When the Atlanta Falcons' new $1.5 billion home opens with an exhibition game Saturday night, the most expensive and most discussed feature of Mercedes-Benz Stadium will remain closed.

The retractable roof isn’t ready to retract, forcing games to be played with it in the closed position until mechanization is completed. Falcons and stadium officials don’t know exactly when they’ll be able to open the roof for a game, but they say it’ll be sometime this fall.

"I don't get upset, to be honest with you, over two or three months delay," Falcons owner Arthur Blank said. "The roof works. It just doesn't open and close in 12 minutes yet, but it does open and close.

Read more on the retractable roof on myajc.com. The $1.5 billion stadium will officially open -- with a closed roof -- Saturday night as the Falcons host the Arizona Cardinals in an exhibition game.

Here are some things you need to know and news you can use as the countdown to the big day continues:

What to know about first few games inside Mercedes-Benz Stadium

> How getting to Mercedes-Benz stadium differs from the Georgia Dome

> Everything you need to know about food and drink at Mercedes-Benz Stadium

Antonia Thomas serves food at The West Nest concession stand during a tour of Mercedes-Benz Stadium on Tuesday, August 15, 2017. The West Nest is part of Westside Works, a program started by the Arthur Blank Family Foundation as part of an attempt to turn around Vine City and English Avenue, two neighborhoods near the new stadium.

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