United We Orbit It's a story of spacecraft meets spacecraft. -
By James E. Oberg - Air & Space magazine, January 1997 (Page 4
of 5) Before mission STS-71, the astronauts “flew” over 200
approaches in a variety of simulators. Docking with Mir requires
a very slow closing speed—barely more than an inch per second
during the final approach. It also demands great precision. The
docking rings have to be parallel within two degrees in each
axis, and the targets have to be aligned within three inches of
each other. The astronauts have various tools to help them
measure the alignment. A metal “stand-off cross” extends on a
rod above and parallel to a black painted cross on the Mir
target. If the crosses appear in TV views to line up perfectly,
the pilot knows he’s on track. The TV cameras also have grid
markings to make it easier for the astronauts to check their
alignment. One concern had been the disorienting view caused by
the camera’s being at a distance from the pilot’s eyeballs.
“You’re not looking at the real