bunch of really interesting ways. the dash 80 first evolved on the military side into something called the stratolifter, which is such a late '50s, early '60s name, right? the c-135 stratolifter. it is still to this day a workhorse transport plane for the united states air force. in the mid-'60s, 1965, boeing started making a special variant of the c-135 stratolifter. and the special variant they made -- cool name alert -- it was called the constant phoenix. and that variant of that plane was specially modified to fly around the world, taking samples of the air, sniffing the atmosphere for signs that someone somewhere on earth had set off a nuclear explosion. constant phoenix. that variant of the stratolifter went into use for the first time in 1965, the height of the terror of the cold war.