the origins of the halo technique date back to 1960 when the united states air force began conducting experiments that followed earlier work by colonel john stapp in the late 1940s through early 1950s on survivability for pilots ejecting at high altitude. stapp, a research biophysicist and medical doctor, used himself in rocket sled tests to study the effects of very high g-forces. stapp also solved many of the problems of high-altitude flight in his earliest work for the air force and subjected himself to exposure to altitudes of up to . he later helped develop pressure suits and ejection seats, which have been used in jets ever since. as part of the experiments, on august 16, 1960, colonel joseph kittinger performed the first high-altitude jump at above the earth's surface. kittinger's friend and united states naval parachute test jumper joe crotwell was also among the consultants and test jumpers of the original program. the first time the technique was used for combat was during the vietnam war in laos by members of macv-sog. seal team six of the united states navy expanded the halo technique to include delivery of boats and other large items.