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Lockheed D-21

High-Altitude, High-Speed Reconnaissance Drone

Lockheed D-21

High-Altitude, High-Speed Reconnaissance Drone


The Lockheed D-21 spy drone proved largely unreliable during its time in the air - just four operational-level missions were had before the design was given up.
National Flag Graphic
ORIGIN: United States
YEAR: 1969
MANUFACTURER(S): Lockheed Martin - USA
OPERATORS: United States

Unless otherwise noted the presented statistics below pertain to the Lockheed D-21 model. Common measurements, and their respective conversions, are shown when possible.
LENGTH: 41.99 feet (12.8 meters)
WIDTH: 19.00 feet (5.79 meters)
HEIGHT: 7.02 feet (2.14 meters)
WEIGHT (EMPTY): 7,496 pounds (3,400 kilograms)
WEIGHT (MTOW): 11,023 pounds (5,000 kilograms)
ENGINE: 1 x Marquardt RJ43-MA-20S4 ramjet engine developing 1,500 lb of thrust.
SPEED (MAX): 2,212 miles-per-hour (3,560 kilometers-per-hour; 1,922 knots)
RANGE: 3,449 miles (5,550 kilometers; 2,997 nautical miles)
CEILING: 95,144 feet (29,000 meters; 18.02 miles)


Series Model Variants
• D-21 - Base Series Designation; original version air-launched from M-21 (A-12) mothership.
• D-21B - Modified version air-launched from B-52 mothership.


Detailing the development and operational history of the Lockheed D-21 High-Altitude, High-Speed Reconnaissance Drone.  Entry last updated on 7/6/2017. Authored by Staff Writer. Content ©
The Gary Powers incident of 1960 changed the way the United States spied on the Soviet Union. The subsonic, high-flying spyplane was downed by a Soviet Surface-to-Air Missile (SAM) that ended in the destruction of the aircraft and the capture of an American while elevating the mistrust witnessed between the two parties for decades. As such, thought was being given to developing fast-flying, high-flying unmanned concepts that could outrun / out-fly Soviet missile designs. The drone would serve the Central Intelligence Agency (CIA) service of the United States government to help keep a military advantage over the enemy.

Lockheed returned with its D-21 drone - a development that utilized many qualities of its A-12 high-altitude reconnaissance platform (detailed elsewhere on this site). The A-12 was the forerunner to the classic Mach 3-capable SR-71 "Blackbird" spyplane (also detailed elsewhere on this site) and followed its all-black appearance while utilizing special Radar Absorbent Material (RAM) skinning and a blended wing-body design. The D-21 actually looked the part of a single A-12 engine nacelle complete with a shockcone-like structure making up the nose assembly. It sported a single vertical tail fin and a double-delta wing mainplane form.

Lockheed D-21 (Cont'd)

High-Altitude, High-Speed Reconnaissance Drone

Lockheed D-21 (Cont'd)

High-Altitude, High-Speed Reconnaissance Drone

In theory the drone would be air-launched from the dorsal spine of an M-21, a variant of the A-12 developed exclusively for the role of drone "mothership" (hence its "M" designation). The airframe added a support pylon over the aft fuselage section on which to mount the D-21 drone and a second cockpit for the Launch Control Operator (LCO) crewman was added. The D-21 was detached by the crew when appropriate and traveled about on pre-determined waypoints - its payload strictly camera in nature. After completing its photographing of key enemy targets, it would fly to a preset rendezvous point and jettison its payload by parachute. The parachuting package was then to be picked up by a slow-flying Lockheed JC-130 "Hercules" transport aircraft for its return trip. Meanwhile, the D-21, designed as an expendable air vehicle, would self-destruct completely.

First flight of D-21 prototype was on December 22nd, 1964 - the unit was originally designated as "Q-12" with USAF hopes of also turning it into a useful cruise missile. Speeds were in the range of Mach 3.3 to Mach 3.5 and operating altitudes could reach up to 95,000 feet with a range out to 3,500 miles. To contend with the high speeds in play, the D-21 relied on skilful use of titanium at key sections. The attention paid to radar-absorbent materials and stealth design would keep the drone from being easily registered on enemy tracking software and hardware. A Honeywell avionics package was fitted as was an Inertial Navigation System (INS).

Power was from a ramjet engine developed by Marquardt Corporation. This powerplant became the RJ43-MA20S-4, a modified version of its RJ43-MA-11 series original designed to power the Boeing CIM-10 "Bomarc" SAM weapon. Since ramjet engines lacked the power to produce thrust from "zero-speed", the speed of the M-21 mothership in-air would be used by the D-21 drone to gain its initial velocity (before the ramjet could take over). Two A-12 aircraft were set aside for M-21 conversion.

