Rotate the model in Slic3r so the rocket is upright for printing. The example was printed on an Orion with 1.75mm T-Glase, using .6mm nozzle setting (actual nozzle is .5mm), .5mm layer height, .6mm extrusion width, 10mm/s speed, spiral vase mode, zero infill, vertical shells perimeters (min) = 1, 220 degrees temp on the extruder, 60 degrees on bed.
When you print with T-Glase this way, it is fairly transparent because it is hollow with walls that are .6mm thick. If not rescaled, the rocket is about 5.5 inches tall.
With .5mm layer height, this model is only sturdy enough to be a display model, not a flyable rocket. Any defect that occurs while printing becomes a weak area where the layers can separate if stressed.
You can print it at .2 mm layer height to get more strength, but it loses a lot of it's transparency. Or you can print it with more vertical shell perimeters, but you then have to turn off the spiral vase mode and you get visible seams where it changes Z.
If the tip ends up a bit wiggly, it can easily be straightened up with an x-acto knife.
UPDATE: 4/6/2015 - Added RocketForMegaScaling.stl. This fixes an issue some people had where scaling the rocket to larger sizes would cause Slic3r to create a tiny cylinder along the axis of the upper part of the rocket.