No astronauts ever wanted a mission more than Tom Stafford and Gene Cernan wanted Gemini 9 in the spring of 1966. And no astronauts ever wanted one less either.
The mission itself was a first-rate assignment, one that included a rendezvous and docking with an Agena target vehicle as well as an extended spacewalk for Cernan. And it wouldn’t be just any spacewalk; Cernan would be wearing what amounted to an orbital jet pack, allowing him to zip around at the end of a long tether with a maneuverability no American astronaut or Soviet cosmonaut had ever enjoyed before.
The problem was, the mission was never supposed to belong to Stafford and Cernan at all. It had come to them just a few months before, only after a terrible tragedy had struck NASA. Stafford and Cernan would resolve to fly it well—but they knew they could never fly it with unalloyed joy.
As it happened, tragedy appeared ready to strike again. This time it took aim at Cernan, and this time it threatened the space agency with something it had never experienced before: the death of an astronaut during a flight—and a death of the worst imaginable kind.
Episode 5 of Countdown: The 10 Most Harrowing Space Missions of All Time, tells the tale of Gemini 9, and of the quick thinking and steady nerves of two astronauts who were determined that disaster would not strike the same mission twice.
More Must-Reads from TIME
- Donald Trump Is TIME's 2024 Person of the Year
- Why We Chose Trump as Person of the Year
- Is Intermittent Fasting Good or Bad for You?
- The 100 Must-Read Books of 2024
- The 20 Best Christmas TV Episodes
- Column: If Optimism Feels Ridiculous Now, Try Hope
- The Future of Climate Action Is Trade Policy
- Merle Bombardieri Is Helping People Make the Baby Decision
Write to Jeffrey Kluger at jeffrey.kluger@time.com