##Here is "SpaceData". Swan and Rigby (GLIM Newsletter no 24,1995) state:## ## ## `In 1986 the NASA space shuttle Challenger exploded shortly after ## it was launched. After an investigation it was concluded that this had ## occurred as a result of an `O' ring failure. `O' rings are toroidal ## seals and in the shuttles six are used to prevent hot gases escaping ## and coming into contact with fuel supply lines. ## ## Data had been collected from 23 previous shuttle flights on the ambient ## temperature at the launch and the number of `O' rings, y, out of the six, ## that were damaged during the launch. NASA staff analysed the data to assess ## whether the risk of `O' ring failure damage was related to temperature, ## but it is reported that they excluded the zero responses (ie, none of the ## rings damaged) because they believed them to be uninformative. The resulting ## analysis led them to believe that the risk of damage was independent of ## the ambient temperature at the launch. The temperatures for the 23 previous ## launches ranged from 53 to 81 degreees Fahrenheit while the Challenger ## launch temperature was 31 degrees Fahrenheit (ie, -0.6 degrees Centigrade). ## y Temp 2 53 1 57 1 58 1 63 0 66 0 67 0 67 0 67 0 68 0 69 0 70 0 70 1 70 1 70 0 72 0 73 0 75 2 75 0 76 0 76 0 78 0 79 0 81