Soyuz Fregat Rocket
1,5 years in the making (counting the weeks I had no time to build) and dozens of bricklink orders makes this the largest and most time consuming Lego project I've ever finished. I started the build with the side boosters which were the trickiest part, then made the central booster and the third stage with the Soyuz capsule.
The rocket is 155,8 studs long (about 1,25 m or 4,1 ft) and is about 5,5 kg heavy. The stages can be separated and inside the third stage of the rocket there is space for a Soyuz capsule. The structure of the rocket is sturdy enough for lifting the rocket holding only from the third stage.