Defiance Class Heavy Cruiser

Defiance Class Heavy CruiserSeries classification: CA
Notable Ships: 
* UNSC Kindred Defiance
* UNSC Vae Iridictus
* UNSC Moscow
* UNSC Kindred Spirit
* UNSC Heart of Valour
* UNSC Spear of Winter
* UNSC Chicago
Ships Produced: 12 [20 planned, 3 cancelled, 7 never started]
Production years: 2537-2542
The Defiance class experimental heavy cruiser was an early attempt at integrating alien technologies into naval vessels of the UNSC, although all attempts at such failed. Never the less, it was an astounding success with its first ship ever built, the UNSC Kindred Defiance. Due to dwindling resources and being costing almost as much as some dreadnoughts, only a few ships of this class was ever produced, with several having construction halted or cancelled. 
Three Defiance Class heavy cruisers survived the Human covenant war and continue to serve in the UNSC Navy Reserves.
OVERVIEW AND RECORD
Defiance Heavy cruisers were mostly tasked with dangerous operations in covenant space, deployed to wreak havoc, and map out hostile territories for future possible counter assaults.
Two ships were destroyed on such missions with another going missing. Two more were destroyed in the late 2540's. Five others were Destroyed or went missing in action during the fall of reach and tribute. The last two taking part in the defense of Sol. One of the ships lost at Reach managed to straggle home to Earth 2 months after the Battle of Earth concluded.
The designs and service data collected from these warships proved vital in the creation of several new cruiser and dreadnought classes in the post war era. All three ships were refit to make use of energy shielding in 2556.
A Defiance II Class Heavy Cruiser was in the works until being postponed due to the uprising of the created.
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Ships Produced:
Construction started, date finished/cancelled and status as of 2554:
UNSC Kindred Defiance CA-1049 (2537) MIA
UNSC Moscow CA-1055 (2537) KIA
UNSC Kindred Spirit CA-1057 (2538) MIA
UNSC Vae Iridictus CA-1059 (2538) Active
UNSC Chicago CA-1060 (2538) KIA
UNSC Heart of Valour CA-1061 (2538) KIA
UNSC Spear of Winter CA-1063 (2539) Active
UNSC Defiant Hand CA-1062 (Delayed / 2539) MIA 
UNSC Romania CA-1059 (Delayed / Canceled (2539))
UNSC Lone Star CA-1066 (Delayed / 2540) KIA
UNSC Harvest CA-1069 (Canceled (2540) (May have been finished in secret by ONI)) 
UNSC Colonial Star CA-1071 (2540) KIA
UNSC Far Horizon CA-1072 (Canceled (2541))
UNSC Final Defiance CA-1077 (2541) KIA
UNSC Titans Hand CA-1079 (2542) Active
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Never Started
UNSC Sovereignty CA-1059 (Planned 2552)
UNSC Solace May CA-1080 (Planned 2552)
UNSC Bermuda CA-1081 (Planned 2552)
UNSC Virtute Finis CA-1076 (planned 2552)
UNSC Jupiter CA-1078 (Planned 2543)
UNSC O'Donnell CA-1073 (Planned 2542)
UNSC Lincoln CA-1074 (Planned 2542)
UNSC Summer Dawn CA-1075 (Planned 2552)