Print, print and then print some more!
Tallest piece is about 115mm and the launch pad takes up nearly the entire build platform of a Thing-O-Matic.
Printed with a layer height of .25mm, 0 extra shells and 10% infill. You may want to print the launch pad with extra shells to increase the strength of the posts.
Each of the main parts, the Orbiter, boosters and fuel tank are comprised of three pieces each which are pinned together using bits of 3mm filament and glued. Gluing is optional, but recommended. I use acetone.
Attach the Orbiter to the fuel tank using 3mm filament. If the filament fits too loosely you can crush it slightly with pliers to make it wider. Attach the boosters to the fuel tank in the same manner.
The engine piece snaps into the back of the Orbiter and the nozzle pieces for the boosters press into place. A bit of sanding may be needed depending upon how flared out the bottom gets printed.