Earlier this fall, a California startup embarked on a test flight of its new airship.

Flown with the help of 13 helium bags, a dozen electric motors and four fin rudders, "Pathfinder 1" exited its hangar at Moffett Field near Palo Alto in early November. After years of development, it's beginning the next phase of its lifecycle: outdoor flight testing.

Far larger than the biggest passenger jets

The airship measures a whopping 408 feet in length. For context, an A380 jet (shown below) is 239 feet long.

Backed by Google co-founder Sergey Brin, it's the product of Silicon Valley-based LTA Research. LTA is an acronym for "lighter than air," which is what Pathfinder 1 is: Pilots inside a gondola control the airship's motors and rudders with an electronics-controlled fly-by-wire system.

The airship received a special FAA airworthiness certification earlier this year, allowing LTA to conduct flight testing of the massive flying ship.

See an airship, and your thoughts might turn to the earlier days of aviation; back then, the craft were once considered an early rival to airplanes and used by the U.S. Navy, as noted by the Smithsonian's National Air & Space Museum.

The age of the rigid airship "Zeppelins" also included the ill-fated, 800-foot-long Hindenburg, which killed dozens as it caught fire while docking in New Jersey in 1937.

In recent years, companies like Goodyear have flown their own version of an airship, though not nearly as big as LTA's Pathfinder 1.