The Galaxy class was developed to replace the aging Ambassador and Oberth class starships as Starfleets primary exploration vessel. The design was initiated in 2343 with a highly challenging specification which called for a ship based on the Nebula design then being developed, but equally capable of scientific, exploration, diplomatic, cultural, and combat roles all within a single multi-mission hull. In fact, many came to regard the requirement as too challenging; the project suffered from numerous delays due to a wide range of design, manufacturing, and construction problems. The first of the class, the USS Galaxy, was launched in 2357 and commissioned in 2362, nearly two decades after initial approval. The USS Galaxy which emerged from the Utopia Planitia shipyard had very similar lines to the Nebula class. The Galaxy is some 15% larger in volume, although its less compact design gives it considerably greater length than the smaller vessel. The major change between the two is the lack of a mission specific pod on the Galaxy class, the increased volume allowing sections within the hull to be mission customized. This combined with a more advanced systems level to allow all functions to be performed by the single design. In addition the saucer and engineering hulls are separated by an eleven deck connecting neck section. This separation between the two hulls allows the nacelles to be located outboard and above the engineering hull, a position which increases the efficiency of the warp drive field slightly. This gives the Galaxy class warp coils an efficiency of 88% at speeds of up to Warp 7 and 52% through Warp 9.1 - the comparable figures for the Nebula class are 84% and 47% respectively. The Galaxy class has a life expectancy of 100 years.
