The A-12 was not destined to have a long operational life. A single-seat aircraft operating under the authority of the CIA, it was never used in its intended mission of clandestine overflights of the Soviet Union. Instead, the A-12s were flown to Okinawa, and were used as part of Project BLACK SHIELD, which consisted of a total of 29 sorties flown primarily over North Vietnam, but also over Laos and North Korea, including a mission that located the USS Pueblo after its capture by the North Korean navy in the 1968 incident now known by the name of the captured vessel. Lt. Colonel Frank Murray flew four of these missions, and also flew the last flight ever of an A-12 when one codenamed "Article 131" was flown from the top secret base at Groom Lake, Nevada, to storage in Palmdale, Arizona. The A-12 was replaced in service by the SR-71, which had two seats for both a pilot and a reconnaissance officer, and which was operated until 1998 by the Air Force and 1999 by NASA. In yet another twist of irony, the "Dragon Lady" – the U-2 which the SR-71 and A-12 had been intended to replace – remains in service today, providing a flexibility and versatility still unmatched by surveillance satellites.