Stratolaunch, the largest plane ever built, took its first flight Saturday out of California's Mojave Air & Space Port, spokesperson Andrea Courtney confirmed in a statement to USA TODAY.
"Achieving a maximum speed of 189 miles per hour, the plane flew for 2.5 hours over the Mojave Desert at altitudes up to 17,000 feet," the statement read. "As part of the initial flight, the pilots evaluated aircraft performance and handling qualities before landing successfully back at the Mojave Air and Space Port."
The plane is the largest in the world based on wingspan — measuring 385 feet — which is longer than a standard NFL football field. It also weighs 500,000 pounds, more than the biggest Boeing 747, and boasts six 747 engines.
Stratolaunch Systems, the aeronautics company founded by late Microsoft co-founder Paul Allen, has been working on the project since 2011 as part of a plan to make travel to low Earth orbit more accessible.
"Opening up access to (low Earth orbit) will deliver many benefits," Allen wrote on LinkedIn in 2016. "For example, we could deploy more satellites that would enable better understanding of why our weather patterns are changing and help increase agricultural productivity. And, we could study atmospheric chemistry more closely to better study and mitigate climate change."