Earth Spacedock or Spacedock 1 was a Federation space station facility in Earth orbit, built sometime prior to the year 2285. The station was built with a vast interior, in which numerous starships could be berthed for service and repairs, and was part of the Sol system's Starbase 1 complex of facilities. (TOS movie, novelization & comic adaptation: The Search for Spock; DS9 reference: Star Trek: Deep Space Nine Technical Manual)
Earth Spacedock, referred to simply as "Spacedock" was the largest Starfleet spacedock structure in near-Earth orbit. Other space-built structures might have been larger, but none was ever built as close to the planetary surface. It was originally conceived as a military base for ship repairs and refits. Spacedock orbited Earth just within the Van Allen radiation belts. The close proximity to the denser layers of Earth's atmosphere would normally cause the station's orbit to decay so it was fitted with massive impulse engines that maintained its orbit. The outer doors were at some point enlarged to fit ships as large as the Galaxy class starship.
Design, facilities and functionsEdit
Designed as permanent base for the many ships traveling the Sol System. It could easily provide refit and repair facilities for up to 8 cruiser-sized starships and up to 24 of Starfleet's lesser-sized ships.Although Spacedock was a vital link in Starfleet Operations and was administered by Starfleet Command, it was not an actual starbase. Being intended primarily as a military installation, it was originally designed to be equipped with 40 massive phaser banks, but the United Earth government objected to the presence of more weapons in Earth's orbit. A compromise was eventually reached and it was constructed weaponless, relying on high-powered deflectors. Nonetheless it retained its 40 weapon mounts, in case of interstellar war emergency, Starfleet Command can mount phaser weapons and have them operational within a single week. 
Another major purpose of Earth Spacedock was its ability to scan all of Solar space. The docking port became one of the central installations for weather-watch, debris-scan, radiation-flux analysis, and starship traffic control, for Sector 001. This was made possible by the largest single sensor array and subspace communications equipment known at that time. Antennae were placed at the top of Spacedock, which were so sensitive they could detect a meter-sized object in the Solar System's cometary halo, at least half a light year away.
In addition to its military and traffic control functions, Spacedock also became a commercial focal point for the Sol sector. Starfleet leases office space, warehouse facilities, cargo transporters, and trade arbitration for many of the more important commercial corporations. Because of its value as a trans-shipment point for both passengers and cargo, Spacedock also developed a thriving tourist trade. Its kilometers of wide halls were filled with shops, vendors, services and restaurant facilities catering to a wide range of races. It would eventually rival the Rigel star system as a source of revenue. What made this remarkable is that this commercial aspect of Starfleet's Repair and Service Facility had developed in a span of less than five years.
Earth Spacedock also provided the most extensive medical facilities in near-Terra orbit, rivaled only by those of the LaGrangian colonies in their completeness and scope of operation. The gravity of the station was entirely under the control of Starfleet engineers at any point in the station, so that the hospitals could be provided with any type of environment settings needed by species. The ongoing research being conducted here began to provide clues to the cures of many unsolvable medical mysteries. (Stardate Magazine vol. 1 (1984), Issue 1: "The Serpent Factor")
In the late 24th century, several classes of Starfleet starships were commonly built at Spacedock 1, including the Saber-class and the Norway-class. (DS9 reference: Star Trek: Deep Space Nine Technical Manual)
Earth Spacedock had become an auxiliary of Starfleet Headquarters, based in San Francisco. The wide variety of operations conducted at Spacedock made it an ideal training laboratory for Starfleet Academy. Cadets would get their first space experience there. No matter what branch of service the Cadet may eventually enter, the spacedock provided experiences related to almost every facet of Starfleet operations. Engineering cadets be exposed to towers of the facility's stabilizing impulse engine system and anti-matter reactors.
Because Starfleet provided security for the Spacedock, this gave on-the-job training in security and also familiarized the officer-to-be with the many different races that made up the Federation. The facility also provided great teaching grounds for Science, Medicine, Astrogation, and administration. (Stardate Magazine vol. 1 (1984), Issue 1: "The Serpent Factor")
By 2409, Spacedock served as the central hub of Starfleet Command and was under the command of Admiral Jorel Quinn, with Akira Sulu as second-in-command. (STO mission: "Welcome to Earth Spacedock") It was briefly a completely different design before Q Junior restored it to its classic look.