Relatively poorly known is the VB-series of guided bombs developed by Douglas for the US Army Air Force during WWII. The VB-9 was a radar guided bomb; the radar transmitter was located in an aircraft (not necessarily the bomber), the receiver was located in the bombs nose, and the radar image would be sent to the launch aircraft, where the bombardier would view the image and send radio commands back to the bomb to guide it to its target. Radar was chosen over TV due to its all-weather capability.
The VB-9 used a 1000-pound bomb with cruciform wings. The wings were for guidance, not lift; it fell on a largely ballistic path rather than gliding to the target.
The drawing below show a test version of a self-guided ROC-1. In this case, the seeker was a photoelectric cell, and the target on the ground was brightly illuminated. The image sent from the bomb to the bombardier would thus be similar to what would be sent if radar was used; it would just be a while lot cheaper. Even so, with complete control over the illumination of the target, tests were stil inconclusive.Additionally, there was so much clutter in the radar image that it and the resulting guidance were almost completely useless. As a result, the VB-9 “ROC-1” was cancelled in early 1945.
Length overall: 9.98 inches
Wingspan: 77 inches
Weight with payload: 1300 lbs
