Design of the ground data processing and operations segment for the ET (Earth 2.0) mission

The ET mission will deliver unprecedented time-domain data sets for exoplanets and stellar astrophysics: six 28-cm transit telescopes downlink full-frame images at 15-minute cadence and postage stamps for selected targets, while a 35-cm microlensing telescope returns 10-minute cadence imaging toward the Galactic bulge. With a total data rate of 2500Gb per day and survey scales of >5 million FGKM dwarfs and >30 million bulge stars, the Ground Data Operation Segment (GDOS) is a critical element that transforms raw telemetry into validated science products and provides reliable, timely access for the community. This paper presents: (1) a science-driven requirements analysis; (2) the end-to-end ground processing flows for both the transit telescope array and the microlensing payload; and (3) the design framework for the science database and user service platform.