Although the film has received acclaim for its realism of its premises and its general adherence to physical principles, director Alfonso Cuarón has admitted that the film is not always scientifically accurate and that some liberties were needed to sustain the story.
The film's cascade of debris is a very real possibility. This scenario is known as the Kessler syndrome, named after N.A.S.A. scientist Donald J. Kessler who first proposed the theory in 1978. A cascading Kessler syndrome involving an object the size of the International Space Station would trigger a catastrophic chain-reaction of debris. The orbiting debris field would make it impossible to launch space exploration missions or satellites for many decades.
When the sequence of Stone entering the I.S.S. (International Space Station) airlock and shedding her spacesuit was filmed, actress Sandra Bullock sat on a rig with a bicycle seat and had her right leg strapped into a two-part brace inside a specially made chamber. She then mimed movements that were carefully choreographed and a camera rig was rotated slowly to create the illusion of her's and the I.S.S.'s rotation. Lights were also placed in strategic spots to capture the shining of Sol in the window. In postproduction, Bullock's right leg and the braces were erased completely and recreated with C.G.I.
Because of Alfonso Cuarón's lengthy takes, Sandra Bullock had to memorize long combinations of precise movements to hit her marks at different points in the shot. She often had to coordinate her own moves with those of the wire rig attached to her and the camera.
In the opening scene, as Kowalski flies very close to the camera, astronauts holding a movie camera and boom mic appear to be reflected in his helmet visor. This is an in-joke by director Cuarón. The production crew's "reflections" were added with CGI to make it look like the scene was actually filmed in space, and that the post-production team failed to digitally paint-out those reflections.
Various mechanical sounds made by the spacecraft are heard on the sound-track as a result of conduction through the astronauts' bodies while they are in contact with the station. For example, when Ryan Stone is frantically trying to grab the handles as she flies by the station, the sounds of the station are heard while she is holding a handle, and they cease when she lets go. On the actual Lunar missions, the sounds of astronauts hitting their hammers on core sample tubes were conducted through their bodies and transmitted through their microphones.
Aningaaq, the man Dr. Stone talks to on the shortwave radio, is the main character of the short film Aningaaq (2013) directed by Jonás Cuarón. In that movie he is an Inuit fisherman with a dog sled and a baby daughter, camping on the ice over a frozen fjord. Aningaaq is trying to tell Stone that one of his dogs is very ill, and he is considering putting it out of its misery. The inspiration for the short film came to Cuarón and his son when they were doing location scouting for a different movie in Greenland. In a deserted area where normally only seals live, they encountered a lone Inuit fisherman who was very hospitable, and invited them over. They wondered what a man who lives all by himself in such a remote area would do if he had no one else to talk to, and so the idea for the short movie was conceived.
The actual Chinese Space station is named Tiangong, "Heavenly Palace." At the time of the film's premiere, it consisted of one small, habitable module. The Tiangong program's goal is construction of a space station much like the one in the film by 2022.
Alfonso Cuarón, cinematographer Emmanuel Lubezki, and visual effects supervisor Tim Webber decided they couldn't make the film they wanted using traditional methods. For the space-walk scenes, says Webber, "We decided to shoot (the actors') faces and create everything else digitally." To do that, Lubezki decided he needed to light the actors' faces to match the all-digital environment. Whether the characters were floating gently, changing direction or tumbling in vacuum, the facial light would need to perfectly match Earth, Sol and the other stars in the background. "That can break easily," explains Lubezki, "if the light is not moving at the speed that it has to move, if the position of the light is not right, if the contrast or density on the faces is wrong." Lubezki suggested folding an L.E.D. screen into a box, putting the actor inside, and using the light from the screen to light the actor. That way, rather than moving either Sandra Bullock or George Clooney in the middle of static lights, the projected image could move while they stayed still. The "light box", key to the space-walk scenes was a nine-foot cube just big enough for one actor.
The film is ninety minutes long. In reality, the International Space Station travels at approximately 17,500 miles per hour, and orbits Earth every ninety minutes. The debris field also circles Earth every ninety minutes.
