On the morning of October 27, 1969, a squadron of 18 B-52s — massive bombers with eight turbo engines and 185-foot wingspans — began racing from the western US toward the eastern border of the Soviet Union. The pilots flew for 18 hours without rest, hurtling toward their targets at more than 500 miles per hour. Each plane was loaded with nuclear weapons hundreds of times more powerful than the ones that had obliterated Hiroshima and Nagasaki.
The B-52s, known as Stratofortresses, slowed only once, along the coast of Canada near the polar ice cap. Here, KC-135 planes — essentially 707s filled with jet fuel — carefully approached the bombers. They inched into place for a delicate in-flight connection, transferring thousands of gallons from aircraft to aircraft through a long, thin tube. One unfortunate shift in the wind, or twitch of the controls, and a plane filled with up to 150 tons of fuel could crash into a plane filled with nuclear ordnance.
Read the rest at Wired.com: here.