It is an intersting start.
The back of the ship with those large boxes on the sides could really be evened out to be less boxy.
Also you capture a very nice idea with this cross breaking apart the white and black but I think if you used more wedges to make the curving away from the frontal glass, you could put more emphasis on the glass, and less on the serrated edges. (If you do actually want serrated edges, I would recommend use of inverted corners or wedges yet again, as they look harsher and are more effective than just block building in cubes).
At the back your engines are sticking out a bit too much. Try to edit the white platform at top and bottom to be a bit more...impressive. Perhaps a different shape from just a plain 'ceiling-floor' idea. use of wedges and some asymmetrical designs would really help in that regard. Perhaps some flowing wedge line/pipe going across one line and connecting to engines?
The engines themselves with the cross is good. If you want a personal opinion I would make it have some wedges in the central area so that it looks like there are circles within the large blue compounds at the back. This is only for aesthetic benefit so not necessary if you feel it will not suit style.
Something like on this flag:
http://img03.deviantart.net/e1c7/i/2014/307/8/6/scotland_celtic_cross_flag_by_althistoryguy-d720uqt.png where you have circle around centre of cross.
Now the frontal 'tip' of the ship is quite nicely made with arc between the tip and the rest of ship. But this arc is inter-broken with lots of serrated steps. Use of wedges and other shapes could even this out and make it more pleasant to look at from below.
Finally the two boxes on ship above the logo to each side (small rectangular boxes with yellow lights)....I do not think they are necessary. Seem out of place.
To conclude: ship has lots of potential and with some additional use of wedges, corners, tetras (or slabs if you really want a contrast to be visible without wedges), you could make the ship even better. I look forward to re-reviewing the ship after it has been updated. Good luck!