A former Captain in the United States Navy Medical Corps, Linenger spent a total of 132 days aboard the Russian space station Mir as part of the STS-81 mission in 1997.

In a recent interview, he recalled some of the strange things that he saw during that time.

"Well I'm going to stick my neck out, but how many people think I saw a UFO when I was up there ?" he said. "Well I did, I saw things in the true sense of the word, unidentified flying objects - don't take me out of context there - no aliens."

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