On February 1, 1990, during a spacewalk, Alexander Serebrov dons an experimental flying armchair that had been delivered to Mir with Kvant 2. Unlike U.S. astronauts, who flew untethered flights with a similar device, the Soviet cosmonaut remains attached to the station with a safety tether, since there is no space shuttle to pick him up in case of an emergency.
They could not risk going out untethered  with no shuttle
( z1 possible :polarity - :ARG1 ( z2 risk :ARG0 ( z3 they ) :ARG1 ( z4 go-out :ARG0 z3 :manner ( z5 tethered :polarity - ) :manner ( z6 shuttle :polarity - ) ) ) )