Room 26 is a humble little space behind a plain white door, in the upper reaches of Arthur Ashe Stadium. It may not be the nerve center of the 2016 US Open, but it’s close. In fact, over the next fortnight, it might be the most scrutinized location outside the playing courts on the 42 acres of the USTA Billie Jean King National Tennis Center.

Not much bigger than a walk-in closet, cluttered with computers and cables and a wall-sized, thermal-imaging computer rendering of the roof that shows hundreds of real-time temperature readings, it is the no-frills, high-tech command center for what is perhaps the most eagerly awaited (and expensive) lid in the annals of American sport.

It is the place where two taps on a computer touch screen –“Full Close” and “Start Sequence” are the go-to tabs – will, in 5 minutes, 42 seconds, render Ashe an indoor stadium, bringing closure to more than a dozen years of studies, designs and virtually every construction challenge on earth, from wicked winter weather to figuring out how to support an 11-million-pound structure that is built on ash landfill. The solution – a roof that is actually a freestanding umbrella hovering15 inches over Ashe Stadium proper, supported by eight steel piles pounded 175 feet deep into the Queens earth – will ensure that America’s Grand Slam will never again spill into a third week.

“It’s been a massive undertaking,” said Danny Zausner, Chief Operating Officer of the entire NTC facility, and the USTA’s point man on the project.

If you’d prefer to call Room 26 the Retractable Roof Room, nobody would argue, least of all Mark Sharamitaro, the mechanical maestro who designed the moving pieces of the two, one-million pound panels, a burly, bearded grandfather from Ohio who has never attended a professional tennis match in his life, until now.

You ask Sharamitaro, 49, the president of Morgan Automation in Alliance, Ohio, the man who, along with two Morgan associates, will be touching the screen in Room 26, if he feels like an expectant father. He smiles.

“That’s exactly it,” he said. “It’s my baby. I expect to feel excitement, but in the roller coaster of it all, it will be nerves, fear, (everything).”

USTA officials are quick to remind fans that the Open remains fully an outdoor event. The roof will not close because of high heat or high winds. It will close only if there is rain, or the threat of rain.

“The goal here is to play as long as you can without closing the roof,” said Ed Bosco, a climate-control expert and managing principal of M-E Engineers, and another denizen of Room 26. “This is an open event, and we want it to be open as much as possible.”

The decision of when the roof will close resides solely with Brian Earley, the tournament referee, who will ultimately decide if he wants the closing process to begin. Well before that, though, top USTA officials will be consulting with the meteorologists on site, and with Bosco, who will be closely monitoring atmospheric conditions and taking steps to precondition the stadium in anticipation of a possible closing, by closing the 54 shutters that surround the upper bowl of the stadium and/or activating air management systems that will prevent condensation from forming.

While the roof can close within minutes, the preconditioning of the stadium might take as much as two hours. Bosco will monitor the 65 sensors that are located around the bowl that measure temperature and humidity and dictate whether any further steps need to be taken to ensure optimal conditions.  “There’s quite a lot that goes into the whole thing,” said Chuck Jettmar, Managing Director of Capital Projects and Engineering for the USTA.

Generally, once the roof is closed for a match it will remain closed, though it can be re-opened at Earley’s discretion. The roof will be closed at the end of play each night regardless of weather, and reopen in the morning, assuming the forecast cooperates.

Weather data collected over the last 11 years shows there is an average of 19.35 hours of rain during the two weeks of the US Open. That the inclement weather has often hit at the worst possible time (rain delays pushed the men’s final into the following work week for five consecutive years between 2008-12) ultimately persuaded the USTA to join the Grand Slam covered-court club, along with Wimbledon and the Australian Open. The process wasn’t easy, or cheap –$150 million isn’t quite loose change – but USTA officials are certain that the Open’s new, 150,000 square-foot roof will be a great thing for all constituencies – players, fans and network partners.

In Room 26, near the top of the world’s biggest tennis stadium, the roof team stands ready—ready to see to it that players can play, and keep playing, no matter what the forecast brings.