Testing proved the D-21 drone largely unreliable. The fourth launch saw the unmanned vehicle detach and strike the tail section of the M-21 mothership, leading to its complete loss. While the two crew jettisoned safely, the launch officer drowned upon landing. This marked the final test launch of the D-21 from the M-21 platform so an alternative plan was drawn up to have the D-21 unit air-launched from under the wing of a specially-modified Boeing B-52 "Stratofortress" heavy bomber. Initial speed would be gained from the B-52 itself as well as through use of a rocket booster fitted to the drone. A pair of B-52H bombers were modified to a mothership standard.

Changes produced the "D-21B" designation and a first launch was recorded on September 28th, 1967. However this test proved a failure as the D-21B detached from its pylon mid-flight before an actual launch could be enacted. Testing continued into early 1968 but progress was slow and shown the whole arrangement to be lacking in consistent reliability. A successful launch was finally had on June 16th of that year but more failures continued to dog the program.

Despite this the D-21B was placed into limited service with the USAF/CIA. It conducted four total missions during its time aloft but all centered on communist China and not the Soviet Union. The first stopped responding and continued on a straight course into Soviet territory before crashing, being recovered by the enemy and thoroughly dissected. The second was able to drop its photographic payload but its parachute failed and the package was lost in the ocean. The third mission saw the same result - though the parachute deployed the recovery aircraft failed to collect the descending package in time. The final sortie over Chinese airspace came on March 20th, 1971. Again the D-21's control failed and sent the airframe crashing into enemy territory where it was promptly recovered and studied for whatever value it held.

The D-21 program came to an end in July of 1971 when it was finally realized that the arrangement was not a viable spying solution. Thirty-eight total D-21 drones of both marks were made and twenty-one of this stock was used - either successfully or not. The remainder ended in storage for a time before being sent to the scrap heap or to museums around the United States to be preserved as showpieces. Its intended high-flying, high-speed spy role was eventually overtaken by more advanced, space-based satellites placed in orbit by the American space program while the SR-71 and U-2 spy planes continued to provide decades of more reliable, faithful service all the while drones were continually being advanced along their own developmental lines.


Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.

Image of collection of graph types

Relative Maximum Speed
Hi: 5000mph
Lo: 2500mph
This entry's maximum listed speed (2,212mph).

Graph average of 3750 miles-per-hour.
City-to-City Ranges
Graph showcases the Lockheed D-21's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production (38)
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units

  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.

Altitude Visualization
Small airplane graphic
Supported Roles
Ground Attack
Aerial Tanker
A2A=Air-to-Air; UAV=Unmanned; CAS=Close Support; ASW=Anti-Submarine; AEW=Airborne Early Warning; MEDEVAC=Medical Evac; EW=Electronic Warfare; SAR=Search-Rescue
Commitments / Honors
Military lapel ribbon for Operation Allied Force
Military lapel ribbon for the Arab-Israeli War
Military lapel ribbon for the Battle of Britain
Military lapel ribbon for the Battle of Midway
Military lapel ribbon for the Berlin Airlift
Military lapel ribbon for the Chaco War
Military lapel ribbon for the Cold War
Military lapel ribbon for the Cuban Missile Crisis
Military lapel ribbon for pioneering aircraft
Military lapel ribbon for the Falklands War
Military lapel ribbon for the French-Indochina War
Military lapel ribbon for the Golden Age of Flight
Military lapel ribbon for the 1991 Gulf War
Military lapel ribbon for the Indo-Pak Wars
Military lapel ribbon for the Iran-Iraq War
Military lapel ribbon for the Korean War
Military lapel ribbon for the 1982 Lebanon War
Military lapel ribbon for the Malayan Emergency
Military lapel ribbon representing modern aircraft
Military lapel ribbon for the attack on Pearl Harbor
Military lapel ribbon for the Six Day War
Military lapel ribbon for the Soviet-Afghan War
Military lapel ribbon for the Spanish Civil War
Military lapel ribbon for the Suez Crisis
Military lapel ribbon for the Vietnam War
Military lapel ribbon for Warsaw Pact of the Cold War-era
Military lapel ribbon for the WASP (WW2)
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2
Military lapel ribbon for the Yom Kippur War
Military lapel ribbon for experimental x-plane aircraft
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.

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