The space agency is planning to offer help to California resident Mr Milner on the first private deep-space mission, a journey to the intriguing yet tiny moon millions of miles away past the asteroid belt, according to New Scientist magazine.
Agreements which have been signed by NASA and Milner’s non-profit Breakthrough Starshot Foundation in September seen by New Scientist reveal the two organisations are working on scientific, technical and financial plans for the ambitious mission.
NASA has already committed more than £54,000 ($70,000) which will be spent on a concept study for a flyby mission.
Breakthrough will not be paid the cash – rather, the figure represents the agency’s own staffing costs on the project.
The teams will team up to work on the project plan and concepts throughout the course of next year.
The icy moons which orbit Saturn and Jupiter have emerged as significant places to look for life.
Europa, one of at least 69 moons orbiting Jupiter, is frequently cited as the best candidate for finding living organisms outside of our own planet, largely because it almost certainly has a huge sub-surface ocean.
The space agency is sufficiently convinced it is planning two multi-billion dollar missions to explore the icy planet in the next decade.
And Titan, the largest of Saturn’s moons, which has a dense, nitrogen-rich atmosphere, is sometimes said to be analagous to Earth billions of years ago.
However, speaking at the 2018 National Geographic Explorers Festival in July, planetary scientist and NASA advisor Carolyn Porco said Enceladus was an even better candidate.
She explained: “I have a bias, and I don’t deny that.
“But it’s not so much an emotional attachment with objects that we study, it’s a point of view based on the evidence.
“We simply know more about Enceladus.
“Really, the Europa people don’t know that much.
“There is a lot of excitement, but it’s speculation at this point. Of course I’d choose Enceladus.”
Like Europa, Enceladus, which measures just 310 miles (500km) across, also has a sub-surface ocean – and a study published in the scientific journal Nature earlier this year identified large organic molecules spewing into space from the its interior as evidence that the moon was a suitable environment for life.
The Breakthrough Initiatives project is aimed at answering the biggest questions about space, including whether there is life on other planets.
Its board includes Mr Milner, as well as Facebook founder Mark Zuckerberg, as well as Professor Stephen Hawking until his death in March.
Listed missions include a solar sail spacecraft to reach nearby stars, developing technology to find Earth-like planets as well as sending out a message for extra-terrestrials.
New Scientist has reported the Breakthrough Foundation, not NASA, would be bankrolling the mission to Enceladus.