We're about 13.5 hr from landing. I'm sitting in the "play call" meeting to
decide if we need to do a last-minute rush-rush Trajectory Correction (aka
TCM-6). This is a pre-planned meeting in case we had some kind of bad Navigation
surprise at the last minute, but the trajectory estimates look very very good.
The estimated errors are coming down as expected and we are only a few hundred
meters (in the targeting "B-plane") from the trajectory state we put on the
spacecraft a few days ago. We are sure at this point that we don't need to do
TCM-6, but we might still make an update to the onboard trajectory knowledge.
Attitude control has been looking fine. I just compared the spin axis from the
onboard sensors to one estimated by the NAV team from the doppler and they agree
to within about 0.02 deg. It's important we get this right because along with
the trajectory uplinked from the ground, we use the onboard attitude estimate to
initialize the IMU which controls our guided entry.
Getting close now. Cross your fingers.