The “bucket drop”, invented by a missionary trying to airdrop gifts to natives in Ecuador, would let warplanes release a swarm of drones and lasso them back.
The warplane of the future is a drone mothership, able to dispatch swarms of small air-launched UAVs for close-up reconnaissance, to act as jammers or decoys, or even to carry out airstrikes. Those drones may be cheap enough to be expendable, but what if you want to recover them?
The Air Force has the answer, using a technique developed by a 1950’s jungle pilot and missionary. Researchers are now experimenting with ways to use his deceptively simple idea—dragging a long tether behind a plane—to let a plane pull its drones back in.
The Perfect Spiral
Nate Saint was a missionary to remote villages in Ecuador. He knew that the best way to prove friendly intentions to new groups of Waodani, a notoriously dangerous people, was to offer gifts, but he wanted a better way of delivering them than haphazard parachute drops. So he developed what he called the “bucket drop.”
The bucket drop involved reeling out a basket loaded with gifts on the end of a line behind the plane, then flying in a circle so the line becomes a spiral with the basket at the center of the circle. Saint then let out more line. Nate’s son Steve Saint, a missionary and pilot like his father whose projects include a flying car, explains what happened next:
“When enough line was extended behind the plane, the end of the line would actually hang motionless in the air. Letting out more line at that point would make the line drop straight down where it could be made to hover just above the ground.”
Nate Saint perfected the bucket drop in California, controlling the line first with a fishing reel and then with the motor from an electric drill. The bucket drop could also make pick-ups. The family dog became the bucket drop’s first passenger, in a safety harness made from a T-shirt.
Nate Saint’s flying pattern was not a matter of calculation but skill and practical experience. Saint was less interested in the theory than in making it work. “Once you get a few principles down, the human brain works out its own system, without the person understanding all that his or her mind is computing,” Steve Saint says.