The name Melbourne has a longstanding history as a ship name, from steamships in the 19th Century through naval vessels of the 20th and 21st. The United Federation of Planets has continued the tradition with a succession of Starfleet vessels bearing the name.
The HMAS Melbourne started out as the HMS Majestic, lead ship of a new class of aircraft carrier constructed by the United Kingdom for the Royal Navy at the end of World War II. Following the war, Australia purchased the vessel in 1947 and she was commissioned as HMAS Melbourne in the Royal Australian Navy (RAN) in 1955. Though peripherally involved in several conflicts in Southeast Asia during the 20th Century, HMAS Melbourne did not engage in direct combat operations. The HMAS Melbourne was, however, the only Commonwealth naval vessel to sink two friendly warships in peacetime collisions. Though neither collision was determined to be her fault, it did lead to a belief that the ship was jinxed. Showing her age after three decades, HMAS Melbourne was decommissioned in 1982 before being sold for scrap in 1985. A new HMAS Melbourne (FFG 05), a guided missile frigate, was launched four years later and served in the RAN into the early 21st Century.
The first USS Melbourne commissioned in Starfleet was a Walker-class cruiser. The Walker class and its contemporaries were developed at the turn of the 23rd Century, part of Operation Next Step to produce a new generation of starships and the first effort to truly fully leverage and combine the technical expertise of multiple Federation members, with the previous generation leaning heavily on Earth design principles. Like the other vessel classes that came out of Operation Next Step, the Walker class was notable for its angular warp nacelles derived from Andorian designs rather than the cylindrical nacelles common on Earth-designed starships. The USS Melbourne was primarily an explorer, spending over two decades helping to expand the Federation frontier and being involved in the discovery of a dozen new intelligent species, several of which would go on to become Federation members. Aging technology made the USS Melbourne mostly obsolete by the end of the 2240s and she was scheduled for decommissioning before being called back to active duty by the outbreak of the Federation-Klingon War in 2256. Assigned to patrol duties, the USS Melbourne was destroyed in 2257 during a Klingon attack on Starbase 1.
The second USS Melbourne was a Constellation-class cruiser launched in 2312. Initially designed in the mid-2280s, the Constellation class was intended for a combat-centric role as an interceptor, using its rare four-nacelle warp engine design for rapid response. The deescalation of tensions with the Klingon Empire due to the Khitomer Accords led to a change in the Constellation's mission profiles, turning its capabilities to deep space exploration and rapid defense and emergency response duties. The USS Melbourne undertook exploration missions, mainly in the Beta Quadrant, which also led to occasional hostile confrontations with Quadrant powers like the Romulans and the Gorn. After three decades of operation the Melbourne was decommissioned in 2344, but was stripped of classified technology and sold to a civilian owner. Renamed as the SS Bucephalus, she is still flying today as a deep space freighter supplying far flung colonies in the Alpha Quadrant.
The next USS Melbourne started life as the Excelsior-class USS Halcyon (NCC-16358), launched in 2319. The Excelsior class ships have been the workhorses of Starfleet for nearly a century, only recently being succeeded by a new generation of ships, including the Excelsior-inspired Obena class. The Halcyon served primarily as a diplomatic vessel, ferrying ambassadors, diplomats and negotiating teams from one end of the Federation to the other. When the then-new California-class starships began taking over these types of duties in the early 2350s, the USS Halcyon was decommissioned and mothballed. She did not remain retired for long, however, as an increasing demand for starships led to her being pulled from storage and recommissioned as the third USS Melbourne (NCC-52648) in 2359. She served in an auxiliary support role until 2366, when she was again scheduled for decommissioning ahead of the commissioning of a new Nebula-class USS Melbourne. This never happened, as the older USS Melbourne was called to duty as part of the hastily-assembled fleet sent to Wolf 359 to intercept a Borg cube that was on a course for Sector 001. Of the 40 ships that made up the fleet, 39 were destroyed, including the Excelsior-class USS Melbourne as well as its Nebula-class successor, which had been rushed into service to reinforce the fleet.
The immediate predecessor to the current Parliament-class USS Melbourne had a short life. The USS Melbourne (NCC-62043) was a Nebula-class starship, intended for deep space exploration missions. She eschewed the standard rear-mounted sensor platform or torpedo launcher commonly found on other Nebula classes for an auxiliary warp engine module that mounted two additional smaller warp nacelles powered by a secondary warp core to increase the ship's speed and range. As the new USS Melbourne was completing construction and commissioning at the San Francisco orbital shipyards at Earth, she was offered to Commander William T. Riker as his first command. Riker declined the offer, preferring to remain as the First Officer of the Federation flagship, the Galaxy-class USS Enterprise-D. Before a new captain could be selected, the new USS Melbourne was rushed into duty to reinforce the fleet being assembled at Wolf 359 to confront a Borg cube heading for Earth. Also part of this fleet was the older, Excelsior-class USS Melbourne (NCC-52648), scheduled to be decommissioned ahead of the new ship's official launch. Under the temporary command of Captain Thomas Halloway, the Nebula-class USS Melbourne was one of the 39 ships destroyed in the Battle of Wolf 359, as was her predecessor. The presence of two USS Melbournes at the battle has led to some confusion, especially as hull damage often causes the two vessels's hull registries to appear to be identical numbers in some low-resolution images of the wrecks.