It’s been in planning for over a decade, and now NASA ’s supersonic X-plane will finally begin construction.

NASA has awarded a $247.5 million (£175.7 million) contract to Lockheed Martin Aeronautics Company to build the X-plane by the end of 2021.

Taiwan Shin, NASA’s associate administrator for aeronautics, said: “It is super exciting to be back designing and flying X-planes at this scale.

“Our long tradition of solving the technical barriers of supersonic flight to benefit everyone continues.”

NASA’s supersonic X-plane will finally begin construction (
Image:
Lockheed Martin)

Currently, supersonic aircraft are prohibited from flying over land due to the deafening sound levels produced by their sonic booms.

But the key goal for the project is to develop a supersonic aircraft with sonic booms that it could be used for commercial flights in the near future.

To reduce the sound produced, the X-plane has a uniquely-shaped hull that generates supersonic shockwaves.

An artist's impression of the X-plane (
Image:
Lockheed Martin)

While shockwaves from a conventional aircraft design meet as they expand away from the airplane’s nose and tail, the X-plane’s shape sends those shockwaves away from the aircraft in a way that prevents them from coming together and producing loud booms.

Instead, the much weaker shockwaves reach the ground still separated, and are heard as a quick series of soft thumps.

The X-plane will be 94 feet long with a wingspan of 29.5 feet and have a fully-fueled takeoff weight of 32,300 pounds.

A single pilot will be in the cockpit - one of whom will be Jim Less, a NASA pilot (
Image:
NASA / Maria Werries)

It will have a cruising altitude of 55,000 feet at speeds of 940 miles/hour, and a top speed of I990 miles/hour.

A single pilot will be in the cockpit - one of whom will be Jim Less, a NASA pilot.

Mr Less said: “A supersonic manned X-plane! This is probably going to be a once-in-a-lifetime opportunity for me. We’re all pretty excited.”

Construction is expected to be completed by 2021, with commercial flights expected to take place by 2025.