I bet the computers at DIA would pluck it out in a second or two. The
reason they didn't see the jet was they did not have the algorithm in
there to look for random debris.
===
And it's entirely possible, even likely, that there was no satellite
in the right position at the right time. Satellites are not all that
useful for real time tracking of fast moving targets.
That's the point I am trying to make. "Spy" satellites have optics that
can resolve dimples on a golf ball but you have to know where the golf
ball is to zoom in on it. Land targets are one thing because they don't
move and the GPS coordinates are known. A ship at sea would be very
difficult to find unless you had a good idea where to look and could
limit the search to a highly zoomed area. Oceans are big.