To prepare for shooting, Sandra Bullock spent six months in physical training while reviewing the script with Alfonso Cuarón. Cuarón said, "More than anything else, we were just talking about the thematic element of the film, the possibility of rebirth after adversity." They worked out how she would perform each scene, and her notes were included the previsual animation and programming for the robots. Cuarón and Bullock zeroed in on Stone's breath, "and how that breath was going to dictate her emotions," he said. "That breath that is connected with stress in some instances, but also the breath that is dictated by lack of oxygen." Their conversations covered every detail of the script and Bullock's character. "She was involved so closely in every single decision throughout the whole thing," Cuarón said. "And it was a good thing, because once we started prepping for the shoot, it was almost more like a dance routine, where it was one-two-three left, left, four-five-six then on the right. She was amazing about the blocking and the rehearsal of that. So when we were shooting, everything was just about truthfulness and emotion." James Cameron, best friend of Cuarón and a huge fan of the film, said "She's the one that had to take on this unbelievable challenge to perform it. (It was) probably no less demanding than a Cirque du Soleil performer, from what I can see. There's an art to that, to creating moments that seem spontaneous but are very highly rehearsed and choreographed. Not too many people can do it. ... I think it's really important for people in Hollywood to understand what was accomplished here."
Alfonso Cuarón and Jonás Cuarón developed the script at Universal Pictures. Universal hoped to attach Angelina Jolie to the project, but decided the film was too expensive, and put the film into turn-around. The film spent four years in development hell because the cinematography, visual effects, and realistic "story atmosphere" of vacuum were too challenging. Alfonso Cuarón had to wait for technology to catch up to his vision. That finally happened in 2009, with James Cameron's Avatar (2009).
According to British sound designer Glenn Freemantle, creating sounds for a film set in a soundless environment presented a whole new array of technical challenges. Freemantle used an acoustic guitar rigged with microphones on the outside and hydrophones on the inside. With the guitar immersed in a tub of water, Freemantle created sounds by rubbing and touching various items against the body of the submerged instrument to generate the ethereal sounds heard on the film's soundtrack.
Because there is no up or down in space, the opening 12 minute scene was originally rotated 180 degrees but an off-the-cuff decision to play it back upside-down was made and Alfonso Cuarón liked it so much, he decided to keep it upside-down in the official cut.
The actors could not be filmed using conventional means as they could not spend long amounts of time upside-down, which was needed for the range of movements. Because of this, elaborate mechanisms were created to rotate the camera, whilst the actors moved, to replicate this effect.
There are several references to Kowalski's hopes of breaking Anatoli Solovyev's EVA record. This is not for a single spacewalk (as of the end of 2014 that is jointly held by Susan Helms and James Voss, at 8 hours 56 minutes) but to the cumulative duration over a career. Between 17 July 1990 and 14 January 1998 Solovyev carried out sixteen EVAs on four separate missions, with a total time of 79 hours 51 minutes.
Actor Phaldut Sharma, who voiced as a goofy Indian astronaut, 'Shariff', chose the song "Mera Joota Hai Japani" for humming himself when the director asked him to play something light. The director thought the character would put the audience at ease and get a few laughs before the actual story kicked off. The lyrics of the song literally mean, "My shoes are Japanese, my pants are English, the red hat on my head is Russian, and yet my heart is Indian" - figuratively saying that an Indian, wherever he goes, whatever he eats or wears, at the very heart he'll always be an Indian. It is a classic Hindi song from Shree 420 (1955).
The space-suit that Dr. Stone puts on in the Russian Soyuz capsule has the number 42 on the patch. This places the film between September 2014 and March 2015 as the Expedition number 42 will be underway on the International Space Station.
According to real-life astronaut Michael J. Massimino, the orbit of the spacecraft would, in reality, be moving in the opposite direction through space. Ryan (Sandra Bullock')'s 'trained' astronaut would not be gasping desperately for oxygen in space given the limitations of its supply. Her 'underwear' would most likely consist of a total body stocking instead of the shorts and skimpy top worn onscreen.
Since the Hubble Space Telescope operates at high earth orbit and was just within the space shuttle's range, and the International Space Station operates at low earth orbit, it was well beyond the reach of the film's survivors. In 2009, when the Hubble was last maintained, a 2nd shuttle had to be prepared, just in case a rescue was needed. In an emergency, there was no way the maintenance crew could intercept the ISS. As it was, the mission was a complete success and the crew returned safely home without incident.
