(FOX NEWS) -- Get ready for close encounters of the "curved" kind.

Former NASA astronaut Leland Melvin tweeted that he saw something "curved, organic looking" floating out of the payload bay during his time on the space shuttle Atlantis.

Fox News reports that he told NASA about it, but the agency told him that what he was seeing was not an extraterrestrial but a piece of ice.

"I have not seen one in space or on the ground but thought I saw something organic/alien like floating out of the payload bay," Melvin tweeted, when asked by the Twitter account UFO Sightings Daily what his thoughts were on extraterrestrial life or if he had ever seen a UFO.

"@AstroKomrade and I called the ground to ask what it could be and it was ice that had broken off of the Freon hoses. Translucent, curved, organic looking??"

Melvin, who played college football at University of Richmond and was drafted by the Detroit Lions in 1985 prior to becoming an astronaut, continued that he was going to say "Houston, we have a problem," but he did not want to be alarmist.

 "I was about to say Houston we have a problem but know everyone spins-up when those words are uttered from a space vehicle. Godspeed??"

It's unclear exactly what Melvin, who has degrees in both Chemistry and Materials Science Engineering, saw, but some on social media wanted to believe that Melvin's sighting was alien in nature, even if he may have been ribbing them.

Fox News has reached out to NASA for a request for comment for this story.

Copyright 2018 WDRB Media and Fox News. All Rights Reserved.