The Space Stone is one of the six Infinity Stones, the remnant of a singularity that predates the universe, which represents the element of space. Housed within the Tesseract, over the course of history it was wielded by many individuals, including Johann Schmidt of HYDRA, Mar-Vell of the Kree Empire, the Skrulls, and Loki of Asgard. During the Infinity War, the Tesseract was shattered by the Mad Titan Thanos, who put the Space Stone inside his Infinity Gauntlet.
World War II
After helping to found S.H.I.E.L.D., Howard Stark studied the Tesseract for some time and eventually theorized a new element based on its atomic structure. Due to the technology of his time, he was unable to actually synthesize the new element and instead substituted it with Palladium in his Arc Reactor prototypes. Howard left detailed notes on both the Tesseract and his new element in the hopes that his son would one day succeed where he had failed. Following Howard's passing, the Tesseract remained in S.H.I.E.L.D.'s care.
The Tesseract eventually found its way into the possession of Project P.E.G.A.S.U.S.. One of the members, Doctor Wendy Lawson, was in fact a Kree scientist named Mar-Vell who was inspired to use the Tesseract's power to create a Light-Speed Engine to try and help the Skrulls under her protection. Her research eventually drew the attention of Yon-Rogg who sought to claim the Tesseract for the Kree Empire only for the Light-Speed Engine to be destroyed when he came to confront the rogue scientist, its Space Stone derived energies bathing and bonding to Carol Danvers. In truth, the Tesseract had been safely stored in Mar-Vell's orbital laboratory. Six years later, Yon-Rogg's Starforce returned to Earth to try and claim the cube but Danvers and her allies managed to keep it from the Kree, concealing it within the Flerken Goose who later regurgitated it.
Following his defeat by Thor and banishment from Asgard, Loki found himself in the territory of Thanos who agreed to supply Loki a Chitauri army with which to conquer Earth in exchange for the Tesseract. Via remote manipulation of its energies, Loki used the Space Stone within the Tesseract to travel to Earth and brainwashed several S.H.I.E.L.D. agents and personnel, including Selvig, to safely contain the Tesseract's energies to open a stable wormhole for the Chitauri to invade through. Though the Chitauri made planetfall, they were defeated by the newly-formed Avengers. Following the battle, Thor used the power of the Space Stone within the Tesseract to take it, along with himself and Loki, back to Asgard.
Four years later, as the recently freed Hela inspected the treasures in the vault, she admitted the Tesseract was "not bad", but dismissed it in favor of the Eternal Flame. When Loki sought to enact Ragnarök, he passed by the Tesseract and secretly took it with him as Asgard was destroyed. Unaware of this, Thor assumed the Tesseract had been destroyed with the rest of the planet. Detecting the Tesseract aboard the Statesman, Thanos had the Sanctuary II intercept the refugee ship.
In Thanos' Possession
After slaughtering half of the remaining Asgardians, Thanos tortured Thor with the Power Stone to force Loki into surrendering the Tesseract. Though Loki attempted to use the Tesseract as a distraction long enough for Hulk to defeat Thanos, the Titan managed to best the gamma-beast and claimed the Space Stone, shattering the Tesseract in the process. After placing it in the Infinity Gauntlet, Thanos used its power to halt one of Loki's daggers before teleporting himself and the Black Order off the Statesman after using the Power Stone to destroy it.
Though continuing to use the Sanctuary II as a home base, Thanos had no need of his warship's traveling capabilities as he could simply use the Space Stone to open portals to anywhere he desired to go. He first used this to travel to Knowhere for the Reality Stone where he abducted Gamora. Bringing her back to the Sanctuary II, he revealed to her that he had captured Nebula and tortured her using the Power and Space Stones to force the Zehoberei into revealing the Soul Stone's location, and used the Space Stone to travel to Vormir, taking her with him to collect it.
Thanos then made his way to his homeworld where he was confronted by the Avengers and Guardians of the Galaxy. Thanos made liberal use of the Space Stone during the battle first using it to harmlessly funnel the kinetic energy of Iron Man's projectiles before sending it back at the hero. In an ultimate display of the Space Stone's power, he used it to send the Power Stone's energies to Titan's moon, ripping it to shreds before using the Space Stone to send the chunks hurtling towards the planet's surface.
