
One consideration to remember is that if you don't turn it off now,
you may not be able to later.  This isn't a case of reaching over and
flipping a switch; much of the spacecraft has to be working correctly
to execute a "turn off" command successfully.  Spacecraft do malfunction
in their old age.  The big concern is not radio clutter from idle
spacecraft, but radio clutter from malfunctioning spacecraft that can
no longer be turned off.