The prototype SR-71 made its initial test flight on December 22, 1964. Its takeoff and landing at Palmdale was a public, very 'White' debut. On hand were a number of Lockheed dignitaries. Once the SR-71 landed, they boarded a transport and took off. They did not, however, fly west, toward Burbank. Instead, the plane headed east, to Groom Lake.
Another of the Blackbird family was also to make its first, very Black, test flight that day.
The next step in reconnaissance drone development was obvious — use the technology of the A-12 to build a very high-speed, high-altitude drone.
With performance superior to that of the 147 drones, it would be much more likely to survive than the modified Firebees. The drone could also have a longer range than the Model 147. This meant they could be used to cover targets otherwise out of range.
Following the loss of Powers's U-2 over the Soviet Union, there were several discussions about using the A- 12 itself as a drone. Although Kelly Johnson had come to support the idea of drone reconnaissance, he opposed an A-12 drone, contending that the aircraft was too large and complex for such a conversion. Another possibility was to use the A-12 as a launch aircraft for an unmanned QF-104 reconnaissance drone. Several times the possibility was examined, but the CIA expressed no interest.
Although the CIA turned down the idea, Johnson found an ally with Brig. Gen. Leo Geary, director of air force special projects. General Geary arranged $500,000 from the Black projects contingency fund to begin a drone study in October 1962.
To speed up development of the drone, which was initially called the 'Q-12,' Lockheed planned to use a Marquardt ramjet engine from the Bomarc SAM.
On October 24, in the midst of the Cuban Missile Crisis, Kelly Johnson, Ben Rich, and Rus Daniell met with Marquardt representatives. From these discussions, it was clear that the Bomarc ramjet would have to be modified for use on the Q-12.[298]
A section of the Skunk Works shop in Burbank was walled off for use by the Q-12 team. The effort was kept isolated from the A-12, YF-12A, and SR-71 development. Just as the A-12 was more secret than the U-2, the Q-12 was more closely held. It required special passes to enter the walled-off section, which was dubbed the 'Berlin Wall West.'[299]
Unlike the Model 147 drones, the Q-12 would not be recovered intact.
This was done for cost reasons. Trying to put in a recovery system would make the vehicle bigger. It would require one or more large parachutes to lower it to a soft landing. A system that would allow a runway landing would add complexity, take up space, and increase both the cost and weight.
One major problem was simply slowing the drone down to a speed at which any recovery system could work.[300]
Instead, Johnson studied the possibility of recovering the Q-12's nose section by parachute. This would include not only the entire camera, but the guidance system. These were more costly than the airframe itself.
By December 7, 1962, the Q-12 mock-up was completed. On December 10, it was sent to a test site for eleven days of radar cross section (RCS) measurements. These showed it had the lowest radar cross section of any Lockheed design — a record that would be held for the next decade. The Q-12 was then returned to Lockheed for test fits of a mock-up of the camera. The drone would use a Hycon camera which used a rotating mirror to provide panoramic photos. The goal was six-inch resolution from 90,000 feet. Wind-tunnel testing of the design was also beginning.
At the same time, engine tests of the Marquardt RJ43-MA-3 ramjet were conducted in a wind tunnel that simulated the Q-12's flight profile. One concern about using a ramjet was 'blowouts.' When the drone turned, it was feared that the airflow into the engine would be disrupted. The effect was like blowing out a candle. Both Lockheed and Marquardt were amazed by the results. The ramjet could be shut down for as long as forty-five seconds and still relight. The only ignition source was the hot engine parts. [301]
When Johnson presented the results to the CIA in February 1963, he found them unenthusiastic. With the A- 12 still far from Mach 3, the U-2 operations against China, and other secret air operations such as Air America, the CIA was overextended and unable to undertake another risky project. In contrast, Air Force Secretary Harold Brown was interested in the Q-12 as a possible nuclear-armed cruise missile, as well as a reconnaissance drone.[302]
The air force interest seems to have moved the CIA to take action. On March 20, 1963, the CIA issued a contract to begin full-scale development. It assigned responsibility to Lockheed for the airframe, navigation system, and the ramjet. Funding and operational control was split between the CIA and the air force.
Once the Q-12 got under way, it was clear a major problem in development was the aerodynamics of the Q- 12/A-12 launch profile. The Mach 3 shock waves between the two aircraft could interact, creating high temperatures and stresses on the airframe. The aerodynamics of the separation also had to be determined. The Q-12 would have to pass through the shock wave formed by the A-12's forward fuselage. The Q-12 would have to separate cleanly, as there were only a few feet between its wingtips and the A-12's inward-canted fins. The center of gravity and center of lift of the combination would have to be very carefully controlled.
Wind-tunnel tests were made using metal models of the Q-12 fixed to the back of an A-12. For tests of the separation, a more complex arrangement was needed. The Q-12 model was mounted on a movable arm. This would lift it off the back of the model A-12 and provide data on the aerodynamic effects and stresses on the combination. It was not possible to reproduce actual free flight in the wind tunnel, however. [303]
Problems with the launch profile appeared early and continued into 1964.
The wind-tunnel data and calculations indicated getting the drone through the shock wave formed by the launch aircraft's fuselage would prove difficult. The ramjet would be at full power, and there could be air-fuel mixture and engine unstart problems as it passed through the shock wave. The launch would also have to be done in a pushover maneuver. It was not until May 1964 that Johnson began to feel any confidence. Although there were still problems with the launch profile, the drag of the combination, and the equipment, Johnson felt they could 'haul the thing' through Mach 1.
Ironically, the actual design and production of the drones had gone much more smoothly. The slight changes in the drone design from the RCS and wind-tunnel testing had changed the size of the payload bay. This forced Hycon to redesign the camera. By August 6, 1963, this had been completed, with no loss of resolution caused by the change. By October 1963, the drone's design had been finalized.
At the same time, the Q-12 underwent a name change. To separate it from the other A-12-based projects, it was renamed the 'D-21.' (The '12' was reversed to '21.') 'Tagboard' was the project's code name. The A-12 launch aircraft were similarly renamed, becoming the 'M-21.' The
The D-21A resembled an A-12 nacelle, wings, and vertical tail. The D-21A was 42.8 feet long, with a wingspan of 19.02 feet. The airframe was built of titanium. The leading edges of the wings, the control surfaces, and the inlet spike were all made from radar-absorbing plastic. The D-21's fueled weight was about 11,000 pounds. The reconnaissance equipment was carried in a 76-inch-long Q-bay just behind the intake. The Hycon HR-335 camera was mounted on the recoverable 'hatch.' This also carried the inertial navigation system, the automatic flight controls, and the command and telemetry electronics. These were the high-cost elements of the drone. The D-21 itself would self-destruct.[305]
A Marquardt RJ43-MA-11 ramjet, a modified version of the engine originally designed for the Bomarc SAM, powered the D-21. This could propel it at a speed of Mach 3.35. The normal cruising speed was Mach 3.25 at an altitude of 80,000 to 95,000 feet. This was far above that of the 147 drones.
The ramjet burned JP-7 fuel, the same as the A-12. The D-21's range was over 3,000 nautical miles.[306] The ramjet's burn time of two hours represented a major technical accomplishment — the Bomarc's ramjets had operated for only ten minutes.
