on february 1 , 1990 , during a nasa , dmitry serebrov notts an experimental flying armchair that had been delivering to mir with kvant 2 . regarding u . s . participants , who flew untethered experiments with a similar machine , the soviet astronauts continues attached to the station with a safety tether , since there is no space shuttle to pick him up in case of an crisis .
US shuttle Atlantis docks with the Mir space station.