“It’s like spaghetti,” Dr. Caplice said. “He’s going to throw it on the wall and see if it sticks.”

Dirigibles have long dealt with a perception problem — nobody wants to get on the next Hindenburg. The sell has been much easier among scientists, who understand that these ships run on nonflammable helium, unlike the Hindenburg, which immolated when its hydrogen tanks exploded while docking in Lakehurst, N.J., in 1937.

Airships have found their most reliable use not in carrying people or cargo, but instead as slow-moving billboards in the sky, notably for Goodyear and MetLife. Interest was also keen from the military, but that has cooled in recent years in the face of cutbacks. Representative Brad Sherman, a California Democrat and a senior member of the House Foreign Affairs Committee, said the Air Force leadership was being shortsighted.

“It’s natural for the military to underinvest in research and logistics,” Mr. Sherman said. “It’s less sexy. The Air Force wants a fighter plane to shoot down a Chinese plane invented 10 years from now and deployed 20 years from now. The truth is logistics is terribly important, for both military and civilian purposes.”

Mr. Sherman cited two potential uses for the military: being able to drop 100 soldiers and their equipment in any open field, and plastering an American flag over the Aeroscraft to serve as a valuable advertisement when it is delivering humanitarian aid to foreign countries.

Though much of the Aeroscraft’s development costs have been covered by government military contracts, Mr. Pasternak has begun to turn more toward the private sector. He says he is convinced there is value in being able to deliver wind turbines to remote areas, something no air vessel can do. Or in getting overseas goods produced in November to American markets for the holiday season, something no cargo ship can move quickly enough to do.

But Richard Aboulafia, a cargo industry and transportation analyst, said the private sector market for an airship like the Aeroscraft “is a problematic one.”

Mr. Aboulafia said there were three hurdles to overcome: the difficulty in making a new market entrance in air transportation, Cold War-era Russian planes that can be leased inexpensively and the fact that exotic cargo is often a one-way trip, which raises costs.