NASA news: in-flight foldable wings; highly flexible wings; noise reduction; "green" X-Planes

Addaptative foldable wings
https://www.nasa.gov/feature/nasa-to-test-in-flight-folding-spanwise-adaptive-wing-to-enhance-aircraft-efficiency

Highly flexible wings
https://www.nasa.gov/centers/armstrong/features/highly_flexible_wings_tested.html

Aircraft noise reduction during landing
https://www.nasa.gov/centers/armstrong/feature/NASA_Tech_Reduces_Airframe_Noise.html 

"Green" X-Planes
https://www.nasa.gov/aero/nasa-green-aviation-x-planes