Landmarks must be referenced to Irene’s earth.

FM4/Chief, Mathematical Physics BranchFeb 5 196868-FM-T-24FM/Deputy ChiefLandmarks must be referenced to Irene’s earth.

We were informed at the Sundisk Pre-CARR meeting at MIT on January 25 that the CMC landmark tracking initialization data the crew is to use must be referenced to the Fischer ellipsoid. I'm talking about the numbers listed on their landmark photographs, etc., used during the navigation exercise. I could not remember what we were already using so I thought I would send you this note to make sure you do right.