Scientific International Research in Unique Terrestrial Station (SIRIUS) is a series of experiments that investigate the effects of isolation and simulates a flight to the Moon at the Institute of Biomedical Problems (IBMP) in Moscow, Russia.
The 6 person crew conducted over 60 experiments, "captured" satellites using a manipulator arm and controlled a rover on the Moon's surface.
One experiment consisted of 38-hours of sleep deprivation, during which crew members had to perform a manual VR-simulated docking of the planned Orel spacecraft with a booster rocket in Earth's orbit.
After the return and docking of the lander with the simulated Gateway, the whole crew will orbit the Moon for 30 days, remotely control rovers on the lunar surface, dock spaceships with the Orbital Platform, and carry out other experiments before their "return to Moscow".
In 2021 six participants (Oleg Blinov, Victoria Kirichenko and Ekaterina Krayakina from Russia, William Brown and Ashley Kowalski from the US and Abdalla AlHammadi from the UAE) conducted an eight month stay.