Robert Bigelow, 73, CEO of Bigelow Aerospace, appeared in the latest edition of prime time CBS current affairs show 60 Minutes.
But, during the programme, which looked at his work on developing the expandable spacecraft, which inflate in space and could one day change how humans live and work in zero gravity, he made the sensational admission.
He described a UFO encounter his grandparents had on an undisclosed date while driving on a canyon road outside Las Vegas.
He said: "It really sped up and came right into their face and filled up the entire windshield of the car.
"And it took off at a right angle and shot off into the distance."
He told reporter Lara Logan it began an obsession with aliens and is the reason behind his "alien logo" for Bigelow Aerospace.
He said he had since had his own "close encounters", but did not go into details.
The business guru also revealed being a subscriber to a widely held conspiracy theory that the US Government, and others across the globe, know that aliens are here on Earth, and even interact with them, but it is all kept top secret from the public amid fears over the impact it would have on religion and the rule of law.
Old news. The real news is that there are some ET species visiting here that are decidedly hostile. To read more, click here.