Full throttle

Raytheon and Aerojet say they have successfully demonstrated the capability of a Throttling Divert and Attitude Control System (TDACS) for the Standard Missile-3 (SM-3).

The full system ground test was conducted on July 27 at Aerojet's Sacramento, California facility to simulate space flight and is said to be a major milestone toward validating the TDACS design.

TDACS -- a propulsion and manoeuvring system for the SM-3's kinetic warhead (KW) once it has detached from the third-stage rocket -- is intended for SM-3 Block IB, to be introduced in flight tests in late 2008.

"Throttling ability equals flexibility," said Edward Miyashiro, Raytheon's vice president of Naval Weapon Systems. "TDACS has the ability to dynamically vary its thrust and its operating time. It also has the potential to offer higher thrust levels, making the system more capable against various threats. TDACS is also easier to produce, thus holding the potential for significant cost savings."

Four of the 10 proportional TDACS pintle thrusters move the kinetic warhead sideways while the six other thrusters maintain the KW seeker's angular alignment and view of the target.

On-board electronic controls and software actively manage the solid-propellant gas generator's thrust level by throttling the combustion pressure up and down, similar to an automobile's gas pedal, to alternate between high thrust and coast periods.

The Missile Defense Agency and U.S. Navy jointly manage the Aegis Ballistic Missile Defense program. Raytheon Missile Systems of Tucson,

Arizona is the prime contractor for the SM-3 missile.