Thank you for publishing Jonathan Penn’s recent Viewpoint “NASA’s Plan Is Not Sustainable,” (AW&ST Dec. 6, p. 74). The pull quote that accompanied it: “Manned missions beyond the Moon are not practical with today’s chemical rocket propulsion. NASA should return to prominence its role as developer of new technologies” sums up the problem. Manned missions beyond the Moon will never be “practical” with chemical rocket propulsion. Chemical rockets already operate within 10% of their ...


You must have an Aviation Week Intelligence Network (AWIN) account or subscribe to this Market Briefing to access "Look Backward To Go Forward".


Current Aviation Week Intelligence Network (AWIN) enterprise and individual members: please go to for access.


Not currently a subscriber? Click on the "Learn More" button below to view subscription offers.

Already registered? here.