With a technical setup that wound up mirroring the communications between a stranded astronaut and Mission Control, Cuarón corresponded with Bullock through hidden headphones in her suit during filming. “Poor Sandra, she was alone there in that box,” Cuarón told Rolling Stone back in 2013. “I was literally 15 minutes away, with banks of computers and stuff, communicating with her through radio, like I was Houston and she was an astronaut.”
As the minimal cast and crew started to get into the flow of production, it became too cumbersome and time-consuming for Bullock to repeatedly enter and exit the Light Box. In a practical but still brave decision, Bullock chose to stay strapped inside the state-of-the-art rig for incredibly long periods of time. To open the cube and close it again would take up to 25 minutes. Add on all of the endless adjustments, calibrations, and general troubleshooting, and Bullock’s resolve allowed for the tension to keep ramping up instead of dissipating every time the cube had to reset.
To help brighten her mood during the long days, Cuarón would beam calming, atmospheric music into Bullock’s headphones and occasionally surprise her by lighting up the massive array of LED screens with images of her kid. For all the sacrifice and cramped conditions that Bullock endured, the Light Box was still relatively safe and she was never in any real danger. After battling long hours and claustrophobia, there was one day in particular, however, that stood out to Bullock where she was legitimately concerned for her safety.