Time： 2024-08-18  韦克威科技

Why was the SR-71 Blackbird reconnaissance plane, which had a sci-fi appearance, suddenly retired?

Yesterday, in the "Big Ivan Q&A" column, we mentioned to everyone the highly confidential SR-71 "Blackbird" high-altitude high-speed strategic reconnaissance aircraft of the US military during the Cold War. Some readers have suggested that the retirement of the "Blackbird" strategic reconnaissance aircraft is due to the significant development of optical imaging reconnaissance satellites. So, is the retirement of SR-71 Blackbird really just due to being replaced by optical reconnaissance satellites?

Da Ivan believes that it is not entirely true. From the development history of post-war optical reconnaissance satellites in the United States, as early as the late 1970s, the KH-11 optical reconnaissance satellite launched by the "Canaan" project had a census resolution of about 0.5 meters.

KH-12 reconnaissance satellite

By the early 1980s, due to the addition of adaptive optics imaging processing and the elimination of atmospheric thermal convection distortion, the resolution had increased to around 0.2 meters. In the "Lock Eye" program that began in the 1980s, the KH-12 optical reconnaissance satellite launched achieved a census resolution of 0.1 meters, which has reached the level of optical reconnaissance equipment equipped on the SR-71 reconnaissance aircraft. However, even so, the SR-71 was actually deployed in orbit only six or seven years earlier than the KH-11 reconnaissance satellite. Even after the extensive use of the KH-12 reconnaissance satellite, the SR-71 did not retire from active service in the US military, but was finally retired in 1997, by which time the KH-12 series of reconnaissance satellites had been in service for more than ten years.

In summary, the KH-11 and KH-12 reconnaissance satellites are the main factors replacing the SR-71 strategic reconnaissance aircraft, and Da Ivan believes that the reasons are not sufficient. After all, compared to reconnaissance satellites, SR-71 also has its own unique advantages - its mission response time is very high and the revisit rate is higher. Due to the limited deployment of KH-11 and KH-12 satellites, their revisit rates to specific areas are relatively low. In 1 to 2 days, the data transmission and processing on board still need to delay some time, which can easily delay the observation timing for some targets that require continuous observation, or hidden and time sensitive targets.

In contrast, the SR-71 has a relatively fast response time for missions. SR-71 located in the United States or East Asia can prepare for missions in a shorter period of time, completing them within a few hours and obtaining reconnaissance images on the same day after returning to base. The task chain has been compressed from two to three days to within one day, which is a great advantage for the reconnaissance department. SR-71 and reconnaissance satellites are not so much in a "replacement" relationship as they can complement each other's strengths.

Therefore, the retirement of the SR-71 reconnaissance aircraft is considered by Ivan the Great to be the result of comprehensive factors, and reconnaissance satellites are only one of them, and not necessarily the most important factor. For the US military, the reliability of the SR-71 is not high and maintenance costs are high (the Cold War has ended and landlords have no surplus food); The advanced air defense systems of China and the Soviet Union began to be deployed in large quantities (especially the Soviet S-300PM, SR-71, which was hit by S-300 during several missions near the end of the Cold War in the Baltic Sea); A new generation of "economical" unmanned reconnaissance aircraft is beginning to emerge (RQ-4 "Global Hawk" is not good); Especially most importantly, after the end of the Cold War, the US military no longer needed the SR-71, a "expensive commodity" prepared for high-intensity confrontation, which was the ultimate factor for its retirement. This is the result of a comprehensive effect.

Source: Military and Military Express