Thanos later used it to collapse the remnants of a doorway to the Mirror Dimension into a singularity which he then used as a weapon against Doctor Strange before using it with the Reality Stone to briefly alter Titan's terrain to defeat the sorcerer. Upon Thanos defeating Iron Man, he prepared to use all four of the Stones in his possession to execute him before Strange bartered the Time Stone for his ally's life. Thanos used the Space Stone to teleport himself directly to the Mind Stone's location in Wakanda.
Upon arrival, he used the Space Stone to phase the Hulkbuster armor through him and into a rock wall as well as knock down Falcon before using it to vaporize all of War Machine's bullets and then create compression forces around the War Machine armor, grounding it. As he neared the Mind Stone, he used the Space Stone to defend himself from Scarlet Witch's stream of energy. After completing the Gauntlet and being stabbed by Stormbreaker, Thanos utilized all six Stones to wipe out half of all life in the universe before using the Space Stone one last time to teleport himself to an alien farmland.
3 weeks after the Decimation, Thanos destroyed all the Infinity Stones, including the Space Stone, by using the powers of the stones themselves, in order to eliminate any possibility of reversing the Decimation.
5 years later, the remaining Avengers came up with a plan to reverse the Decimation: travel back to specific points in time, get the Infinity Stones from there, and then using them to bring everyone who died back to life.
In order to retrieve the Space Stone, Tony Stark and Scott Lang (along with Bruce Banner and Steve Rogers) traveled back to 2012, moments after the Battle of New York, back when the Space Stone was inside the Tesseract. It was accompanied by a team of S.H.I.E.L.D. agents and the younger versions of Stark and Thor, who planned to take the Tesseract and Loki back to Asgard. However, on their way, they were stopped by Alexander Pierce, who demanded the Tesseract as it was S.H.I.E.L.D. property since World War II.
While the entire hall argued, the older Stark instructed Ant-Man to go inside his younger self's Arc Reactor and shut if off, causing him a cardiac arrest as a distraction. The plan worked, but as Stark was walking away, he was accidently knocked out by a younger Hulk. This caused the Tesseract to fall right into Loki's hands, who used the Space Stone inside to teleport away.
Stark and Rogers went further back in time to 1970 were they could find another past version of the Tesseract and more Pym Particles. The Space Stone within the 1970s Tesseract was extracted and added to the Iron Gauntlet so that the Decimation could be undone. After the Battle of Earth, the stolen Space Stone was returned to its proper timeline, apparently also placing it inside the Tesseract once again.
As the Infinity Stone that represents and governs over space, the Space Stone grants the wielder absolute control over space itself. It is primarily used to open portals to other locations and can even allow interdimensional travel. As one of the six Infinity Stones, the Space Stone ranks as among the most powerful artifacts in the universe, with Black Widow saying it has the power to wipe out an entire planet. Out of all the artifacts on Odin's Vault, it was the only one that managed to impress Hela, who said it was "not bad". Like with all other Infinity Stones, it can only be used safely by beings of sufficient power. Lesser beings are quickly consumed by it, to the point of being banished into the depths of space through a wormhole, as evidenced with the Red Skull being quickly consumed by it when he touched it and was then transported to Vormir. Steel is quickly melted through by touching it and specialized gloves will only keep the Stone from consuming any human bearer for seconds before killing them, with it still being painful.
Drawing power from space, the Space Stone's source of energy is so great that many consider its volumes of energy to be unlimited. Due to this, the Space Stone is capable of powering or repairing objects and artifacts of incredible power, such as the Rainbow Bridge. A single spark of its power was enough to create a small explosion. HYDRA was able to use the Space Stone's energy within the Tesseract to power advanced vehicles and weapons of mass destruction including guns, tanks, and bombs that vaporized their targets. The Space Stone also emits low levels of Gamma Radiation when inside the Tesseract, which interfered with Selvig's methods of harnessing its energy source, and later allowed the Avengers to track its movements.
Notably, the Stone is also implied to have a form of limited sentience and degree of intelligence. Remarks by Erik Selvig refer to the Tesseract as a "she", even before his domination by the Mind Stone. He frequently describes the Stone as exhibiting and performing sentient emotion and acts, such as "misbehaving", and wanting to "show [Earth] something." When they turn off power used to harness its energy, the Space Stone turns the power back on using its energy source. Wherever the Space Stone is drawing its cosmic power from, it appears to be able to be manipulated from the other endpoint as well. Curiously, when the Tesseract was brandished by an unworthy Red Skull, a man who greedily sought the Stones themselves, the Space Stone seemed to purposefully banish him to Vormir, where he would be doomed to an ironic fate -becoming the eternal keeper of the Soul Stone, but forever unable to wield it himself.
