I've had this lying around for a while and just got around to rendering it.

Classic Space Transport Shuttle by Nice Try, on Flickr

Classic Space Transport Shuttle by Nice Try, on Flickr

C&C appreciated, especially with regards to greebling.

Looks good, though those engines may be a bit small.

Very nice! I love the curves!
Could we please have a shot of the inside?

Very nice. Has a bit of a Cosmic Fleet Voyager vibe.

I like the shaping around the cockpit and the intentional gaps you left between some of the curves and the tiles on top. Just the right greebliness, in my opinion.

The folding landing gear looks like it will work great. Maybe you have enough space there to add some skids or pads to the gear?  Here is a quick one-up-one-down shot of folding gear on a viper I built. These are based on hinge bricks and the skids are a bit fidly; so not exactly the solution for your excellent shuttle, but some kind of skid/foot that folds into the 1 stud wide layer on the bottom would add a lot, I think. 

Great work!

colours look great, details are a nice touch