Why Bandwidth Budgets Favor Sparse Acoustic Features Over Point Clouds

The Mars Exploration Rovers returned about 120 Mb per rover per day during primary mission. A modern LiDAR inside a lava tube produces that in under three seconds. The arithmetic forces a choice: return sparse acoustic features stitched into quilt patches, or give up on returning meaningful survey data per pass. This post walks through the actual Mars relay and DSN numbers, the compression gap for point clouds, and how EchoQuilt's 8 kb/hr quilt patch deltas match the link budget reviewers sign off on.

A flight concept team writing a Mars cave cartography proposal usually runs the relay math early because the answer changes every sensor decision downstream, and a sensor whose output cannot be returned through the actual link is a sensor that does not fly. The DESCANSO MER telecommunications chapter reports MER primary mission returns of about 120 Mb per rover per day. The Mars Relay Network overview describes orbiters returning data at gigabit-class aggregate volumes, but the per-rover, per-pass budget is what matters for cartography.