KOROLEV (Moscow Region), October 30. /TASS/. Russian spacecraft of the new Soyuz MS family is to return to the Earth from the International Space Station (ISS) at around 7am Moscow Standard Time (04am UTC) on Sunday, bringing back from a 115-day long space mission Russian cosmonaut Anatoly Ivanishin, NASA astronaut Kathleen Rubins and Japanese astronaut Takuya Onishi.

"In the run-up to the undocking, the crew has moved to the Soyuz MS spacecraft and sealed off the transfer hatches," a source at the Mission Control Center near Moscow told TASS.

Staying back at the station are the Russian cosmonauts Andrei Borisenko and Sergey Ryzhykov and NASA astronaut Robert Shane Kimbrough.

The undocking of the Soyuz MS from the ISS Rassvet mini-research module has been scheduled for 3:35am Moscow time. Prior to it the crew is verifying the sealing of the craft, putting on the descent suits, and testing the proper functioning of all the systems.

At 6:06am, the spacecraft engines will be switched into the de-boosting mode, and the descent from orbit will begin. The onboard equipment section and the habitation module will separate from it at 6:33am and the descent capsule with the three cosmonauts will enter the atmosphere at 6:36am.

The crew will experience the maximum 4g overpressure effect at the altitude of 33 km above the surface of the Earth ten minutes after entering the atmosphere. This means they will experience pressure of a weight exceeding their own by a factor of four.

A command for parachute deployment will be given at 6:44am and the touchdown is due to take lace at 6:59am in the Kazakhstani steppeland some 148 km to the southeast of the city of Jezkazgan.

The first ship in the Soyuz MS family lifted off towards the ISS on July 7, 2016. It docked to the ISS two days later.

The second ship was launched on October 19 and is docked to the ISS at present.