VANDENBERG AIR FORCE BASE, Calif. (AP) _ A $10 million prototype booster rocket for the missile defense system veered off course during a test Thursday and had to be blown up by remote control.

``For safety reasons they terminated the flight,'' base spokesman Capt. Sean McKenna said.

The three-stage rocket was carrying a mock missile interceptor. It went off course about 30 seconds after launch.

The debris splashed into the Pacific Ocean about six miles from the base.

The mishap came after the booster's first test flight on Aug. 31 was declared successful.

Thursday's test did not involve any attempt to intercept a dummy warhead.