Chris Hadfield is a retired NASA astronaut and engineer. Meaning he knows a thing or two about what it takes to go into space in real life. Hadfield uses his expertise to tell audiences which Hollywood space-based films had the most believable setup. Surprisingly, he had some particularly harsh words for 2013 best picture Oscar nominee Gravity.

"[Gravity is] so far from reality that I want to turn my head."

Words that are sure to surprise many fans of the film. After all, unlike the more over-the-top space films like Star Wars or Guardians of the Galaxy, Gravity is considered a gritty and realistic take on what it takes to be an astronaut. The movie tells the story of a group of astronauts who are stuck in space after the mid-orbit destruction of their satellite.

The rest of the team is picked off one by one, leaving lone astronaut Dr. Ryan Stone, played by Sandra Bullock, to try to make her way back to Earth. For Hadfield, his issues with the film begin with the manner in which the movement of the satellite is depicted.

"The satellite goes whizzing by at about maybe 120 miles per hour. The real satellites are going 5 miles a second, 17-and-a-half thousand miles an hour. How that satellite in the film is going by where you can identify what it is [makes no sense]."

Okay, you could argue that the speed of the satellite was slowed down to let the audience know what it was before it zoomed out of their view. It's just a more cinematic choice. Hadfield's next problem was with the scene in which Sandra Bullock's character takes off her strap to escape from the satellite debris.

"When she releases her little strap, she flies away in a whole new direction as if there was some force on Sandra that wasn't on the arm. How come she has a different gravity than the arm does?"

Even George Clooney, who played the charming supporting character of Lieutenant Matt Kowalski, who sacrifices his life to give Bullock's character a chance at making it, did not escape criticism.

"Everyone on the crew, the dialogue, they're all yelling back to Houston as if Houston is going to help them right here. George Clooney is asking permission to go help Sandra Bullock. It's not astronaut behavior. It's not logical behavior. It's so execrable from actual, practical realities of space flight."

Okay, but what about the triumph of having a woman lead this kind of high-concept venture? Surely it's a wonderful thing that an actress was front and center of a movie set in space for once, instead of pulling a Princess Leia and waiting to be rescued from danger by a man? But nope, Hadfield believes the character of Ryan Stone is far from an inspiration for women who want to become astronauts.

"The most experienced astronaut in American history is a woman, it's Peggy Whitson. In this movie, Sandra Bullock has only been an astronaut for less than a year. When she's faced with a problem, she's panicking and has no idea what to do. George Clooney is driving around like some sort of space cowboy and he's the only one who has any idea what's going on. I think it set back a little girl's vision of what a woman astronaut can be an entire generation."

"Sandra Bullock did a great job of portraying the character in the movie but the character that they wrote for her was disappointing. That's what I would've changed. Get it to represent what astronauts are really like and then build the story around that. Don't just make it the perils of [this woman] and she needs George Clooney to magically save the day and tell her what book to open to do the right thing."

These comments come from a Varity Fair. You can watch the interview below.