||This television-related article describes an aspect of the series in a primarily in-universe style. Please help rewrite it to explain the fiction more clearly and provide non-fictional perspective.|
- This article deals with the Space Station Io, as presented in the science fiction universe of the television show Babylon 5.
- For the real astronomical object named Io, one of the four Galilean moons of Jupiter, see Io.
The transfer point on Io is a fictional outpost in the Babylon 5 universe, constructed by Earth Alliance since the primary jumpgate of the Sol system orbits the moon. Space Station Io also orbits nearby; the base is second in size only to the Earth Alliance colony on Mars, and is the one most generally used by EarthForce. Similar in some ways to the station Babylon 5 itself, Io functions both as a civilian and military way station for most out-of-system traffic, especially those ships too small to have their own jump engines. The area is always heavily patrolled since any damage to the jumpgate could cripple or seriously harm Earth's interests.
- "Yes, this is the primary jumpgate for Earth. It's positioned at Io (most of the base is actually in orbit outside Io, some of it on the surface, as we showed in "Chrysalis") to keep Earth a bit safer by removing it some distance, and because putting it near the huge energy field of Jupiter makes it more difficult for weapons to target it from a distance. It's mainly a tactical decision."
- -- posted by J. Michael Straczynski (JMS) on America Online 96-03-27 04:20:09
Travel time Edit
To outside observers, it takes three days in hyperspace to travel from the jump gate near Babylon 5 to the jumpgate near Io.
- "Three days is the time to the jumpgate off Io. Once you're within our solar system, it takes another several days or more to reach Earth itself. It's fairly common to keep your jumpgate a bit removed from your "core" planet so you have warning if any aggressors come out of it."
- -- posted by JMS on CompuServe Date: 22 Aug 1996 12:28:18 -0700
According to some sources Earth Force constructed the jumpgate at Io in 2198 and deactivated the Centauri jumpgate (built in 2156) in Earth orbit, due to Earth Alliance security concerns.  Unlike the cylindrical Babylon-series of space colonies, the few times we've glimpsed the Io station (Such as in "Chrysalis") the station is clearly shown to be in the shape of a large wheel.
Earth-Minbari War Edit
As the Earth-Minbari War neared its final conclusion in 2245, Earth did lose all contact with her colonies, including Io, before the Minbari fleet bypassed Mars and jumped straight to Earth at the Battle of the Line. However, it is unclear whether Io was actually destroyed or merely had its communications and defences disabled. Regardless, it is clear that Station Io is fully functional at the end of 2258.
On December 31, 2258, Station Io was the site of an official visit from President Luis Santiago prior to departing on a goodwill tour of the outer planet colonies. According to Interstellar Network News (ISN) at the time, "sources close to the president have hinted that he'll give a major policy speech New Year's Day from the jump point on Io. The speech is likely to concern human-alien relations over the remainder of his five-year term."
At the same time, a shipment of jammers set to broadcast static at a location near Io was discovered on Babylon 5 by Security Chief Michael Garibaldi just before he was shot in the back. He was able to warn Commander Jeffrey Sinclair only as he lost consciousness, but there was not enough time to warn the president that he might be in danger.
Just as it was about to dock with Space Station Io, the president's transport, EarthForce One, was utterly destroyed by a massive explosion, killing President Santiago along with many others. The explosion was broadcast live across the galaxy on ISN, who reported that Vice President Morgan Clark had previously disembarked "suffering from a viral infection, and had been hoping to catch up with the tour as it returned from Io." According to show creator J. Michael Straczynski, Chief of Presidential Security Lianna Kemmer also survived since "she would've been handling the advance work on Io prior to Santiago's arrival." 
Susan Ivanova had served under John Sheridan for a time at Station Io prior to 2258. He had great respect and professional admiration for her, and they quickly became friends again once they were reunited upon his assignment to Babylon 5 as commander.
Some unverified sources suggest that Sheridan took command of the EarthForce base on Io at the conclusion of the Earth-Minbari War in 2248,  and was transferred in early 2251 after helping to suppress the Martian Food Riots. Sheridan met and married Anna Sheridan in 2249 on Io. The same sources suggest that after graduating from Officer Training School in 2249, Ivanova was posted to Io in 2250 where she worked with Sheridan for the first time. She was then transferred from Io to Earth in 2253. 
In 2259, General Richard Franklin used the official story that his 25,000 EarthForce troops arriving on Babylon 5 were traveling on to Io to cover the fact that they were really being deployed on Operation Sudden Death to attack the rebel stronghold at Matok, on the planet Akdor in the Sh'Lassen Triumvirate, at the request of the Sh'Lassen government.
In mid-2260, the transfer point on Io was again in the news when President Morgan Clark declared martial law, ostensibly because of the nearby confrontations between the insane Shadow battlecrab discovered on Ganymede, Sheridan's White Star, and the EAS Agamemnon ("Messages from Earth").
Shortly after, Io became the scene of the first space battle in the Earth Alliance Civil War when five rebel EarthForce ships led by General William Hague attempted to flee the Solar system via Io's jumpgate, but were ambushed by a superior force loyal to President Clark (including the EAS Schwarzkopf  and EAS Excalibur ). Three of the rebel ships were destroyed (or four according to ISN).  After disabling or destroying their pursuit, the two surviving ships, including General Hague's flagship EAS Alexander continued onwards to a rendezvous at the Orion 7 Earth colony.