B-70 Variants - a History that Never Was

[ORAC]

Interesting how much they thought about dropping or launching stuff in supersonic flight as early as back then. The SR-71 even tested it.
Strange that those plans never seem to have materialized, say to launch ramjet-drones into contested airspace, at least it got never admitted.

Lockheed D-21......

https://en.wikipedia.org/wiki/Lockheed_D-21

.....The fourth and final launch from an M-21 on 30 July ended in disaster. Unlike the three previous launches this one was performed straight and level, not in an outside loop to assist in the separation of the drone from the aircraft. The D-21 suffered engine problems and struck the M-21's tail after separation, leading to the destruction of both aircraft. The two crew ejected and landed at sea. The pilot, Bill Park, survived, but the Launch Control Officer, Ray Torrick, drowned.[10][11]

Following the accident, Johnson suggested launching the D-21 from the Boeing B-52 Stratofortress bomber and adding a solid rocket booster to get it up to speed.[12] ......

Four operational missions with the D-21B took place under the codename of Senior Bowl. These were conducted over the People's Republic of China from 9 November 1969 to 20 March 1971 to spy on the Lop Nor nuclear test site. The USAF's 4200th Support Squadron, based at Beale Air Force Base, California, flew the missions, usually from Andersen Air Force Base in Guam.[19]

The Chinese government never reported spotting the D-21B in flight. The first one failed to turn around and continued straight on, crashing in the Soviet Union.[20] Another test flight was conducted on 20 February 1970 in a successful attempt to correct any problems. The second operational mission, however, was not until 16 December 1970. The D-21B reached Lop Nor and returned to the recovery point, but the hatch had a partial parachute failure and was lost at sea with its photographs.[17]

During the third operational mission, on 4 March 1971, the D-21B flew to Lop Nor and returned, and released the hatch, which deployed its parachute, but the midair recovery failed and the hatch fell into the water. The destroyerthat tried to retrieve the hatch ran it down and it sank. The fourth, and last, operational flight of the D-21B was on 20 March 1971. It was lost over China on the final segment of the route over China's Yunnan province;[21] wreckage was found by local authorities. In 2010, after being in the junkyard of the China Aviation Museum for years, the wreckage was moved to the exhibition area.[22]

On 23 July 1971, the D-21B program was canceled due to its poor success rate, the introduction of a new generation of photo reconnaissance satellites, and President Richard Nixon's rapprochement with China.[23] .....