Rocket-powered VTOL is essentially a suborbital rocket which is not able to reach orbit. It does not look like a rocket, and is not an aircraft although it is built in the SPH. It resembles the real-life Lunar Landing Research Vehicle used in training US astronauts in the Apollo Program for Moon landing.
It uses an Mk1 Inline Cockpit as the command module, and uses radially-mounted Rockomax 24-77s for propulsion. It has 4 jettisonable FL-T400 Fuel Tanks, in which 2 of them are mounted radially using TT-38K Radial Decouplers and has Mk2-R Radial-Mount Parachutes. This means that the craft can either land using the rockets or by parachutes. The abort action group is set up to jettison all the fuel tanks and rocket motors, as well as deploy the parachutes in the event when the player screws the landing.
One possible usage is to train the player for landing a spacecraft in a celestial body with no atmosphere (such as the Mun), like the real-life LLRV.