Revision D of predicted GDC Ephemerides

"RevDEphemsOfficial.zip": a ZIP archive containing eighteen ASCII / CSV data files containing full predicted ephemerides for the prime GDC mission, Reivision D (latest as of September 15, 2025). The file timestamps are in UTC, and each of the six spacecraft (G1 through G6) ephemerides are in a separate file, with further separation by mission phase (Phase1, Phase2, Phase3). The header contains the column data identifiers and units: Time (UTCG) (time in coordinated universal time, in DD Mon YYY HH:MM:SS.MMM format X-J2K(km), Y-J2K (km), Z-J2K (km): J2000 (earth-centered inertial) cartesian coordinates with the satellite position from Earth center, in km Vx-J2K (km/sec), Vy-J2K (km/sec), Vz-J2K (km/sec): J2000 (earth-centered inertial) cartesian velocity components in km/sec LAT (deg), LON (deg): geodetic latitude and longitude of the subsatellite footpoint in degrees ALT (km): altitude above the WGS84 geoid -- note, in these simulations, orbital drag is not accounted for, so othe altitude varies only with latitude, and not with time (at a given latitude)Xsun-J2K, Ysun-J2K, Zsun-J2K: x,y,z components of cartesian unit vector from earth center to Sun, in J2000 coordinates Xpm-J2K, Ypm-J2K, Zpm-J2k: x,y,z components of cartesian unit vector from earth center to the point on the earth's surface where the equator and prime meridian intersect ------- "GDC_RevD_primemission_orbit_visualization.mov.zip": ZIP archive containing a QuickTime movie showing the evolution of the constellation ephemerides for an arbitrary launch day and launch local time.