Astral Queen

The Astral Queen is a FTL-capable former starliner now given over to transporting prisoners between worlds. At the time of the Cylon attack, she was originally said to be carrying 500 male prisoners (Miniseries) to their pardon hearings on Caprica (Bastille Day). However, this was later increased to a count of 1,500 prisoners. It was captained by Wilkens.

Following sabotage aboard the battlestar Galactica, which destroys the majority of the fleet's water reserves (Water), Lee Adama is sent to the Astral Queen to try and enlist the aid of the prisoners to help obtain fresh water supplies from an ice-bound moon (Bastille Day). However, once on board, he meets with the prisoners' spokesman, Tom Zarek, who orchestrates a break-out and hijacking of the ship.

The situation is resolved jointly by a marine assault from Galactica and by Lee Adama, agreeing to the core of Zarek's demands: that free and fair elections are held within the Fleet to appoint a new president at the end of Laura Roslin's term - some seven months from the date of the revolt on the Astral Queen. In return for his surrender and the assistance of the prisoners in obtaining the much-needed water ice for the fleet, Lee Adama leaves Zarek and his men in control of the Astral Queen, much to the chagrin of both President Roslin and Commander William Adama himself.

Notes

The ship is equipped with at least one "flare," launched upward from some point amidships and on the dorsal section. (The Farm)
The design and function of the Astral Queen is an acknowledgement of the original series, in which an identical design of vessel was defined as the Prison Barge.
In the DVD commentary for "Bastille Day", Ron D. Moore and David Eick say that in hindsight they feel that "Astral Queen" was a very poor choice of name for a prison ship, and they now wish they had used a different name.
It is possible that the Astral Queen is named for a transport mentioned in the original Star Trek episode "The Conscience of the King."