Mind you, the Starship has the same internal volume, so they can replace it at the same time…..
https://www.nasa.gov/news-release/na...orbit-vehicle/
NASA Selects International Space Station US Deorbit Vehicle
…..NASA announced SpaceX has been selected to develop and deliver the U.S. Deorbit Vehicle that will provide the capability to deorbit the space station and ensure avoidance of risk to populated areas.
“Selecting a U.S. Deorbit Vehicle for the International Space Station will help NASA and its international partners ensure a safe and responsible transition in low Earth orbit at the end of station operations. This decision also supports NASA’s plans for future commercial destinations and allows for the continued use of space near Earth,” said Ken Bowersox, associate administrator for Space Operations Mission Directorate at NASA Headquarters in Washington.
“The orbital laboratory remains a blueprint for science, exploration, and partnerships in space for the benefit of all.”
While the company will develop the deorbit spacecraft, NASA will take ownership after development and operate it throughout its mission. Along with the space station, it is expected to destructively breakup as part of the re-entry process……