Stratolaunch Roc Plane the Size of a Football Field Takes Longest Flight

Private aerospace firm Stratolaunch conducted a second test flight of its hulking Roc carrier jet on Thursday.

Footage of takeoff was posted online by the company's official Twitter account, and can be seen below.

The bizarre-looking plane has the largest wingspan of any aircraft ever. Its recognizable design features two fuselages, giving Roc the appearance of two normal-sized jets joined together at the wing.

Roc's total wingspan is 384 feet—much longer than that of the Airbus A380, the world's biggest passenger jet, which has a wingspan of around 262 feet.

It also dwarfs the wingspan of the enormous Antonov An-225 transport aircraft, touted as the biggest military transport aircraft in the world by Military Today. That has a wingspan of 290 feet.

Put another way, the Roc's wingspan is longer than an NFL football field, which measures 360 feet, end to end.

If the Roc was put on its side so that the wings were vertical, the plane would be nearly as tall as the Great Pyramid of Giza.

Roc is powered by six Boeing 747 engines that allow it to carry more than 1,300,000 lb of weight at takeoff. Its center wing can support up to 500,000 lb.

It is designed to carry other aircraft into the air and then release them for a mid-air launch.

Stratolaunch was founded in 2011 by the late Microsoft co-founder Paul Allen. At the time, Allen envisioned Roc as a plane that would be able to launch satellites into space from mid-air.

However, Stratolaunch changed hands in 2019, and Roc has been repurposed to carry hypersonic vehicles—or vehicles that can travel more than five times the speed of sound.

Hypersonic technology is something the U.S. military has shown interest in, and Stratolaunch could help with U.S. defense development in that area, the company says.

David Millman, chief technology officer for Stratolaunch, told Geekwire: "That's exactly one of the areas that we're looking at: how can we help the Department of Defense in mitigating risks for all their extensive flight testing."

Alongside Roc, Stratolaunch is also developing Talon-A, a testbed for hypersonic research and experiments.

In an October 2020 press release, technology company Draper, which has partnered with Stratolaunch, said Talon-A "is designed for use by government, including the Department of Defense, the commercial sector and academia, which will contract for payload capacity for space or earth applications."

Thursday's flight saw Roc take off from the Mojave Air and Space Port in California at 10:28 a.m. EDT. It reached an altitude of 14,000 feet and a top speed of just under 200 mph, according to Space.com. It flew for more than three hours.

Roc made its first ever flight in April 2019 from the same spaceport.