Former NASA astronaut Jerry Linenger has revealed there were several instances aboard the International Space Station that made the entire space crew scratch their heads. He referred to the anomalies as "unidentified flying objects," pleading the press not to take him out of context.

In one of Linenger's live interviews, he admitted to seeing several bizarre objects or unexplained sightings during his five-month stay in space. The astronaut recalled how he and his colleagues could only guess and ask among themselves what they saw.

"I saw stuff that made me call my crewmates over and say 'what the heck is that?'," the Linenger said.

Linenger, who is also a retired captain of the U.S Navy Medical Corps, not only stayed at NASA's International Space Station - he also did a stint at the Russian Space Station Mir, which operated from the mid-1980s to 2001.

The former astronaut, along with two Russian crewmates, spent five months at the SS Mir, which at the time was situated 50 million miles about Earth while orbiting the planet 2,000 miles. It was the first time an American astronaut was able to perform a spacewalk from a non-American space station while wearing a foreign space suit.

Linenger's story about seeing unidentified flying objects came with a disclaimer though - he made no mention of seeing aliens, but only things he was unable to distinguish. He said that in space, astronauts often have a hard time making out if an object is somewhere far or just nearby. According to the astronaut, what he saw could be a space junk or some sort, or it could be legit UFO.

"Is it something 100,000 miles away that's the size of a big spacecraft? It's very hard to distinguish that," Linenger explained. "But you would see things and you go 'wow, that's cool - I don't know what that was exactly, but it's not a satellite.'"

Despite all his training, Linenger said that he still feels excited if they spot an object unknown to them. Being in space sure looks like one of the most exciting and remarkable things a human could ever do, but the former astronaut admitted that it's not all fun. In the same interview, he also shared how he and fellow astronauts fought to conquer challenges that could have cost their lives.

Part of this experience was showcased in a Nat Geo special last month, which was the reason why Linenger was in India in September. He was featured in a show that explored the Chandrayaan 2, India's most recent space mission.

While living aboard the Mir, Linenger and his two Russian crewmembers faced the most severe fire ever aboard an orbiting spacecraft, in which they dramatically survived. The Nat Geo special featured the astronaut sharing his death-defying experience and telecast of the Chandrayaan 2 landing on Sept. 7 from the Indian Space Research Organization control room in Bengaluru.