No program better symbolizes human mastery of machines than does the space shuttle. But the breakups of EM Challenger /EM and EM Columbia revealed the program is tragically flawed. Based on the James Chiles’s book EM Inviting Disaster , we look at the 1930 crash of the EM R-101 /EM , a dirigible which, much like Challenger, was rushed into flight and met with disaster, and the EM Hindenburg /EM , whose 1937 explosion ended dreams of commercial flights for an entire industry. Will the shuttle program go the way of the dirigible?