Recently, an aircraft industry reporter was being escorted around the Lockheed Skunk Works (a facility that has, since World War II, been a site for development of secret aircraft projects). The reporter noted something, largely hidden behind a temporary wall in a hanger, and recognized it as the not-so-secret "P-971." This is the code word for the latest effort to develop an aerodynamic blimp (or airship) as a cheaper way to transport cargo by air. The idea has been around for over three decades, and the concept is simple. An aerodynamic blimp is a helium filled aircraft, with a rigid, but lightweight, shell that is aerodynamic (like an airplane wing.) Thus the aerodynamic blimp takes off and flies like an aircraft, gaining additional lifting power in the process, and able to carry heavy and bulky cargoes using low power (and low fuel consumption) engines. All past efforts to make aerodynamic blimps practical have failed because these aircraft are still lighter than air vehicles, and difficult to handle on the ground or whenever it's windy. They are also large and bulky compared to conventional transports.
Financing these latest efforts are Lockheed (P-971) and DARPA (the Defense Advanced Research Projects Agency), which is funding WALRUS. Lockheed believes that advances in materials and automated flight controls make these aerodynamic blimps practical. But, so far, no one has created a commercially viable example of the concept. This is why WALRUS is being cancelled. But DARPA is still interested, and is keeping an eye on P-971.
This is an example of an evolutionary technology. Engineers (and some tech savvy historians) understand how some of these crazy ideas eventually do become economically practical. The problem is figuring out when the needed technologies will all mature and make it possible to build workable, and commercially self-sustaining, products. Get involved too early, and you spend a lot of money, with little return. Get in too late, and you just end up another competitor in a crowded market. Lockheed seems to sense that the sweet spot (the time when the first commercially viable products can be built, and the highest profit margins are available) is on the horizon, and they may be able to get there first with P-971.