A plane so big it has two cockpits and looks incapable of taking off flew yesterday for the first time.

Developed by Stratolaunch Systems, the aircraft is essentially a flying launchpad. The idea is that it will fly to 35,000 ft and then launch a satellite-bearing rocket into low-Earth orbit. Among the plane’s advantages, it can take off from a regular runway and fly above or around bad weather.

But as Quartz’s Tim Fernholz pointed out last August, there are now many competing companies offering relatively cheap launch services. That has led some to speculate that the plane, designed by aerospace icon Burt Rutan, might really be a secret project for the US military—perhaps even for anti-satellite weapons.

However the improbable plane is ultimately used, it is a sight to behold in action. The late Microsoft co-founder Paul Allen, who founded Stratolaunch Systems in 2011 before he passed away last October, would no doubt be proud.