NASA's latest experimental X-plane has received a name.

The United States Air Force has designated the plane, designed in conjunction with Boeing through NASA's Sustainable Flight Demonstrator project as the X-66A.

The X-66A is also the first X-plane designed specifically to help the U.S. achieve the net-zero goal for aviation greenhouse gas emissions, set out in the White House's U.S. Aviation Climate Action Plan, released in 2021.

NASA said in a press release that the X-66A could inform a new generation of sustainable single-aisle aircraft, planes that currently operated as the backbone of passenger-bassed air travel. As a result of their heavy usage, single-aisle aircraft account for around half of aviation greenhouse gas emissions across the globe. This means a sustainable version of such a craft could have a major impact on greenhouse gas emissions. 

"At NASA, our eyes are not just focused on stars but also fixated on the sky. The Sustainable Flight Demonstrator builds on NASA's world-leading efforts in aeronautics as well climate," NASA Administrator Bill Nelson said in the statement. "The X-66A will help shape the future of aviation, a new era where aircraft are greener, cleaner, and quieter and create

new possibilities for the flying public and American industry alike."

NASA has a Funded Space Act Agreement with Boeing for the Sustainable Flight Demonstrator, which will see the space agency make an investment of $425 million over seven years. While NASA also provides the facilities and technical expertise for the project, Boeing and its partners will contribute an estimated $725 million to its funding. 

Together with Boeing, this will see NASA build and fly a full-sized demonstration of the X-66A with extra long thin wings stabilized by diagonal struts, a design called a "Transonic Truss-Braced Wing."