February 03, 2014
Few doubt the merits airships could have in cargo transport, but as the latest developments around Aeros Corp.'s ML866 show, even what looks like a technologically compelling idea has high hurdles to jump between technical maturity and market success.
Aeros faces two primary issues: The collapse of a hangar roof badly damaged its “Dragon Dream” prototype, and the consequences of that mishap are still unclear. And then there is the problem that looms for every prospective airship manufacturer: access to funding. Although the company says there is a lot of interest in its product, it estimates the total investment needed between now and full-swing production at $2 billion.
Aeros CEO Igor Pasternak says the concept will revolutionize airfreight and tourism. He wants to build a 555-ft.-long (169-meter) airship, the ML866, capable of carrying a 66-ton payload at a top speed of 120 kt. over a range of 3,100 nm at an altitude of 12,000 ft. The larger ML868 variant would fly at the same speed and altitude but be 770 ft. long (three times longer than a Boeing 747) and carry 250 tons (roughly twice the payload of a 747F). At $40 million, versus $350 million for a 747, and with an engine that uses commercial-grade diesel rather than jet-grade fuel, the savings would be considerable. The prototype 266-ft-long Dragon Dream has flown (while tethered), and Aeros wants to present it at the Paris air show in 2017.
That is the plan. But Aeros still cannot access its equipment because the U.S. Air Force, which owns the partially collapsed hangar, has not yet granted it clearance. An Aeros official says the company expects to be allowed back in by the end of February. Pasternak says the prototype's fate is insignificant. “There are no more technical challenges to overcome,” he says. “We have solved those. Now it is only management and finance.”
Many companies have spent millions trying to develop commercial airships but none have seen the light of day. Pasternak says Aeros's concept is different because it uses the same technology that provides submarines with buoyancy. Submarines draw in water as ballast to sink and pump it out to rise; the airship uses air instead of water.
With a rigid internal structure made from aluminium and carbon composites, the airship fills and empties internal expansion bladders with helium that is compressed inside large tanks. A partial vacuum surrounds the bladders, which then fill with air from outside the ship, lowering the buoyancy and causing the ship to descend. Releasing the helium back into the airship's main envelope causes the bladders to deflate, lowering the internal pressure of the airship and pushing the air back outside the ship, causing it to rise.
By using air as ballast and keeping the helium in a closed system, the airship requires no additional ballast after cargo has been unloaded, as is the case with traditional airship designs. It also allows it to take off and land vertically—a first for lighter-than-air vehicles.