the MDA an even less risky alternative. The modified Patriot will not require the addition of a second-stage booster rocket, or the adaptation of a seeker from a different missile.
Its only unique development item is a missile body canister, which will be jettisoned as a wing store to fire the PAC-3. Lockheed's concept - called the Air Launched Hit to Kill - is scheduled to conduct a flight test in the second quarter of this year.