Ad Astra director James Gray has said he wanted the movie about an astronaut searching the galaxy for his missing father to be "the most realistic depiction of space travel that's been put in a movie."
Ad Astra, already available on digital, is out on Blu-ray, 4K, and DVD on Tuesday, and in an exclusive clip from an Ad Astra featurette called "Reach for the Stars," Gray talks about working with NASA to make the science believable.
"The exchange of ideas, and where they think things are going -- you want to get the details right," he said. "I've called them up in 2 in the morning and asked, 'Would this actually happen?'"
NASA technical consultant Robert Yowell, a former NASA engineer, also had a few things to say about the science sharing the screen with Brad Pitt.
"What Gray was looking for in terms of realism was the physics," Yowell said in the video. "For instance, 'Could you fire a gun on the moon?' The answer is yes. A bullet has its own oxidizer that comes right out of the barrel."
Another question Yowell tackled for the movie was what blood looks like in space: "Any fluid in spaces in zero gravity will tend to become a sphere."
Discuss: Get a closer look at Ad Astra's science in this exclusive clip from the Blu-ray version
Be respectful, keep it civil and stay on topic. We delete comments that violate our policy, which we encourage you to read. Discussion threads can be closed at any time at our discretion.