From the TV series.
It is a "Trans-Utopia Cruise ship Lines" luxury cruise liner.
It's name is Tulip
It had 4 baseball fields, 12 ball rooms and countless pools.
It is almost 200 years old and has changed hands numerous times which is why it is in such disrepair.
Currently only a small portion is habitable and has gravity.
There are two versions of the ship depending on which series it is in, Star Hunter or Star Hunter 2300.
The QJTUM is the original Tuilip from the first series and the Other one with the tower is from the second series.
No real explanation was given for the difference other then "refit".
At one point I had a model of the first one without all the damage but I have since lost it. Although it would be easy to recreate.
In the spirit of the show the new owner, i.e. the fleet, refitted her to handle Viper and Raptor operations.