(This planet is the cradle of human reason, but one cannot live in a cradle forever.) —Konstantin Tsiolkovsky, 1911 There can be no thought of finishing [work on rockets], for “aiming at the stars,” both literally and figuratively, is a problem to occupy generations, so that no matter how much progress one makes, there is always the thrill of just beginning. —Robert Goddard, 1932 EPILOGUE On August 6, 2012, the Mars rover Curiosity approached the surface of Mars after a nine-month journey through interplanetary space. At NASA’s Jet Propulsion Laboratory in Pasadena, California, a room full of flight controllers and engineers bit their nails and paced the floor while Curiosity went through its complicated and daring entry sequence, nicknamed the “seven minutes of terror.” Flight control erupted in emotion when the signal indicated that Curiosity was safe on Mars. A record number of people (3.2 million) watched the landing live online, so many that the server became overloaded and temporarily shut down.
