““Numbers had no rhymes that could cause problems, so it was fine to call out one, two, and three by their proper names. But zero, which was even less likely to create rhyming difficulties, proved to be an irresistible target, and so aviators referred to zeros as “balls.” Wally Schirra, more than most astronauts, could barely contain himself. Throughout the eleven days of the Apollo 7 mission, Wally had taken special pleasure in calling down, “First off, we’ll read off balls,” or “Star difference angle was four balls,” or “Two balls twenty-two, plus four balls six, plus four balls one.” Inevitably, the capcom would follow that lead, since he could hardly say zero when Wally was talking balls. So the voice from the ground would answer the commander: “Okay, all balls minus twenty-six eighty-seven.” Then, finally, a female reporter at a NASA press conference during Apollo 7’s mission raised her hand and said, “I don’t understand about the balls.” All of the male reporters laughed until they cried.””
