A billionaire aerospace entrepreneur who has recently worked with Nasa has said he is 'absolutely convinced' that there are alien visitors living on Earth.

Robert Bigelow, whose company Bigelow Aerospace has built expandable space habitats for the ISS, was speaking in an interview with 60 minutes on Sunday.

The conversation focused on working with Nasa before it shifted to Mr Bigelow's reported obsession with aliens, as the mogul revealed he has invested 'millions' into UFO research.

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A billionaire aerospace entrepreneur who has recently worked with Nasa has said he is 'absolutely convinced' that there are alien visitors living on Earth. Robert Bigelow (pictured), speaking in an interview with 60 minutes, said he has spent 'millions' on alien research

BIGELOW'S WORK WITH NASA Billionaire Robert Bigelow runs Bigelow Aerospace, a private space technology company. Last May, Bigelow Aerospace - in partnership with Nasa - inflated an expandable room on the International Space Station (ISS) for the first time. Fully expanded, the module measured four metres (13 ft) long by 3.23 meters (10.6 ft) wide. Astronauts on board the ISS will re-enter the module several times a year throughout the two-year technology demonstration. They will retrieve sensor data and assess conditions inside the unit, including how well it protects against space radiation. Advertisement

Asked whether he believed in aliens, Mr Bigelow responded: 'I'm absolutely convinced. That's all there is to it.'

'There has been and is an existing presence, an ET presence [on Earth].

'I spent millions and millions and millions - I probably spent more as an individual than anybody else in the United States has ever spent on this subject [aliens].'

Mr Bigelow did not specify exactly how much he has spent on this research, and declined to comment on any personal UFO encounters.

Correspondent Lara Logan, who was leading the interview, then asked Mr Bigelow whether he felt it was risky for him to say in public that he believes in aliens.

She asked him whether he worried that people might think he was 'crazy'.

Mr Bigelow responded: 'I don't give a damn. I don't care.'

'It's not gonna make a difference. It's not gonna change the reality of what I know.'

When asked whether he thought future human missions into space would result in alien encounters, he said: 'You don't have to go anywhere. It's just like right under people's noses.'

The entrepreneur's comments come as a surprise considering his company has worked closely with Nasa in the past, which denies any evidence of aliens.

Pictured is a concept image of one of the inflatable space craft that Mr Bigelow's company Bigelow Aerospace has proposed. The mogul did not specify exactly how much he has spent researching aliens, and declined to comment on any personal UFO encounters

WHAT IS THE BIGELOW EXPANDABLE ACTIVITY MODULE? BEAM (CGI pictured) was the first inflatable space habitat ever attached to the International Space Station (ISS) Beam is the first inflatable space habitat to be attached to the International Space Station (ISS). Designed by Nasa and Bigelow Aerospace, Beam launched on the eighth SpaceX Commercial Resupply Service mission, on 8 April 2016. Made up of aluminum and soft fabric, Beam is designed to pack down into a relatively compact 1.7 metres (0.14 ft) long and just under 2.4 metres (7.9 ft) in diameter when stowed for the flight into space. When attached to the station's structure and inflated, it will expand to four metres (13 ft) long by 3.23 meters (10.6 ft) wide. Although this will be the first of these habitats tested on the ISS, Nasa thinks expandables could be a key technology to help humans on the journey to Mars. Advertisement

Last May, Bigelow Aerospace - in partnership with Nasa - inflated an expandable room on the International Space Station (ISS) for the first time.

Nasa's first attempt to inflate an extendable room on the International Space Station had failed the week before due to too much friction.

But their second attempt was a success as Nasa managed to expand and pressurise the add-on room.

The flexible habitat, known as the Bigelow Expandable Activity Module (Beam), fully extended 1.7 metre (5.6 ft).

The expansion followed more than seven hours during which astronaut Jeff Williams released short blasts of air into the pod's walls.

After the expansion was complete, Mr Williams opened eight air tanks inside Beam, pressurising the pod to a level close to the space station's at about one atmosphere.

Last May, Bigelow Aerospace - in partnership with Nasa - inflated an expandable room (pictured) on the International Space Station (ISS) for the first time

Fully expanded, the module is four metres (13 ft) long by 3.23 meters (10.6 ft) wide.

The inflation process may be better described as 'unfolding' since it takes only a small amount of air to bring the pod to full size.

Nasa spokesman, Daniel Huot, said at the time: 'A very successful day today with the expansion of the first expandable human-rated habitat to ever be flown into space.'

The expansion caused a popping sound not unlike that of popcorn as the structure slowly filled out.

Astronauts on board the ISS are expected to re-enter the module several times a year throughout the two-year technology demonstration.

They will retrieve sensor data and assess conditions inside the unit, including how well it protects against space radiation.