George, here's the secret advantage: any stuff coming off the Orbiter all
tends to 'cluster' ahead of and below it, as differential drag drops it into
lower faster orbits. Then you look for it, once a rev, at sunset, against
the dark Earth background. MCC runs the camera, the crew isn't even
involved. Meantime, random axis views also scan -- but don't provide 100% --
the space within 100 meters or so of the Orbiter. And regarding +Z
(out-the-belly views), the ET sep camera, in the belly, is being rewired to
allow imagery to reach the crew cabin.