The first "A" in NASA has been through a rough patch in recent years, but there is renewed optimism among the agency's aeronautics researchers. Since slumping to an all-time low earlier this decade, NASA's aeronautics program has been restructured and revitalized.

Funding is still well below the billion-dollar levels of the 1990s, but there is a stable stream of money for research across a broad range of technologies, most of it directed toward enabling a revolutionary change in U.S. aviation infrastructure - the Next Generation Air Transportation System, or NextGen.

"In almost 19 years in NASA aeronautics, I've never seen a national thrust toward a new air transport system sustained for so long," says Jaiwon Shin, associate NASA administrator for aeronautics. "A lot of government initiatives tend to fade away, but this is getting stronger and stronger."

Cruise-efficient short-takeoff-and-landing aircraft studied under NASA's subsonic fixed-wing program would increase capacity by making more use of available airport tarmacs.Credit: NASA CONCEPT

NASA's role in NextGen is enshrined in the first U.S. national aeronautics research and development policy, signed by President Bush in December 2006, and the R&D plan approved a year later. Together these establish the principles and objectives for federal investment in aeronautics R&D to 2020.

"Almost everything we are doing, with exception of access to space, is closely aligned with those two documents, and the drivers are NextGen and new vehicles," says Juan Alonso, director of the Fundamental Aeronautics program office within NASA's Aeronautics Research Mission Directorate.

"Never in the history of the U.S. have we ever had an aeronautics policy signed by the President," says Shin. "It's only R&D - we don't have an industrial or manufacturing policy - but for NASA aeronautics that is all of it. The policy clearly identifies what the nation is expecting, and it has the lasting power of an executive order."

While the policy directs NASA to stay focused on fundamental research, and makes it the steward of core U.S. aeronautics competencies, it is NextGen that gives aeronautics protection within NASA, says Shin. "NASA's role in NextGen is to address fundamental research questions and enable a revolutionary system. If it's to be truly green, it requires a lot of new technology and we have a long way to go."

NextGen, and the R&D policy and plan, have given NASA's aeronautics research new relevancy and energy. "We have never before had that unified community - Congress, White House, industry and academia - all saying aeronautics is important," says Shin. "There was a lot of criticism that aeronautics was a sunset industry. Now it's on the verge of a renaissance."

NASA's contributions to aircraft design are overshadowed by the achievements of its predecessor, the National Advisory Committee for Aeronautics (NACA), which in the post-World War II years led a massive U.S. effort to push back the boundaries of powered flight with a storied series of X-planes. Even Shin, asked to name NASA's greatest achievements in aeronautics, thinks first of NACA's landmark work in defining airfoils.

But the greatest X-plane of them all, the hypersonic X-15, flew almost a year after NACA became NASA and spaceflight took over from aeronautics as the agency's priority. In the years that followed, NASA developed the supercritical wing and winglets, both widely used today in civil aircraft, as well as pioneering digital fly-by-wire.