Before filming began, the entire film was made and rendered, frame-by-frame, without lighting using basic digital models; when Alfonso Cuarón approached the producers and they suggested changes, Cuarón told them "no; this is exactly what the film will look like."
For most of Sandra Bullock's shots, she was placed inside a giant, mechanical rig. Getting into the rig took a significant amount of time, so she chose to stay in it for up to 10 hours a day, communicating with others through a headset. Alfonso Cuarón said his biggest challenge was to make the set feel as inviting and non-claustrophobic as possible. The team attempted to do this by having a celebration each day when Bullock arrived. They nicknamed the rig "Sandy's cage" and gave it a lighted sign.
Kowalski mentions landing at Edwards, a reference to Edwards Air Force Base in California. It was the primary landing site for all shuttle missions until 1991, then a reserve landing site until the Space Shuttle program ended in 2011.
Shooting long scenes in a zero-g environment was a challenge. Eventually, the team decided to use computer-generated imagery for the spacewalk scenes and automotive robots to move Sandra Bullock for interior space station scenes. This meant that shots and blocking had to be planned well in advance for the robots to be programmed.
Dr. Stone states that she is in a Soyuz T.M.A.-14M. The Soyuz T.M.A.-14m is the spacecraft that launched the crew for Expedition 41. The Soyuz T.M.A.-14M will most likely remain on board the space station for the Expedition 42 increment to serve as an emergency escape vehicle.
When Matt and Ryan are making their way to the International Space Station, he finds out Ryan is from Lake Zurich, Illinois, and states that it's 8:00 P.M. there. They are floating over Egypt where it is 3:00 A.M. locally.
Gravity (2013) was more expensive the real Indian Mars Orbiter Mission also known as Mangalyaan. The budget of Gravity (2013) was $100,000,000 USD (estimated) against the $74,000,000 USD budget for the mission.
The trivia items below may give away important plot points.
A long-time rumor claims that N.A.S.A. provides suicide pills to astronauts for worst-case scenarios. N.A.S.A. has denied this for decades. Some people have said that it would be easier and more comfortable to reduce oxygen in the chamber, as depicted in the film.
Ryan's hallucination of seeing Kowalski again in the space pod was George Clooney's idea. According to Clooney, Alfonso Cuarón was unable to come up with a satisfactory resolution for the character despite many revisions of the scene, including removing the dialogue, until Clooney offered to take a shot at rewriting the scene himself.
The entire film was shot on digital cameras. However, Emmanuel Lubezki stated that the closing sequence, after Ryan lands back on Earth was shot in sixty-five millimetre in order to give a hyper-reality look.
In the International Space Station, when Dr. Stone finds out there is a fire, besides the notebook monitor displaying the warning shows two photos of the screenwriter Jonás Cuarón and his family, and also a photo with reference to a short film Le voyage à travers l'impossible (1904) directed by Georges Méliès
After removing her suit in the Soyuz air lock Dr. Stone rests in a natural position, which in a zero gravity environment is the fetal position. The umbilical cord-like tubes surrounding her add to the symbolism of a helpless infant in the security of the womb. After the trauma of the beginning of the movie, Dr.Stone concedes that she is the sole survivor as she looks out over the eye of a hurricane. This is symbolic of her own situation - a moment of peace before the fire alarms go off and she is plunged back into desperate chaos.
When Sandra Bullock attempts to make contact with NASA at ISS, at the left-hand side of the radio, there is a copy of the Vitruvian Man which is a famous drawing by Leonardo da Vinci. Encyclopaedia Britannica online states about it: "He believed the workings of the human body to be an analogy for the workings of the universe." This work serves as the base of the patch on the right shoulder of the space suit of a spacewalker.
When Dr. Stone enters the Soyuz and puts on the Russian space suit, the Russian name on the suit reads in English "L. Demidov", with the Russian translation above it. L. Demidov is possibly abbreviated for the name Leo Demidov, who was a Soviet MGB agent that investigated into a series of child murders in the 1950s, originating from the novel "Child 44" by Tom Rob Smith. It is likely to associate with Dr. Stones admittance to losing her daughter at the age of 4.