Brace yourselves Nerf Herders ... TMZ obtained a photo of what looks like the beginning stages of Han Solo's famous spaceship the Millennium Falcon!!!

Sources close to the Rebel Alliance tell us the pics were taken inside an uber-secret location in the UK -- where different set pieces, props and creatures are being constructed.

At first glance, it looked like run-of-the-mill set pieces ... until one of our top "Star Wars" nerds in the office spotted the legendary Millennium Falcon in mid-construction -- at least that's how it looks.

It also looks like they're building an X-wing.