Roamy here. You saw the post title and thought Apollo 13, right? Let me tell you a NASA story you may not have heard.
The Apollo-Soyuz Test Project was an idea floated after Apollo 11, for peace in space between the Americans and the Soviets. It flew in July 1975, with Tom Stafford, Vance Brand, and Deke Slayton for the American crew, Alexei Leonov and Valeri Kubasov for the Soviet crew.
Deke Slayton was the last of the original Mercury 7 astronauts to finally fly in space. A heart rhythm problem had grounded him earlier. Tom Stafford had flown on a couple of Gemini flights and flew this >< close to the moon on Apollo 10. Stafford also served as a pallbearer for the Soyuz 11 crew (story for another post), so the Soviet cosmonauts knew him pretty well. And you should know that Alexei Leonov was the first man to walk in space.
The mission went as smoothly as could be expected – the two launches only a few hours apart, docking without a hitch, pictures of the historic handshake in space. There were some experiments performed in space that would be the last ones until the Space Shuttle flew six years later.
Where everything started to go wrong was during re-entry. A switch for the hypergolic reaction control system (steering) wasn’t thrown, so the lines stayed open. When the Apollo capsule dropped below a certain altitude, a vent automatically opened to allow in fresh air, but it was close enough to the guidance system to let in a cloud of highly poisonous nitrogen tetroxide. Stafford wrote in his book We Have Capture that they had a very hard landing and ended up upside-down. He had to unbuckle to get to the oxygen masks, they were all coughing, and Vance Brand passed out from the fumes. Once onboard the USS New Orleans, the usual welcoming celebration was cut short and the crew hustled to sick bay. The ship sailed immediately to Hawaii, “the whole ship shaking as they put the power to it.” All three astronauts had edema in their lungs (chemically-induced pneumonia) and needed two weeks to recover enough to fly back to the States.
On a good note, X-rays of Deke Slayton’s lungs showed a precancerous lesion (not accident-related), so it was caught in time. They were very lucky to have survived the hypergol exposure. It was the last spaceflight for Stafford, Slayton, and Leonov. Kubasov later commanded the Soyuz 36 mission, and Brand commanded three Shuttle missions. One interesting note: Deke Slayton was the oldest astronaut to have flown at the time of Apollo-Soyuz, and Vance Brand became the oldest astronaut when he flew STS-35. (John Glenn is the current record-holder, and I think that will stand for a while.) I am personally indebted to Vance Brand for a materials experiment flown on STS-5 and the ASTRO-1 telescopes flown on STS-35.