abstract:Clean Sky Joint Undertaking is the largest aeronautical research programme ever launched in Europe for the development of breakthrough technologies to significantly increase the environmental performances of airplanes and air transport, resulting in less noisy and more fuel efficient aircraft, hence bringing a key contribution in achieving the Single European Sky environmental objectives.
The sky's the limit." "It's a clean,renewable, highly efficient form of propulsion."
VOA: standard.2010.08.11
To stop this sort of thing happening again Vaios Lappas of the University of Surrey, in England, has designed a system that will remove satellites from orbit at the end of their useful lives and as a bonus will scour part of the skyclean as it does so.