As a hobby I like to draw and recently I have begun to draw the USS Hornet CV-12 (docked and open for tours at the former Alameda Naval base, home of the nuclear wessels). As I was researching her and her sisters I found that while they had relatively long life spans (Hornet herself was commissioned in 1943 and decommissioned in 1970), many of the carriers spent a great deal of their lives laid up or in reserve fleets. (Again Hornet was mothballed from 1970 until being released as a museum in 1998). This got me thinking: was USS Enterprise actually commissioned and active for all of her roughly 40 years (barring rebuilding times)? Of all the Star Trek Enterprises, hull 1701 seems to have had the longest life. I understand that Enterprise CVN-65 was active continuously from 1960 until her 2013 decommissioning , although this may be an exception. My answer is no and I've compiled a rough outline of what her history might have been like: (please feel free to disagree). 2245-most sources agree this is the date of the ship's launch. Assuming that a launch date is the same as it is in ocean going vessels, this does not assume that the ship was ready for service in 2245. I give the ship about a year and a half fitting out period, putting her ready for commissioning in 2247. 2247-Robert April overseas her trial runs and early missions, beginning her first five year mission. 2253-Enterprise is laid up for the first time. Having traveled thousands of light years in five years with the assumption that the ship returned to earth no more than once, it was overhauled minimally at different starbases, but was not given a full refit. As newer Constitution class ships entered service, Enterprise and her outdated components were not seen as needed. Alternatively political events may have cooled and much like the US Navy's Essex class carriers there was no need for such a large fleet of ships at the time. 2253-2258-Enterprise laid up 2259-Enterprise reactivated. The high number of hull losses meant Starfleet needed to reactivate older ships. An upgrade and overhaul of systems brings the ship up to date and Christopher Pike takes Enterprise out on her second five year mission. 2259-2264-Pike's five year mission (Cage events take place near the end of the mission) 2265-Enterprise returns for a minor overhaul and returned to Service under Captain Kirk. At this time the ship is 20 years old and Starfleet is considering the future of the class. The last new build Constitution sub classes are commissioned (Defiant namely) with improved systems. A replacement capitol ship (unknown) is rejected and Starfleet forges ahead with the Excelsior program. Tensions with the Klingon Empire prompt discussions of continuing the life of the Constitution class. 2265-2270-Kirk's five year mission 2270-Enterprise puts in for her first major refit that sees the ship radically altered. 18 months later, in late 2271 she reemerges a new ship. 2271-2276-Kirk's second five year mission 2276-Following Enterprises first five year mission as a "new" ship Starfleet decides to lay her up again. New builds render her obsolete. The crew is dispersed, etc. 2281-Starfleet recommissions Enterprise as an advanced training ship. Her automatic weapons controls are largely removed (thus we see manual torpedo loading in TWOK) and her interior is reconfigured for training cruises. 6 months of every year the ship takes a group of cadets out on deep space training. It is during one of these routine missions that the ship is called into action against a renegade ship and nearly destroyed. Starfleet makes the decision to decommission the ship, which is now 40 years old and outclassed by the newer Excelsior, her replacement. We know the rest of the story: Enterprise is never allowed to be decommissioned and is instead destroyed in battle.