A U.S. firm working to develop a supersonic passenger aircraft says the design will lack one thing found in every other such airplane -- windows.

Spike Aerospace of Boston says when its $80 million S-512 aircraft takes off in December 2018, instead of windows it will have massive, high-definition video screens streaming live views of the outside world moving past the aircraft.

Windows bring design and construction constraints particularly significant in supersonic aircraft, Spike Aerospace said. An airplane is stronger without windows, which is why planes carrying military personnel don't have them.

Windows complicate the construction of an aircraft as well, since they must be built to hold in cabin pressure and resist cracking at high speeds and at great altitudes.

While that makes the case for a windowless fuselage with a smooth skin, passengers have long been used to the ability to look out at the passing clouds and the moving landscape below.

Nevertheless, Spike founder Vik Kachoria said, the plan has been for a windowless S-512 since the beginning, thus the decision to provide video screens.

"A few advisers and friends are concerned that there are no windows," Kachoria told WIRED. "But I think that if you give them the screens and give them the visibility, you might be able to get away from that."

The S-512 will hit a top speed of 1,370 mph while carrying as many as 18 passengers, Spike projects.