During the Cold War, the US and the Soviets had an ongoing game of tag taking place under the Arctic Ice Cap. Among the better-known technologies employed in this chase, both sides often built "research stations" on the arctic ice floes. Though there was a potential for real science to take place in such locales, the purpose of these ramshackle huts was just to house hydrophones that would track submarines ranging the Arctic Sea. A problem arose, however, in manning these stations: they were beyond the limited range of the period's helicopters, too far into the floe for icebreakers, and in areas that are inhospitable to landing airplanes.
The only practical solution was to deliver personnel from an airplane without stopping, which meant that anyone who pulled arctic-listening-post duty had to parachute onto the ice. When it came time to bring them back home, their extraction was very much like their dramatic parachute entrance, only in reverse.
The idea of fly-by retrievals was first explored during World War II. American and British soldiers would equip with a full harness, and connect it to a cable which was strung to the top of a tall pole. The soldier would then stand between two such poles, and a specially fitted aircraft (usually a C-47 Skytrain) swooped in low, and hooked the cable, lifting the soldier from the ground. Though the system worked, it was generally cumbersome and difficult to set up.
Experiments for an improved system began in 1950 under Robert Edison Fulton, Jr. He was an inventor for the CIA, and had taught himself to pilot a plane. He tried to devise a way to pick up a weight from the ground that would be easier to set up than the method employed in the war. He tested his various methods with his own plane. By 1958 Fulton had developed a reliable method for snaring such a weight, and developed a package containing all that a person would need to use it.
The Fulton surface-to-air recovery system, or more commonly called "Skyhook", could be dropped from a plane to any target, where a single person with proper training could outfit a body or cargo for pickup. The package consisted of: a harness for cargo or person; a 500-foot, high-strength, braided nylon line; a portable helium bottle; and a dirigible-shaped balloon.
The person would climb into the harness, and connect it to the balloon with the nylon wire. With the simple pull of a ripcord, the balloon would inflate from the helium bottle, and would thus rise. The line was marked with flags or lights to help the airplane find the target.
The airplane had to be fitted with a pair of tubular horns on the nose. In practice, the plane aimed right at a marker on the line, and the horns would catch the line. A mechanism would snap closed when the line was caught, releasing the balloon and anchoring the line to the aircraft. As the target was lifted from the ground, the line streamed back into the aircraft's wake. The crew in the back of the plane would use a long hook to catch the line, and the target would then be winched into the bay.
The first live test was conducted with a pig as the target. Due to some stability issues, the pig spun in the 125 mph wind, and arrived on the plane dizzy and discombobulated. It recovered, however, and promptly attacked the crew.
Later in 1958, Staff Sergeant Levi W. Woods became the first human to experience the Skyhook system. After the initial snap of being pulled from the ground, he rose slowly into the air until he was behind the aircraft. During the ascent he extended his arms and legs, thereby thwarting the oscillations that had plagued the pig. Six minutes after the process began, Staff Sgt. Woods was safely aboard the P2V Neptune. Following this successful test, the Skyhook was assigned its first mission in 1961: Operation Coldfeet.
One of the Soviet Floe Stations-- NP 9-- had to be abandoned in May of 1961. The runway that was used to supply the station had cracked and was unusable. The US direly wanted to take a peek at the Soviet's toys, and in planning, it seemed the Skyhook would be the ideal means of deploying. Unfortunately, by the time the operatives were trained and the kinks in cold-weather deployment were worked out, NP 9 was out of range. As luck would have it, in March 1962 another Soviet Floe Station, this time NP 8, was abandoned when an ice ridge destroyed the runway. After weeks of searching, NP 8 was found. US spies were loaded onto an airplane and flown to the remote arctic region, where they parachuted onto the ice. After gathering their intelligence, pick up was a little tricky. The weather had degraded to nearly white-out conditions, and the surface winds were near 30 knots. The first pick-up went well, but on the second the balloon was launched, and immediately caught in the wind. The soldier was dragged across the ice. As he tried to regain his breath, the plane hooked the line. He swung wildly in the void, unable to see, and whipped by the cold wind. To the credit of the Skyhook's design, he managed to orient himself, and was pulled safely aboard.
Despite the adversarial weather, everyone came back safely, and what better accolade could there be? The Office of Naval Research approved the Skyhook for general use.
The Skyhook was rendered obsolete with the arrival of longer-range helicopters that could make a pick up in a secluded location faster and with less bustle. In 1996, the US military ceased maintaining Skyhook training and readiness. It's a shame, because damn, what a ride.