Summary
Surviving in space without a spacesuit for approximately 30 seconds would lead to irreversible harm and ultimately death, owing to the absence of oxygen, as stated by former NASA astronaut Chris Hadfield.
After approximately 15 seconds, an individual exposed to the vacuum of space would experience unconsciousness as a result of insufficient oxygen supply to the brain through the bloodstream. Although the depiction of Star-Lord's facial swelling in Guardians of the Galaxy Vol. 3 may be exaggerated, it contributes to the authenticity and emotional intensity of the scene, ultimately enhancing the scientific accuracy of the movie compared to its predecessor, the first Guardians of the Galaxy film.
The actual science behind the scene in Guardians of the Galaxy Vol. 3 where Star-Lord is almost dying in space is revealed by a real-life NASA astronaut. In the climactic scenes of James Gunn's Marvel Cinematic Universe trilogy finale, Star-Lord propels himself from the High Evolutionary's ship to Knowhere but becomes stranded in space. Ultimately, he is saved by a redeemed Adam Warlock. However, before his rescue, an emotional moment takes place where the other characters watch as Star-Lord slowly succumbs to death. Despite the emotional impact, this depiction is not entirely scientifically accurate.
During an interview with Vanity Fair, retired NASA astronaut and engineer Chris Hadfield dissects the accuracy of various movies, including Guardians of the Galaxy Vol. 3. While Star-Lord's fate in the MCU seems grim as he faces death in space, Hadfield explains that it is possible for someone to survive in space for approximately 30 seconds.
Hadfield discusses the consequences of being stranded in space without a space suit. He explains that a person would remain conscious for approximately 15 seconds, and after 90 seconds, their body would sustain irreversible damage leading to death. Please find his complete remarks below.
According to our estimation, it is possible to survive outside a spacecraft without a space suit for around 30 seconds without significant issues. However, once the time surpasses approximately 90 seconds, critical and irreversible damage will occur, ultimately resulting in fatality. In essence, after 90 seconds, one would effectively become a satellite.
Within approximately 15 seconds, all the oxygen present in your bloodstream will have completed the journey through your lungs in the opposite direction, subsequently being exhaled. Consequently, after this duration, your blood will lack sufficient oxygen, leading to unconsciousness when it reaches your brain.
Observe the evident facial swelling—he is experiencing genuine physiological changes. In the context of venturing into space without a helmet, while your lungs may collapse to some extent, your blood would also undergo an unsettling reaction similar to the effervescence of opening a can of carbonated cola. Releasing the internal pressure would cause bubbles to form within your blood, as well as within your facial tissues and throughout your entire body. This would result in considerable swelling, albeit not to the extent currently observed in the depicted scenario.
Suddenly, frost appears on his face—a highly improbable occurrence. There is no moisture on his face, therefore, instantaneous freezing is impossible. The concept of thermal mass is important here, as it compares to placing a large roast in a freezer. The freezing process does not occur instantly; rather, it takes a considerable amount of time. The majority of the effects are happening internally, which is difficult to portray to the audience. Hence, the exaggeration of the facial transformation.
Personally, I believe it would have been more fitting if this scenario had involved Groot instead. In that case, Groot could have effortlessly emerged from one ship, uttered his iconic line, "Groot!", and swiftly boarded the other ship without any major complications.
How GOTG 3's Star-Lord Scene Is More Accurate Than Guardians of the Galaxy
Guardians of the Galaxy Vol. 3 is not the first time Gunn has included a scene where a character slowly dies in space. The first Guardians of the Galaxy movie also had a similar scene. In that movie, Nebula destroys the pod Gamora was flying in near Knowhere, leaving her floating in space. However, Star-Lord saves her by giving her his mask and calling Yondu and the Ravagers for help. Both Gamora and Star-Lord survive, but they experience a few perilous moments in space where their skin freezes over. This is consistent with how Star-Lord's near-death in Vol. 3 is depicted, but there is one difference.
In Guardians of the Galaxy, Gamora and Star-Lord do not appear to swell up to the same degree as Star-Lord does in Vol. 3. It is unclear why the depiction of what happens to a person left unprotected in space has changed from the first movie to the third, but according to Hadfield's explanation, it makes the third movie more scientifically accurate. However, it is not entirely accurate, as Hadfield mentioned, but including the detail of Star-Lord's face swelling adds a touch of realism and intensifies the emotional impact of the scene in Guardians of the Galaxy Vol. 3.
Source: Vanity Fair