After Thanos inserts it into the Infinity Gauntlet, it is shown that when wielded by someone who truly understands and masters its powers, the Stone's control over space can be used to gain a wide range of potent and dangerous capabilities that are not limited to simple teleportation, with Thanos displaying that with his strong understanding and mastery over the Space Stone's powers, he is able to use the Stone liberally in battle to great effect, as seen by his skillfully warping the fabric of space to achieve a variety of powerful effects that he very effectively employed.
Aside from the ability to create portals and wormholes throughout the Universe, Thanos has been shown to be able to expertly use the Space Stone to warp the fabric of space to generate powerful spatial pressure around his surroundings, capable of crushing, pulling and freezing with tremendous force in a manner akin to telekinesis enable him to manipulate and move objects with just a single gesture of the Gauntlet, an ability that proved to be among Thanos's most often used. Thanos was able to use the Stone to casually freeze Loki's knife mid-stab in an instant, effortlessly crush the guns on War Machine Armor: Mark IV and ground it, and crush the wings on the EXO-7 Falcon to knock him down. The Space Stone's spatial induced telekinesis is so strong that Thanos was even able to use it to telekinetically pull the shattered fragments of Titan's moon across space to rain down on the attacking Avengers and Guardians of the Galaxy during the Battle of Titan.
He also gains far more varied capabilities in combat apart from telekinesis using the Space Stone, such as the ability to create powerful, and devastating singularities capable of compressing and sucking anything in their path, as after shattering a gateway to the Mirror Dimension thrown by Doctor Strange, Thanos used the Stone to compress the gateway's fragments into a destructive black hole to throw back at the sorcerer. Thanos even shows that he has the skill needed to use the Space Stone to phase and unphase objects out of space, rendering them incorporeal and just as easily make them corporeal again, such as when Thanos used the Stone to phase the attacking Hulkbuster out of space, causing the Avenger to fall through the Titan harmlessly and fall into a cliff and then make him corporeal again to trap him in solid stone. Thanos also shows he can manipulate the Space Stone's energy reserves to conjure extremely strong blue energy force-fields capable of instantly vaporizing the bullets of War Machine's armor and even blocking the energy of Scarlet Witch.
Thanos displays the ability to combine the Space Stone with the other Stones to enhance its effects and make it capable of a larger variety of feats. Combined with the Power Stone, Thanos can even warp and manipulate energy, using the Gauntlet to absorb the explosive energy of Iron Man's missiles, and redirect it at the Avenger as a single concentrated beam of fiery energy. Together with the Reality Stone, Thanos can manipulate the terrain at such a scale as of to pull the surface of Titan itself towards him in order to grab the mid-air Doctor Strange.
In addition, Thanos displays that with his incredible level of precision and control over the portals opened by the Space Stone, he is able to collectively select what gets teleported alongside him and can even remove objects forcibly attached on his person, as he removed the impaled Stormbreaker from his chest upon warping away. It is also shown that the portals's size can be decided by the wielder and can take multiple people or just one other individual, as Thanos was able to create a big enough portal to envelop him and his children to warp them out of the Statesman and later he warped Gamora alongside him to the Sanctuary II and Vormir, as well as that the portals also allows the wielder to influence the location the portal was opened to without directly warping there, as Thanos was able to use the Space Stone to send the Power Stone's energies to the moon without personally going there.
After the Infinity Gauntlet was completed and the Space Stone reached its full potential, alongside the other Infinity Stones, it allowed Thanos to kill off half of all life in the universe with a simple snap of his fingers even after he had been grievously wounded by Thor. The Space Stone's part in the genocide was apparently to allow the influence of the other Stones to affect the whole universe. However, using all six Stones in this manner at such a weakened state caused the Stones's combined power to nearly overwhelm him, and the Gauntlet and his left arm were left scorched by the release of energy.
- In the comics, the Space Gem was a purple Infinity Gem that increases the speed of its user and allows them to be teleported wherever they want. It was shattered alongside four of the other Infinity Gems, aside from the Time Stone, when the Illuminati tried to stop another universe from colliding with their own in the cosmic event of Secret Wars (2015). After the restoration of the universe, the Infinity Gems were recreated, with the Space Gem now being blue.