The objective of the mission was to obtain aerial images of Eastern Europe, the Soviet Union and China using a photographic reconnaissance payload known as WS-119L. The flight was part of GENETRIX, a covert military operation carried out between January and February 1956 by the United States Air Force and other agencies. The program involved the launch of stratospheric balloons from sites in Scotland, West Germany, Norway and Turkey at a time when high altitude spy planes and satellites were still not operative.
The WS-119L system was a complex device with several separate elements as can be seen in the scheme at left: the suspension system, the photographic gondola, associated support systems and the balloon (not shown). The balloons used for the mission were zero pressure polyethylene balloons designed and manufactured by General Mills Inc. Hydrogen was used as lifting gas.
The suspension system connected the fully instrumented gondola to the balloon by means of a load strap threaded thru and attached to a 24 foot personnel parachute. It helped to return to ground the empty ballast boxes, rotator and long bar at the end of flight, and as a safety measure in case of balloon burst to avoid free-falling objects inflicting damage to personnel or property.
At the top of the photographic gondola assembly was an eye-bolt (1) which connected it to the balloon through the system described above. Directly beneath was a rotator unit (2) which during flight provided a complete rotation of the gondola every 100 minutes to allow panoramic coverage. Below the rotator was located the main pole or main bar (3) from which two ballast containers (4) and a sub-pole (5) were suspended. From the latter hung two boxes: the thermal box (6) containing the control, power and communications equipment, and the DMQ-1 box (7), which contained the photographic package. These poles also supported cabling which electrically interconnected major components of the system.
Ballast containers (4) were box-like cardboard structures designed to hold approximately 600 pounds each of fine steel dust, that could be dumped in flight by electrically controlled valves located in the bottom of each box. The thermal or instruments box (6) was an insulated, moisture resistant cardboard container holding the communication, control, and power components of the system. Outside this box were mounted two antennas: the VHF dipole antenna underneath and HF antenna reel on a bracket attached to the package side. The box contained on the top the battery box composed by four zinc-silver peroxide batteries; a middle space containing 37 plastic water bottles used to maintain temperature inside the package and finally at the bottom the instrument's tray containing the control unit, an HF transmitter, a signal decoder and a VHF tranceiver.
The heart of the system was the DMQ-1 Photographic Reconnaisance Package (7). It was composed by a duplex camera which had two 6-inch lenses located on opposite sides at a 34.5º angle to the horizon. The camera was capable of obtaining about 500 pictures using film of 9 inches square, covering 50 miles on either side of the balloon path. The camera was mounted inside a fiberglass box measuring 36 x 30 x 57 inches lined with six inches of styrofoam for insulation. On the bottom of the box, a photo cell turned on and off the camera according to the illumination of the terrain below. The box also carried a 16 mm gun camera, whose photos indicated balloon's altitude, azimuth and provided a wide-angle view of the ground below which was specially useful for later analysis and overlapping of the images. Mounted on one side of the box were batteries for the operation of the photographic unit and a locator beacon activated by salt water to help find the gondola at sea. To further help with the recovery of the payload, a telescoped pole-like bar was attached to one side of the box which self-extended when hitting the water. The DMQ-1 box descended on a cluster formed by a 12 foot drogue and four 24 foot cargo parachutes (8).
The mission profile was as follows: after launched, the balloon would climb to the preset altitude of about 50.000 ft, and carried by eastward winds it would transit the target zone performing it's photographic task until exiting hostile territory. At that time, a preset timer would turn on an onboard HF beacon which would allow the balloon to be tracked by a series of receiving stations installed across the Pacific Ocean. Once a balloon crossed into the recovery zone and started to transmit, a specially fitted C-119 plane would be sent after it. Once the plane located the balloon, the crew would transmit a special coded signal to terminate the flight and to separate the gondola from the balloon. As the payload parachuted back to earth it would be catched in mid-air by the C-119 and hauled aboard, or if this failed, the package also could be retrieved by that same plane from the water, or recovered later by boat. After rescued, the gondolas were processed on site and the film sent by air to the United States. Imagery obtained was in the hands of the intelligence interpreters an average of 75 hours after recovery.
In all, of the 516 balloon systems launched during the 27 days that endured the campaign, only 44 gondolas were recovered. From these, were obtained useful images only from 40 of them.
Balloon launched on: 2/3/1956 at ~ 22:00 utc
Launch site: Evanton Naval Station, Scotland
Balloon launched by: 1110th Air Support Group
Balloon manufacturer/size/composition: Zero Pressure Balloon General Mills 128TT - 800.000 cuft (2.0 Mils Tailored Tapeless)
Balloon serial number: Serial Nº: 1465
Flight identification number: EVA-91
Landing site: Balloon entered target zone but was never heard of again