This is one of the satellite recovery aircraft out of Hickam AFB. They would not land on FFS because (they said) the coral sand would be ingested in the engines when the props reversed. Therefore we had Fiberglas canisters that we put data tapes in from a particularly important track. The can was attached by a nylon rope to a small phosphor bronze grappling hook at the top of the pole shown in the photo. The C-130 had a rig hanging out the rear cargo door that was usually for snagging the parachute of a descending Discoverer capsule while it was still in the air. This time they snagged the data canister hook and went away with the data.
The whole Discoverer project was the subject of a Discovery Channel documentary called "Secret Satellite." The whole project for which FFS played an important (and unheralded) role was covered in detail. The tracking station on Tern Island was installed to provide triangulation between there and the Kaena Point, Oahu, tracking station so the AF C-130's could be vectored to the descending payloads and recovered. It did that a number of times until the whole process became routine later in 1961.