persuaded him to buy her sandwiches by telling him he could eat them at her place, but then, after he bought them, saying they actually could not eat together because another man was coming over. Later on that same evening, Ann returned to the bar to take Feynman to her place. Feynman states at the end of the chapter that this behaviour was not typical of him: "So it worked even with an ordinary girl! But no matter how effective the lesson was, I never really used it after that. I didn't enjoy doing it that way. But it was interesting to know that things worked much differently from how I was brought up." Challenger disaster Feynman played an important role on the Presidential Rogers Commission, which investigated the 1986 Challenger disaster. He had been reluctant to participate, but was persuaded by advice from his wife. Feynman clashed several times with commission chairman William P. Rogers. During a break in one hearing, Rogers told commission member Neil Armstrong, "Feynman is becoming a pain in the ass." During a televised hearing, Feynman demonstrated that the material used in the shuttle's O-rings became less resilient in cold weather by compressing a sample of the material in a clamp and immersing it in ice-cold water. The commission ultimately determined that the disaster was caused by the primary O-ring not properly sealing in unusually cold weather at Cape Canaveral. Feynman devoted the latter half of his 1988 book What Do You Care What Other People Think? to his experience on the Rogers Commission, straying from his usual convention of brief, light-hearted anecdotes to deliver an extended and sober narrative. Feynman's account reveals a disconnect between NASA's engineers and executives that was far more striking than he expected. His interviews of NASA's high-ranking managers revealed startling misunderstandings of elementary concepts. For instance, NASA managers claimed that there was a 1 in 100,000 probability of a catastrophic failure aboard the Shuttle, but Feynman discovered that NASA's own engineers estimated the probability of a catastrophe at closer to 1 in 200. He concluded that NASA management's estimate of the reliability of the Space Shuttle was unrealistic, and he was particularly angered that NASA used it to recruit Christa McAuliffe into the Teacher-in-Space program. He warned in his appendix to the commission's report (which was included only after he threatened not to sign the report), "For a successful