Billionaire Paul Allen’s spaceship project has reached a milestone in the form of the world's widest garage door.
The door will make way for a strange vehicle under assembly in the Mojave Desert.
Allen's team has the most unusual plan, out of several private space ventures, for sending people and satellites into orbit. They'll launch their rockets from the belly of a gigantic airplane, which looks like two Boeing 747s bonded together. And constructing that bizarre jet requires a building wide enough to shelter it.