The rocket exists of three stages. There is the first and second stage, and the lander. The shuttle is where the the crew lives and works. There are four seats for the commander, pilot, navigator, and engineer. There is a door connecting the crew areas (sleeping bags, galley, shower, etc.) to the cockpit. The airlock and crew entry hatch is under the right stabilizer. The second stage can be hollowed to fit a disassembled (will be crew-assembled in orbit) satelllite in.
Advantages to being multirole is that it can deploy sattelites (which are stored in a hollowed second stage), land on celestial bodies, or simply dock with a space station much like the shuttle of today.