Gus Grissom tried not to give much thought to the fact that the rocket he was riding to space was built to kill people. But the terrible V-2 would become the beautiful Redstone, and American Astronauts - manifestly the good guys - would ride them into space. TIME’s Jeffrey Kluger takes you through the Liberty Bell 7 mission and the events that make it one of the most harrowing space missions of all time.