At the end of June, the US National Aeronautics and Space Administration selected Elon Musk’s company SpaceX to develop and build a spacecraft (the US Deorbit Vehicle) designed to safely deorbit the International Space Station after the end of its service life.

Plans to dispose of the aging orbital station have been in the works for many years: NASA proposes to retire the ISS early next decade, but not everyone is happy with that prospect.

Jean-Jacques Dordin, who was director general of the European Space Agency when the station was built, and former NASA administrator Michael Griffin argue that the ISS’s service life should be extended and that SpaceX spacecraft should not be used to bring it up. Instead, they argue that the ISS should be lifted into a higher, more stable orbit, where the space outpost could operate for decades before its fate is determined by future generations.