180 days (in 1972-1973). The facilities were used for the tests at least until 1984.

In 1986, Dr. Josef Gitelson, head of the Institute of Biophysics (IBP) at Krasnoyarsk and developer of biospherics as well the BIOS project, met with Oleg Gazenko, Mark Nelson, John Allen and others involved with Biosphere 2, which led to further cooperation. In 1989, a group from Biosphere 2 visited the BIOS-3 facilities. Mark Nelson and