A prototype of the massive solar-powered drone Google Inc. plans to build as a platform for delivering Internet service from the sky was destroyed in a crash at a New Mexico test site.

The unmanned Solara 50 fell to the ground shortly after takeoff on May 1 and the U.S. National Transportation Safety Board is investigating, Keith Holloway, an agency spokesman, said in an interview. The accident occurred at a private airstrip east of Albuquerque and no one was injured, he said.

The crash is a setback for Google’s high-altitude vision of how to bring Internet access to areas of the world without sufficient infrastructure on the ground. 

Titan Aerospace, the company Google bought last year for undisclosed terms, built the drone, which its promotional material says has a wingspan of 50 meters (164 feet). It is supposed to fly above the weather, where it could then beam Internet signals to earth as if it was a satellite.

“Although our prototype plane went down during a recent test, we remain optimistic about the potential of solar-powered planes to help deliver connectivity,” Courtney Hohne, a spokeswoman for Mountain View, California-based Google, said in an interview. “Part of building a new technology is overcoming hurdles along the way.”

The company is in a race with Facebook Inc., which also attempted to buy Titan, a company headed by former Microsoft Corp. executive Vern Raburn. Facebook instead acquired U.K.- based Ascenta, which is designing its own high-altitude drones, for $20 million.

The acquisitions are part of a broader strategy by the two Internet companies of pushing technology in areas such as robotics and mobile phones in hopes of pioneering new markets.

Thin Wings

The upper surface of the wing on Google’s Solara 50 is covered in solar cells to generate power, according to company data. It’s designed with batteries that store electricity so it can continue flying at night and stay aloft for five years.

The drone Google intends to use in providing Internet service will be larger and capable of carrying heavier payloads than the model that crashed.

Titan has also flown a smaller version, the Solara 10, according to a company video. The planes are built with a thin fuselage and relatively long, curving wings that allow them to fly through thin air as high as 65,000 feet (19,812 meters). For comparison, airlines mostly cruise between 30,000 feet and 40,000 feet.

While the Google Solara crash wasn’t a threat to people on the ground, U.S. regulations require the NTSB to investigate accidents of drones weighing more than 300 pounds, Holloway said. The agency hasn’t set a date for when it will release a more detailed report on the accident and its cause, he said.

FAA Interest

The NTSB hasn’t yet posted a preliminary report about the incident on its website listing aviation accidents under investigation.

The U.S. Federal Aviation Administration, which regulates aviation and had registered Google’s aircraft, is also monitoring the investigation, according to an agency statement.

Google’s Titan subsidiary had registered three Solara 50 drones with the FAA, including the one that crashed. The FAA allows companies to register experimental and test aircraft, and also has a process to approve unmanned flights by manufacturers.