|Featured In||Skyward (series)|
Alta Base is a military outpost on the surface of Detritus, directly above Igneous Cavern. It is the primary DDF base, until the Defiants reclaim several of the planet's orbital platforms and establish Platform Prime.
Alta Base sits over 120 kilometers west of a mountain range. Anti-aircraft (AA) guns protect the base, with a comfortable range of 75 meters and a maximum range of 120 meters. The area around Alta Base has been turned into farm land.
It contains the only trees on Detritus.
Flight school is located at Alta Base, with cadets training and living at the base. Cadets are housed in the same buildings as full pilots and share facilities with these pilots. Some of the facilities include mockpits, a mess hall, bedrooms, and bathrooms. Spensa is denied lodging at Alta Base during her time as a cadet, and instead stays in the nearby cave that houses M-Bot.
Public elevators are available to take people to Igneous Caverns about 200 meters from the base proper, however, they are quite slow and prone to breaking. In comparison, it is possible to travel from Alta Base to the deep caverns in less than five minutes, although the journey normally takes closer to fifteen.
On duty DDF pilots live and work at Alta Base and are rotated down into the deep caverns at different intervals in order to protect some of the DDF forces in the case that Alta is destroyed by a lifebuster. If a lifebuster is dropped directly on Alta Base it would also destroy Igneous Cavern.
Civilian housing makes up a town within Alta Base, filled with homes for the farmers of the land past the base, as well as shops.
Private hangars, near the public elevators, allow rich citizens such as Jorgen Weight to park hovercars while they visit the base.
In the beginning, Alta Base had been cloaked to hide it from the Krell, in an attempt to build up a defense force against the aliens using ship factories in Igneous Cavern. The Krell, however, discovered the base and sent a large force to attack and destroy the humans. The DDF won the Battle of Alta, chasing off the Krell and saving Alta Base. Following the battle they removed the cloaking from Alta Base and further fortified their position.
The Battle of Alta Second took place on the day of Skyward Flight's graduation. Admiral Ironsides sent the entire fleet of the Defiant Defense Force to a falling shipyard to recover its acclivity rings, leaving the base vulnerable. As expected, the Krell attack the DDF ships, attempting to destroy the shipyard and acclivity rings. This attack, however, was a diversion planned by the Krell so they could gain an opening to directly attack and destroy Alta Base. A second force of Krell, including a lifebuster, went to attack Alta Base while it was undefended. The force broke through Alta Base's exterior defenses where a falling lifebuster from the other battle had destroyed anti-aircraft gun outposts forty-six through forty-eight. Spensa defended the base in a damaged Poco by anticipating the movement of the Krell using her cytonic abilities. Spensa's ship crash-landed before she is able to take down the lifebuster. Cobb, piloting M-Bot (who had rewritten his code to allow another pilot to fly him into combat), found Spensa and gave her control of M-Bot so she could rejoin the battle. When the lifebuster dropped its bomb, Spensa dives towards it and uses her light-lance to pull it safely away from Alta Base and Igneous Cavern. Just before its detonation, she used her cytonic abilities to hyperjump M-Bot outside of the blast radius. 
Skyward · Starsight · Cytonic · Skyward 4
(Defending Elysium · Sunreach · ReDawn · Evershore)
|Characters||Spensa · M-Bot · Doomslug · Jorgen · Cobb · Kimmalyn · FM · Rig · Hurl · Nedd · Arturo · Ironsides · Morriumur · Vapor · Hesho · Brade · Cuna · Winzik· Jason Write|
|Groups||Varvax · Figment · Kitsen · Dione · Delvers · Skyward Flight · Defiant League · Defiant Defense Force · Superiority · KRELL|
|Places||Detritus · Igneous Cavern · Alta Base · Flight School · Starsight · Platform Prime · Nowhere · Earth|
|Other||Cytonics · Lifebuster · Human Wars · Battle of Alta · Battle of Alta Second · Phone Company · Cytoverse|