was to conduct reconnaissance missions assessing the PRC's nuclear capabilities. For this purpose, the ROC pilots flew as far as Gansu and other remote regions in northwest China. Some missions, to satisfy mission requirements including range, and to add some element of surprise, had the 35th Squadron's U-2s flying from or recovered at other U.S. air bases in Southeast Asia and Eastern Asia, such as Kunsan Air Base in South Korea, or Takhli in Thailand. All U.S. airbases in the region were listed as emergency/alternate recovery airfields and could be used besides the 35th Squadron's home base at Taoyuan Air Base in Taiwan. Initially, all film taken by the Black Cat Squadron would be flown to Okinawa or Guam for processing and development, and the U.S. forces would not share any mission photos with ROC. In the late 1960s, the USAF agreed to share complete sets of mission photos and help set up a photo development and interpretation unit at Taoyuan. In 1968, the ROC U-2C/F/G fleet was replaced with the newer U-2R. However, with the overwhelming threats from SA-2 missiles and MiG-21 interceptors, along with the rapprochement between the U.S. and the PRC, the ROC U-2s stopped entering Chinese airspace, only conducting electronic intelligence-gathering and photo-reconnaissance missions using new Long Range Oblique Reconnaissance (LOROP) cameras on the U-2R from above international waters. The last U-2 mission over mainland China took place on 16 March 1968. After that, all missions had the U-2 fly outside a buffer zone at least around China. During his visit to China in 1972, U.S. President Richard Nixon promised the Chinese to cease all reconnaissance missions near and over China, though this was also practical as by 1972 U.S. photo satellites could provide better overhead images without risking losing aircraft and pilots, or provoking international incidents. The last 35th Squadron mission was flown by Sungchou "Mike" Chiu on 24 May 1974. By the end of the ROC's U-2 operations, a total of 19 U-2C/F/G/R aircraft had been operated by the 35th Squadron from 1959 to 1974. The squadron flew some 220 missions, with about half over mainland China, resulting in five aircraft shot down, with three fatalities and two pilots captured; one aircraft lost while performing an operational mission off the Chinese coast, with the pilot killed; and another seven aircraft lost in training with six pilots killed. On 29 July 1974, the two remaining