He was scheduled to make his first space flight in 2020, onboard Soyuz MS-16, but was removed for medical reasons.

In 2013, Tikhonov served as cavenaut into the ESA CAVES[1] training in Sardinia, alongside Soichi Noguchi, Andreas Mogensen, David Saint-Jacques, Andrew Feustel and Michael Fincke.

He was again removed from the manifest due to delays in launching the Russian Nauka module.

He was scheduled to finally make his first flight onboard Soyuz MS-16 in 2020, but ended up replaced for medical reasons.

[4] In July 2020 it was reported he had left the cosmonaut corps "in connection with new data on his state of health".