4 New 'Blimp' Designs Bring Return of the Airship

"Always on the verge of a seeming comeback, airships are back in the spotlight, touting new technologies. The Defense Advanced Research Project Agency recently announced funding for an innovative, ballast-free airship technology created by Aeros Aero­nautical Systems, based outside Los Angeles. The Aeroscraft ML866's potentially revolutionary Control of Static Heaviness system compresses and decompresses helium in the 210-ft.-long envelope, changing this proposed sky yacht's buoyancy during takeoff and landings, Aeros says."

http://www.popularmechanics.com/science/air_space/4242974.html