A tribute to the men and women who put their lives on the line in order to get a foothold in space, sometimes with disastrous results.
Troubleshooting in space can be a matter of life and death, from deep-space collisions to deadly chemical leaks; astronauts are forced to innovate to survive.
Space travel is fraught with nature's dangers. Lightning nearly scuttles Apollo 12, solar flares threaten the space station, and a cold snap leads to the Challenger disaster.
Launching a spacecraft is hard, but U.S. and Soviet disasters show that getting safely back to Earth is even harder; engineers face huge challenges for a safe splashdown.
The U.S. and Soviet Union's early space programs face incredible engineering challenges, but catastrophic losses are converted into victories of engineering and the human spirit.