on february 1 , 1990 , during a spacewalk , alexander serebrov dons an experimental floating chair that had been delivery to moscow with kvant 2 . unlike u . s . scientists , both flew untethered journeys with a similar device , the other cosmonaut remains linked to the station with a control tether , as there is no space shuttle to bring him up in case of an emergency .
US shuttle Atlantis docks with the Mir space station.