 The U.S. de-orbit vehicle will use a previously flown SpaceX Cargo Dragon capsule, which is used to deliver supplies to the station. But this specially designed vehicle will have six times more propellant. That's because it has to help steer the massive space station out of orbit and point it towards a controlled reentry through the atmosphere and safely into the ocean. NASA and SpaceX say the process to de-orbit the station begins with a more than year-long drift down into the atmosphere before getting a final shove out of orbit from the vehicle's multiple engines.