Space Jump

The Space Jump (スペースジャンプ Supēsu Janpu) is a highly advanced Chozo-designed movement system. It is an ancient upgrade for the Power Suit and is chronologically first discovered by Samus Aran during the events of Metroid: Zero Mission.

Variations of it exist in the Space Jump Boots, High Jump Boots, and Jump Boots.

Functionality
The Space Jump is a highly advanced movement system that gives the Power Suit the ability to continually Spin Jump in the air. The Spin Jump generated by this upgrade is extremely quick -- Samus's crouched appearance during these jumps is blurred due to the extreme speed at which she is spinning. Samus can scale any height with this upgrade, and in combination with the Screw Attack, this upgrade becomes a deadly weapon.

3-D appearances
The Space Jump appeared as Space Jump Boots in Metroid Prime, Metroid Prime 2: Echoes and Metroid Prime 3: Corruption; the Space Jump Boots merely gave Samus a double jump instead of the infinite mid-air jump given by the original upgrade. The functionality of the original Space Jump is somewhat retained in the Screw Attack in Metroid Prime 2 and 3, which allows Samus to make a total of five mid-air jumps. Metroid Prime Hunters included the Jump Boots as a starting ability, allowing for a single mid-air jump if the player walks off of an edge. Samus has a maximum of two mid-air jumps in the Super Smash Bros. series (if her Up-B attack, the Screw Attack, is also used).

In Metroid: Other M, Samus is capable of limitlessly jumping in mid-air but is unable to gain altitude like she could in the 2D games. However, it does slightly increase Samus' jumping, in that it functions somewhat like the Hi-Jump Boots.

Metroid II manual
"With this item Samus can jump continuously through the air while spin jumping. Learn how to use this item effectively by hitting the jump button again before she touches the ground and Samus will be able to do a perpetual jump. It may require some practice, but keep trying!"

Super Metroid manual
"With the Space Jump Boots, Samus can jump continuously in the air and fly through open areas. To operate this item, press the jump button just after Samus peaks in a somersault jump."

Metroid Fusion manual
"Perform consecutive Spin Jumps. With practice, it's possible to use the propulsion to "fly"."

Zero Mission Samus Screen data
"Somersault continually in the air. Use A mid-somersault to jump again."

Metroid: Other M manual
"Press 2 during a spin jump to perform another spin jump. Note: If you continue to press 2, you will continue to space-jump. "

Metroid: Other M Samus Screen data
"Effect: Lets Samus do consecutive spin jumps. Controls: While spin-jumping, press 2 repeatedly ."

Trivia

 * In Super Metroid, Samus can still Wall Jump after obtaining the Space Jump. In the modern 2D games, Wall Jumping is disabled when the Space Jump is obtained. This could be because after the Space Jump is obtained, there is no need for Wall Jumping.
 * Despite radical differences between suits, Samus' Space Jump sprites in Metroid Fusion are reused in Zero Mission (obviously redone in a different pallete).