Air Command is the third branch of the GTU military, and is responsible for atmospheric warships, orbital defense emplacements on planets, and the great fortress bastions that guard the hyperlanes. While greatly reduced in size and authority compared to Land Force Command and Fleet Command, Air Commands position as the unit responsible for maintaining the space fortresses and planetary aerospace defense causes it to remain an integral part of the national council and the GTU's government. The Marshall of Air Command maintains the informal title of "Sky Marshall", a nod towards the influences of the 20th Century philosopher and poet Robert Heinlein on the way the GTU came to view the importance of its military and social structure.
Air Command was initially responsible for all space borne operations. It was at the direction of the first Sky Marshall, Saotome Ayashi that the Tyrum Warships wrecked in Earth Orbit were studied. Air command would also build Invicta Station, Earths first modern manufacturing and defense battle station which was placed in Solar Orbit. Air Command would produce the first in system defense warships and more importantly, the Hawking Class reconnaissance and research ships. The first hyperspace transit of a Terran ship would be the TUS Hawking, crewed by Air Command airmen and scientists.
Following first Contact with the Algan Republic, Air Command would construct Verdun Fortress and create a secondary defense force for the station that would come to be known as Ryans Raiders. It was at this point that the pirate rebellion spearheaded by a disgraced Air Command officer known as Romulus Chuck would occur. Chuck would seize control of 6 partially completed warships that had been earmarked to fortify the Algan Border and use them to try and launch a coup on Earth. His efforts failed and the Air Command "Home Fleet" would ultimately chase him down and destroy his ships over Alpha Centauri. The incident however happened at an inopportune time as the National Assembly and Council were debating how to redesign the Terran military to deal with the new realities of being an interstellar empire.
As a direct consequence of Chucks actions, Air Command would be stripped of control of the mobile fleet assets, which would instead be assigned to fleet command. Up until this point fleet command had been responsible for largely automated water borne craft, the great armadas of the Great Defensive War having long since been abandoned. The decision to grant them control of the space mobile assets was seen as a grievous humiliation for Air Command, but due to the perfidity of Chucks treason they were in no position to argue the point. Thankfully for their future standing the national council refused to give Fleet Command total control of all space assets. Much for the same reason Land Command maintained control of orbital infantry invasions for fear of giving the Admirals too much power (and thus risking another Romulus Chuck), Air Command was not stripped of its authority over the defense stations. As such Verdun, and later the great fortresses of Thermopylae, Gibraltar and Styx remained under the control of Air Command and the Sky Marshall, along with the massive wings of fighter aircraft assigned to them. Air Command would also be granted command of atmospheric defense aircraft on all colony worlds, and the Planetary Defense Artillery (PDA) placed on each GTU planet, just in case for some reason both Fleet and Land decided to work together for some treasonous goal. The theory being that at least one of the three primary branches should have some form of trump card on the other.
Air Command would go on to fight with distinction, and during the war in Heaven it's Pilots would fight a heroic campaign to maintain control of the Kerbol System and its gateway, as well as defend the great Styx fortress against the Unbidden at the Battle of Styx.