"by letter in Morse code. Kittinger says it was a joke, but Simons didn't take it that way. (Morse code has always been a tough medium for humor.) In his memoir Man High, Simons recalls thinking that "the weird and little understood breakaway phenomenon could be taking hold of Kittinger's mind,...that he...was gripped in this strange reverie and was hellbent on flying on and on without regard for the consequences." Simons compared the breakaway phenomenon to "the deadly raptures of the deep." "Rapture of the deep" is a medical condition"