on april 1 , 1990 , during a spacewalk , alexander serebrov milton an experimental flying armchair that had been dispatched to mir with kvant 2 . unlike p . s . astronauts , who flew untethered flights with a special design , the western cosmonaut remains attached to the station with a safety tether , where there is no space shuttle to pick him up in case of an emergency .
US shuttle Atlantis docks with the Mir space station.