The world’s biggest airplane is staying on track to take to the air for the first time by the end of this year, according to Paul Allen, who made billions of dollars as Microsoft’s co-founder and is now spending millions of dollars on the Stratolaunch air-launch system.

Allen provided an update on Stratolaunch and dropped hints about future space endeavors today during an interview at the University of Washington’s Paul G. Allen Center for Computer Science & Engineering, where professors, students and VIPs celebrated Allen’s $40 million gift to UW’s 50-year-old computer science program,

Most of the interview was devoted to Allen’s reflections on how computer technology has changed since he and his high-school friends took advantage of the UW’s computer lab on the sly in 1971. But the billionaire entrepreneur and philanthropist also was clear about his commitment to the Stratolaunch project, which was unveiled back in 2011.

The key to the launch system is a twin-fuselage plane that incorporates parts from two Boeing 747 jets, with a wingspan that stretches out to a record-setting 385 feet. That’s twice the wingspan of a 747, and more than the length of a football field.

“It is … I can’t even figure out the right adjective. Is it ‘ginormous’? I don’t know,” Allen joked. “It’s pretty darn big. The tail is 50 feet high, just the tail. It’s probably the biggest carbon-composite vehicle ever constructed.”

Scaled Composites, the company that built the SpaceShipOne rocket plane with Allen’s backing more than a decade ago, is assembling the Stratolaunch plane inside a 103,000-square-foot hangar at California’s Mojave Air and Space Port. “The plane is really coming along,” Allen said. “We’re going to hopefully be flying it later this year.”

After flight testing, Stratolaunch is destined to serve as an air-launch platform. The six-engine plane should be powerful enough to carry rockets weighing hundreds of thousands of pounds up to a high altitude, then drop those rockets to launch payloads into orbit from midair. Orbital ATK has agreed to build the rockets, and there could be other launch partners as well.

“One of the unique things about Stratolaunch is that it doesn’t require a fixed launch pad,” Allen explained. “You can imagine systems that are very flexible for missions where you want to launch satellites at different orbits, from different angles. … Then there’s the fact that just doing an air launch gives you an advantage of probably 30 percent in performance.”

Visited @Stratolaunch & proud of amazing work my team is doing to bring world's largest composite aircraft to life https://t.co/jJX9oJj4zX pic.twitter.com/PBPNczH19c — Paul Allen (@PaulGAllen) December 19, 2016

Stratolaunch was created to help fill a rising need for launch capacity.

“Now you’re seeing so many more applications of satellites to watch things happening on the ground,” Allen explained. “In my case, I’m interested in things like watching illegal fishing, watching the changes to our biosphere from orbit. … The demand for these small satellites is increasing dramatically. Who’s going to capture the market? We have some unique approaches.”

Some tech billionaires, such as Jeff Bezos (the founder of Amazon and Blue Origin) and Elon Musk (the CEO of SpaceX and Tesla), have already been in on high-profile meetings with President Donald Trump to lay out their agenda for innovation. So far, Allen has kept a lower profile – but the self-described “Idea Man” hinted that he might share some innovations of his own on the policy front.

“Especially in the areas related to, perhaps, some space things, there might be something in the cards in the future,” Allen said. “There’s nothing I’m going to talk about today, but clearly, I think everybody who’s on the frontiers of science sees the challenges the planet’s going to encounter. … All of us who care about the world going forward would like to engage the government more.”