One of the SAC's initial missions was to plan strategic aerial reconnaissance on a global scale.
The first efforts were in photo-reconnaissance and mapping.
Along with the photo-reconnaissance mission, a small electronic intelligence cadre was operating.
Weather reconnaissance was part of the effort, as was long-range detection, the search for Soviet atomic explosions.
In the late 1940s, strategic intelligence on Soviet capabilities and intentions was scarce.
Before the development of the Lockheed U-2 high-altitude spy plane and orbital reconnaissance satellites Corona, technology and politics limited American reconnaissance efforts to the borders, and not the heartland, of the Soviet Union.

One of the essential criteria of the early postwar reconnaissance aircraft was the ability to cruise above 40,000 feet (12,000 m), a level determined by knowledge of the capability of Soviet air-defense radar.
The main Soviet air-defense radar in the 1950s was the American-supplied SCR-270, or locally made copies, which were only effective up to 40,000 feet (12,000 m)—in theory, an aircraft cruising above this level would remain undetected.

The first aircraft to put this theory to the test was the RB-36D specialized photo-reconnaissance version of the B-36D. It was outwardly identical to the standard B-36D, but carried a crew of 22 rather than 15, the additional crew members being needed to operate and maintain the photo-reconnaissance equipment that was carried.
The forward bomb bay in the bomber was replaced by a pressurized, manned compartment that was filled with 14 cameras.
This compartment included a small darkroom, where a photo technician could develop the film.
The second bomb bay contained up to 80 T-86 photoflash bombs, while the third bay could carry an extra 11,000 litres (3,000 US gal), droppable fuel tank.
The fourth bomb bay carried electronic countermeasure equipment.
The defensive armament of 16 M-24A-1 20-mm cannons was retained.
The extra fuel tanks increased the flight endurance to up to 50 hours.
 It had an operational ceiling of 50,000 feet (15,000 m).
Later, a lightweight version of this aircraft, the RB-36-III, could even reach 58,000 ft (18,000 m).
RB-36s were distinguished by the bright aluminum finish of the camera compartment (contrasting with the dull magnesium of the rest of the fuselage) and by a series of radar domes under the aft fuselage, varying in number and placement.
When developed, it was the only American aircraft having enough range to fly over the Eurasian land mass from bases in the United States, and size enough to carry the bulky, high-resolution cameras of the day.

The standard RB-36D carried up to 23 cameras, primarily K-17C, K-22A, K-38, and K-40 cameras.
A special 240-inch focal length camera (known as the Boston Camera after the university where it was designed) was tested on 44-92088, the aircraft being redesignated ERB-36D. The long focal length was achieved by using a two-mirror reflection system.
The camera was capable of resolving a golf ball at an altitude and side range of 45,000 feet (14,000 m).
That is a slant range over 63,600 feet (19,400 m).
The contact print of this test can be seen at the National Museum of the United States Air Force at Wright Patterson AFB.
This camera is now with the National Museum of the United States Air Force at Wright Patterson AFB.

The first RB-36D (44-92088) made its initial flight on 18 December 1949, only six months after the first B-36D had flown.
It initially flew without the turbojets.
The 28th Strategic Reconnaissance Wing based at Rapid City AFB (later renamed Ellsworth AFB), South Dakota, received its first RB-36D on 3 June 1950.
Due to severe material shortages, the new RB-36Ds did not become operationally ready until June 1951.
The 24th and last RB-36D was delivered in May 1951.
A total of 24 RB-36Ds was built.
Some RB-36Ds were later modified to the featherweight configuration, in which all but the tail guns were removed.
The crew was reduced from 22 to 19.
These aircraft were redesignated as RB-36D-III.
Modifications were carried o
One of the SAC's initial missions was to plan strategic aerial reconnaissance on a global scale. The first efforts were in photo-reconnaissance and mapping. Along with the photo-reconnaissance mission, a small electronic intelligence cadre was operating. Weather reconnaissance was part of the effort, as was long-range detection, the search for Soviet atomic explosions. In the late 1940s, strategic intelligence on Soviet capabilities and intentions was scarce. Before the development of the Lockheed U-2 high-altitude spy plane and orbital reconnaissance satellites Corona, technology and politics limited American reconnaissance efforts to the borders, and not the heartland, of the Soviet Union.
One of the essential criteria of the early postwar reconnaissance aircraft was the ability to cruise above 40,000 feet (12,000 m), a level determined by knowledge of the capability of Soviet air-defense radar. The main Soviet air-defense radar in the 1950s was the American-supplied SCR-270, or locally made copies, which were only effective up to 40,000 feet (12,000 m)—in theory, an aircraft cruising above this level would remain undetected.
The first aircraft to put this theory to the test was the RB-36D specialized photo-reconnaissance version of the B-36D. It was outwardly identical to the standard B-36D, but carried a crew of 22 rather than 15, the additional crew members being needed to operate and maintain the photo-reconnaissance equipment that was carried. The forward bomb bay in the bomber was replaced by a pressurized, manned compartment that was filled with 14 cameras. This compartment included a small darkroom, where a photo technician could develop the film. The second bomb bay contained up to 80 T-86 photoflash bombs, while the third bay could carry an extra 11,000 litres (3,000 US gal), droppable fuel tank. The fourth bomb bay carried electronic countermeasure equipment. The defensive armament of 16 M-24A-1 20-mm cannons was retained. The extra fuel tanks increased the flight endurance to up to 50 hours.  It had an operational ceiling of 50,000 feet (15,000 m). Later, a lightweight version of this aircraft, the RB-36-III, could even reach 58,000 ft (18,000 m). RB-36s were distinguished by the bright aluminum finish of the camera compartment (contrasting with the dull magnesium of the rest of the fuselage) and by a series of radar domes under the aft fuselage, varying in number and placement. When developed, it was the only American aircraft having enough range to fly over the Eurasian land mass from bases in the United States, and size enough to carry the bulky, high-resolution cameras of the day.
The standard RB-36D carried up to 23 cameras, primarily K-17C, K-22A, K-38, and K-40 cameras. A special 240-inch focal length camera (known as the Boston Camera after the university where it was designed) was tested on 44-92088, the aircraft being redesignated ERB-36D. The long focal length was achieved by using a two-mirror reflection system. The camera was capable of resolving a golf ball at an altitude and side range of 45,000 feet (14,000 m). That is a slant range over 63,600 feet (19,400 m). The contact print of this test can be seen at the National Museum of the United States Air Force at Wright Patterson AFB. This camera is now with the National Museum of the United States Air Force at Wright Patterson AFB.
The first RB-36D (44-92088) made its initial flight on 18 December 1949, only six months after the first B-36D had flown. It initially flew without the turbojets. The 28th Strategic Reconnaissance Wing based at Rapid City AFB (later renamed Ellsworth AFB), South Dakota, received its first RB-36D on 3 June 1950. Due to severe material shortages, the new RB-36Ds did not become operationally ready until June 1951. The 24th and last RB-36D was delivered in May 1951. A total of 24 RB-36Ds was built. Some RB-36Ds were later modified to the featherweight configuration, in which all but the tail guns were removed. The crew was reduced from 22 to 19. These aircraft were redesignated as RB-36D-III. Modifications were carried o
Convair B-36 Peacemaker