Graymalkin began as the time-traveling mutant soldier Nathan Dayspring's orbital space station, named after the address of Xavier's School for Gifted Youngsters. In Nathan's time, a group of freedom fighters, Askani, deified the ancient X-Men and "the Xavier" became a father figure. After the Neo-Canaanites defeated the New Canaanites, Nathan learned that Stryfe used the Tinex and, with the A.D.A.M. Unit Zero, fled, traveling back in time to the late 20th century. 
As part of his mission as the Askani'son, Nathan returned to the 20th century to foil the plans of Stryfe and preserve Apocalypse's rise to power. Cable stationed Graymalkin in Earth's orbit, as a headquarters. Cable's Celestial A.I., Professor had assumed control of Graymalkin.
Graymalkin had complete control over every part of its structure and could fashion rooms, weapons, and vehicles as needed from various storehouses and parts it had. It was able to design and run training programs for Cable, as well as make living quarters and workshop areas for him. Graymalkin not only served as a base for Cable, but also allowed Cable to teleport through time and space, with the time displacement core (TDC). Cable simply had to command Professor to "Body-Slide" him to a destination, which served as Cable's mercenary team Six Pack's chief means of transportation.
On Graymalkin, Cable had robot servants that he named after the original X-Men. After being betrayed, by "Domino", Cable teleported the both of them on Graymalkin and asked Professor to retrieve X-Force, the former members of the New Mutants, but he was unable, due to the high electromagnetic signatures surrounding them. At one time, Cable teleported Wolverine and Bishop on-board, while they were attempting to learn the location of Stryfe, who had attempted to murder Professor Charles Xavier and kidnapped Cyclops and Jean Grey.
After hearing a report of the discovery of an orbital ship, X-Force immediately believed it was Graymalkin and wanted to get to it quickly to try to salvage what they could from it. Upon their arrival, Professor immediately greeted Cannonball, who recognized Professor's voice as "Ship". Cannonball inquired Professor's origins, but Professor remembered nothing of his past as Ship. While X-Force was searching around Graymalkin for weapons and resources, Nick Fury, agents of S.H.I.E.L.D., and War Machine tried to investigate it for whereabouts on Cable. The two groups began to battle and, after the damage began to override the security systems, the base began to lose power and defenses. At that point, Professor announced that emergency measures were being taken and a destruct sequence had began. After Professor announced that his self-preservation scan was completed, he teleported both Sunspot and Cannonball to the command center of the ship and told them that they must begin jettisoning portions of the ship, to conserve power to the main core before the destruct sequence ran out. Professor stated that Cannonball was the only one other than Cable that could turn-off the sequence. Cannonball and Sunspot began to dump parts of Graymalkin all over the world, sending the weapons depot and the cargo bay to their Camp Verde base, and learned that the TDC was taking up the largest power. Knowing that if Cable ever did return, he would need the TDC, Cannonball did what he was trained to and sent it off to the deepest portion of the Pacific Ocean. At that point, a majority of Graymalkin exploded, but Professor faked its destruction, by keeping the remaining parts, including its core, cloaked to hide itself.
Magneto discovered the abandoned space-station, deactivated the Professor, and used the Shi'ar technology stolen from his time with the X-Men to expand it with pieces from his older space station, Asteroid M, naming it Avalon. Avalon was destroyed by a battle between reality jumper Holocaust and Exodus.
- The first appearance of Graymalkin is arguable, as Cable was seen teleporting to a mysterious, technologically advanced private retreat without identifying where he arrived. It's conceivable the location he traveled to in X-Force #8 was one of his Earth-based safehouses, like the Swiss chalet. It was first confirmed Cable had an orbital base in X-Force #15.
- 17 appearance(s) of Graymalkin (Space Station)
- 1 minor appearance(s) of Graymalkin (Space Station)
- 6 mention(s) of Graymalkin (Space Station)
- 2 image(s) of Graymalkin (Space Station)