Nasa has studied various options for end-of-life disposal, external.
These include disassembling the station and using the younger elements in a next-generation platform. Another idea has been to simply to hand it off to some commercial concern to run and maintain.
But these solutions all have varying complications of complexity and cost, as well as the legal difficulty of having to untangle issues of ownership.
Neither Nasa nor SpaceX have released details of the design for the de-orbiting "tug boat", but it will require considerable thrust to safely guide the station into the atmosphere in the right place and at the right time.
The platform's great mass and extent - the dimensions roughly of a football pitch - mean some structures and components are bound to survive the heat of re-entry and make it all the way to the surface.
Controllers will allow the orbit of the ISS to naturally decay over a period of time, and after removing the last crew will command the tugboat to execute the final de-orbit manoeuvre.
Redundant spacecraft are aimed at a remote location in the Pacific known as Point Nemo.
Named after the famous submarine sailor from Jules Verne's book 20,000 Leagues Under the Sea, the target graveyard is more than 2,500km from the nearest piece of land.
Nasa is hopeful that a number of private consortia will have started launching commercial space stations by the time the ISS is brought out of the sky.
The focus of the space agencies will shift to a project to build a platform called Gateway that will orbit the Moon.