Importantly for Stratolaunch though the company was able to conduct a first test flight (as reported in The Verge) which saw their massive new plane successfully fly the plane for a total journey of 150 minutes - and importantly, safely land the plane. Pacific Time, according to a release of Stratolaunch.
Stratolaunch calls the plane "the world's largest all-composite aircraft".
The Mojave Air & Space Port is located in California (the "Golden State") and is the first site which is licensed to horizontally launch reusable spacecraft from.
It's a novel idea which has already seen the company sign up its first customer in Northrop Grumman, which plans to use Stratolaunch to send its Pegasus XL rocket into space.
The world's biggest airplane took flight on Saturday.
The impressive machine spent two and a half hours in the air during the test flight, reaching speeds of 189 mph (304 km/h), not almost as much as the world's fastest supercars.
The centre wing of the plane can hold up to 500,000 pounds in weight.
Stratolaunch was established in 2011 by Microsoft cofounder Paul Allen, who died in October previous year.
The aircraft has a world-record wingspan of 385 feet, and is 238 feet long. Jody Allen, chair of Vulcan Inc. and Trustee of the Paul G. Allen Trust said, 'We all know Paul would have been proud to witness today's historic achievement'. "The aircraft is a remarkable engineering achievement and we congratulate everyone involved". Dozens of photographers, industry bloggers and aerospace enthusiasts gathered this week to glimpse the unique twin-fuselage plane.