Russia’s mission control center will adjust the ISS orbit by switching on thrusters of Europe’s Europe’s ATV-4 "Albert Einstein” resupply spacecraft currently docked with the station.
"Thrusters of the European spacecraft will be started at 16:42 Moscow time [12:42 GMT] on Sunday and will remain switched on for 204.22 seconds, giving the station a boost of 0.5 meters per second. As a result, the average altitude of the ISS will be increased by approximately 900 meters (29.5 feet), to 418.8 kilometers (260 miles),” the spokesman said.
Such adjustments are carried out regularly to compensate for the Earth's gravity and to facilitate the successful docking and undocking of spacecraft.
Russian cosmonauts Oleg Kotov and Sergei Ryazansky and NASA astronaut Michael Hopkins will fly to the station aboard a Soyuz TMA-10M spacecraft at 00:58 Moscow time on September 26 (GMT 20:58, September 25).
They will join the current ISS crew, comprising Russian cosmonaut Fyodor Yurchikhin, and astronauts Karen Nyberg of NASA and Luca Parmitano of the European Space Agency.