The Gravity You Didn't See, Starring Natalie Portman, Robert Downey Jr. And Many More

Alfonso Cuaron's Gravity opens in sneak previews tonight and everywhere tomorrow, and as you might have heard, we're pretty crazy about it. Cuaron's technical wizardry, which creates the actual feeling that you are somehow floating in space, is the big sell, but the performances from Sandra Bullock and George Clooney elevate the film to some surprisingly emotional highs. Sure, they were cast partly because they're big names who can draw audiences, but they add a key human component to what could have just been a special effects extravaganza.

But, until not all that long before production began, neither of them was going to be involved in the film at all. If you're a fan of Cuaron from films like Harry Potter and the Prisoner of Azkaban or Children of Men you may have been following the long development of Gravity, and the many actors who attached their names to it, but if all you know is the posters featuring Sandra Bullock in a space helmet, time to catch up!

Angelina Jolie

In the beginning, way back in 2010, Angelina Jolie was Cuaron's top pick to take the lead role of Dr. Ryan Stone. In our breathless reporting we said she had "bailed on Wanted 2" to make it happen, which is hilarious because Wanted 2 is seriously never going to happen no matter what they say and Jolie had no business being in it anyway. At the time I also said Gravity "sounds a lot like Duncan Jones's Moon," and that "No, I seriously doubt this movie will manage to be better, despite my abundant love for Cuaron." Moon is still great, but hindsight proves me a major dolt on that one. Oh, and then Jolie bailed on the project after all.

Robert Downey Jr.

Only weeks after Jolie got on board and almost immediately departed, Robert Downey Jr. agreed to join the cast as Matt Kowalski, a character is essentially written as a non-superpowered version of Iron Man-- capable of many wisecracks while inside a bulky suit. Earlier this summer, while being completely gracious, Cuaron explained why Downey Jr. probably wouldn't have been such a great fit for the film anyway: "It was very clear that the technology we were going to use -- it was not the most compatible thing for what Robert is the best at. That is, he takes one scene and he just starts riffing. And because of the technology that we use, it's pretty much limited. We have to preprogram the film before shooting.” That's a nice way of saying "he doesn't like to use the script, and this film lives and dies by the script." And Downey Jr. has the Avengers to let him ad lib, so it all seems to have worked out.

Scarlett Johansson

While Downey Jr. was still attached, Scarlett Johansson's name popped up as a potential option for the female lead. This was still back in 2010, only a few months after Johansson's first appearance as Black Widow in Iron Man 2, so she had recently proven action chops that suggested she could fit the part. But at 26 years old that summer, she was also a liiiiiiittle young to play a grieving mother and top-flight scientist. Not to be ageist, but come on.

Blake Lively

I know, right? It seems impossible now, but at one point in that crazy of summer 2010 we were trumping up "the battle of the blondes," as Johansson and Lively were the rumored top choices for the female lead role. Lively had just finished shooting but had yet to release Green Lantern, which could have made her a big name if it hadn't flopped so terribly. Of all the alternate casting choices for this film, this one's the most mind-boggling by far.

Marion Cotillard/Carey Mulligan/Olivia Wilde/Naomi Watts/Abbie Cornish/And Many More!

At some point Warner Bros. got so panicked about finding the right female lead for the film that they auditioned just about everybody, and even went back and begged Angelina Jolie to take it, which she again turned down. The pressure was on to cast a woman who could open a movie on her name alone, and at the time Jolie was pretty much the only game in town. It was September of 2010, just a few months after Sandra Bullock's surprise Best Actress Oscar win and a few months before the surprise box office success of Black Swan. Which leads us to…

Natalie Portman

Portman was part of that crazy auditioning derby, and at one point rumor had it that Portman had the role sewn up if she wanted it. By then Black Swan was playing festivals and earning raves, especially for Portman in the role that would eventually earn her own Best Actress Oscar. Portman had the same age problem that Johansson did, but suddenly even more bankability, and seemed like a pretty reasonable alternative to Jolie. Except it required Portman to actually want the part, and the accompanying physical challenges…which apparently she wasn't quite up for.

Sandra Bullock

It has to be weird that Bullock's approach to the film she's now promoting was in the context of being a runner-up, available for the role if Natalie Portman passed. When Portman moved on she did exactly that, with a reportedly higher salary than Portman would have commanded but a big hit (The Blind Side) recently behind her, and another one (The Heat) on the horizon, though of course nobody knew it at the time. Sometimes a crazy casting process can look like fate in retrospect.

George Clooney

After all that craziness finding the female lead, Robert Downey Jr. then left the production in the lurch, off to fulfill his commitments not only to The Avengers but the zillion other projects he'd managed to attach himself to. By some miracle, George Clooney was actually available, and took on the much smaller male lead, requiring a few weeks of work as opposed to the months Bullock spent on set. And that's how two of the biggest A-list stars working today wound up fronting this expensive sci-fi movie-- after lots of other options turned it down.

Katey Rich

Staff Writer at CinemaBlend