[Llarry]

The initial U-2 photo reconnaissance overflights of the USSR in June 1956 came as a shock to the Soviets. They had already experienced "high altitude" overflights by Canberras but the U-2 upped the ante considerably as they cruised over Warsaw Pact and Soviet territory with impunity taking photographs at altitudes about 10,000 feet higher than previous aircraft. The flights were conducted by CIA-owned U-2s and Soviet protests were met with denials that any U. S. military aircraft were involved.

The story of the U-2 overflights is well known, and I won't go into details here except to add that the flights ceased in May 1960 when a CIA U-2 was shot down by Soviet S-75 Dvina (SA-2 Guideline) missiles.

The wreckage of the downed U-2 gave the Soviets some insight into the engineering of such an aircraft and the Beriev design bureau was given the task of copying the American aircraft. The resulting Beriev S-13 was never completed.

Yakovlev was tasked with modifying a Yak-25 with extended wings to give the aircraft high altitude capability -- somewhat like the Americans had done with the Canberra-based RB-57D and RB-57F. The result was the Yak-25RV (NATO Mandrake), which did not have quite the altitude capability of the U-2. The Yak-25RV was adopted in 1961 and 155 were built. Many were used in unmanned mode.

One vital mission for a high-altitude aircraft was destroying the American camera-carrying balloons that used prevailing wind patterns to overfly much of the USSR snapping photos. The Myasishchev design bureau was tasked with developing a high-altitude balloon interceptor. The result was a prototype Article 34, which was completed in 1978 -- well after the balloon program had ceased. The Article 34 was armed with two 23mm cannon firing upward to the rear of the cockpit and could also carry two air-to-air-missiles. The program ended in disaster when during taxi tests, the aircraft hit a snowbank and was destroyed.

Myasishchev did not give up. They refined the design and the resulting M-17 Stratosphera (NATO Mystic A) flew in 1982. At least two of these were built. The twin cannon were retained but I believe the AAM capability was deleted. By the time the M-17 appeared, the balloon program was defunct; the U.S. now used satellites for photo recon.

Myasishchev continued to develop the concept and the M-55 Geophysica was the final design. The M-55 had twin engines and first flew in 1988. Although such an aircraft had potential for high-altitude photo recon, it was used mainly for scientific research purposes. 5 aircraft were built. Of note, Russia may be trying to restore one M-55 to flying status for use in the war with Ukraine. I suspect that such an aircraft, if flying at 70,000 feet over Ukraine or Russia, will prove to be vulnerable to air defense missiles.

All these Soviet efforts topped out at about 70,000-foot altitude. It's worth noting that the modern U-2S can get close to 80,000 feet these days.