The Zero Suit is a form fitting bodysuit of Chozo design worn by Samus Aran in combat. Its main purpose is to materialize and store her Power Suit at will as well as providing minimal protection. It is known to be composed of a highly advanced and flexible material that allows her to move freely and quickly so as not to hinder her acrobatic movements.
Zero Suit BasicsEdit
While Samus Aran primarily utilizes her Power Suit on missions, she uses her Zero Suit at the same time since it is usually her only means of accessing the Power Suit's abilities. In earlier games, she was shown wearing more casual clothing underneath the Power Suit. It made its first true debut in Metroid: Zero Mission; where after crash landing back on the planet Zebes due to a Space Pirate ambush, she lost the ability to materialize her Power Suit and was forced to travel across the surface in only her Zero Suit. After facing the Ruins Test Samus regained the ability to summon her Power Suit though in a much stronger form. It has gone on to appear in every title since, usually in a special ending scene as a reward for completing certain tasks in the game.
Storage and Materialization SystemEdit
The Zero Suits ability to store and construct Samus Aran's Power Suit when she so chooses implies it is a kind of biological supercomputer. This bio-computer is then linked to Samus's neurological network allowing her to control its powers. With this she can form her Power Suit from the three Chozo Symbols that are located on her chest, back and left hand; being easily distinquised from rest of the Zero Suit. When activated the symbols begin to glow before materializing the physical properties of the Power Suit around her body; thus allowing her to switch back and forth at will.
The Chozo symbols appear to be the most important part of the suit as they seem to act as conduits that allow the energy from within Samus to manifest directly into physical form via her thoughts. Since this process requires utmost concentration mentally, Samus was trained by the Chozo to control her emotions so as to stay perfectly calm. Feelings of intense emotion cloud not only her judgement, but her ability to concentrate with the immense strain of activating her Power Suit.
Being unable to do so results in her Suit immediately dissipating leaving her vulnerable to attack; an event that has only occurred twice, both against her most hated nemesis Ridley. It is greatly implied that normal humans could not handle the amount of stress that this process requires and only through her Chozo DNA infusion and rigorous training was she able at last to accomplish these abilities. As Samus was about to enter Sector Zero, she was shot in the back by Adam Malkovich to temporarily deactivate her Power Suit and leave her unable to stop him from entering Sector Zero. The emotion she feels causes her Power Suit to fluctuate as she attempts to reactivate it before Adam enters the sector.
Defensive Properties and AbilitiesEdit
As previously stated, the Zero Suit's primary function is to allow use of the Power Suit. In emergency situations, the Zero Suit also provides relatively minor defense to Samus from injury and attack. The unknown material it is composed of seems to be nearly indestructible, as it is never seen to be torn by any kind of impact or strike. However, it ultimately provides very minimal protection against enemies, most likely due to the fact that it is linked to Samus neurologically, thus acting much like a second layer of skin. This added ability of the Zero Suit works the best when it molds with that of the Power Suit, essentially becoming the lowest layer of the suit itself.
Since the Zero Suit is in its very basic sense the controlling computer for Samus's Power Suit, it is also unable to alter or absorb any weapon systems incompatible with Chozo technology- namely technology that is too advanced (a rarity),or too archaic or obsolete by Chozo Standards. In situations when it malfunctions Samus must use her exceptional combat skills and Paralyzer that she keeps holstered on her at all times. The lack of additional fire power may have been the reason she wore a much larger harness over her Zero Suit during her early years as a Galactic Federation Officer. The seeming inability or difficulty of her suit to analyze the Galactic Federations weapon systems (which by Chozo standards is much less advanced) may have prompted her to wear GF equipment that she likely handled on a much regular basis.
Its true value lies in allowing Samus to freely move around without the added weight and size of the Power Suit to slow her down. This allows her to use her super-human reflexes and skill to easily outpace most opponents that would attempt pursuit. Overall, the Zero Suit is an integral part of Samus Aran's abilities.