A-12/SR-71 vulnerable to SAMs?

[Murmur 3,944]

On the Wikipedia page about the Lockheed A-12 (the precursor to the SR-71, operated by CIA and with a slight better performance than the SR-71), it can be read:

 

"There were a number of reasons leading to the retirement of the A-12, but one major concern was the growing sophistication of Soviet-supplied SAM sites that it had to contend with over mission routes. [...] During a flight on 30 October 1967, pilot Dennis Sullivan detected radar tracking on his first pass over North Vietnam. [...] During the second pass, at least six missiles were fired [...] He noted the approach of four missiles, and although they all detonated behind him, one came within 100 yards (91 metres) to 200 yards (180 metres) of his aircraft. [...] In response to faster, higher-flying designs like the B-70, the Soviets had begun development of greatly improved missile systems, notably the SA-5 'Gammon'. The Soviet Air Defence Forces cleared the SA-5 for service in 1967; if deployed to Vietnam, it would have provided an additional risk to the A-12. [...] Soviet air defenses had advanced to the point that even an aircraft flying faster than a rifle bullet at the edge of space could be tracked. Upgrades to Soviet radar systems increased their blip-to-scan-ratios, rendering the A-12 vulnerable."

 

On the other hand, on the SR-71 page, it can be read:

 

"The SR-71 operated at high speeds and altitudes to allow it to outrace threats. If a surface-to-air missile launch was detected, the standard evasive action was simply to accelerate and outfly the missile. [...] Its greatest protection was its combination of high altitude and very high speed, which made it almost invulnerable. Along with its low radar cross-section, these qualities gave a very short amount of time for an enemy surface-to-air missile (SAM) site to acquire and track the aircraft on radar. By the time the SAM site could track the SR-71, it was often too late to launch a SAM, and the SR-71 would be out of range before the SAM could catch up to it. If the SAM site could track the SR-71 and fire a SAM in time, the SAM would expend nearly all of the delta-v of its boost and sustainer phases just reaching the SR-71's altitude: at this point, out of thrust, it would go ballistic. Merely accelerating would typically be enough for an SR-71 to evade a SAM; changes by the pilots in the SR-71's speed, altitude, and heading were also often enough to spoil any radar lock on the plane by SAM sites or enemy fighters."

 

"Over the course of its reconnaissance missions during the Vietnam War, the North Vietnamese fired approximately 800 SAMs at SR-71s, none of which managed to score a hit."

 

 

 

So, on one hand it's said that the A-12 had become vulnerable to SAMs by the end of the '60s; on the other hand, it's said that the SR-71 was virtually invulnerable to SAMs throughout '60s-70s-80s. Isn't that a contradiction?

 

 

 

 

 

[goates 576]

That A-12 flown by Dennis Sullivan returned to base with a couple of missile fragments in its wing after flying over Hanoi. Given more time and effort, I wouldn't be surprised if the Soviets figured out a way to hit one.

 

https://www.cia.gov/news-information/featured-story-archive/2013-featured-story-archive/pieces-of-history-missile-debris-from-a-12-oxcart.html

 

SR-71s also carried more equipment, including electronic countermeasures, which would help increase survivability against SAMs.

 

http://www.defensetech.org/2012/05/31/cia-docs-the-difference-between-the-a-12-and-the-sr-71/