Estimation of Apollo lunar dust transport using optical extinction measurements

TL;DR

This paper introduces a method to estimate lunar dust transport during Apollo landings by analyzing optical extinction data, linking it to soil erosion and ejected mass, and applying radar-based correlation techniques.

Contribution

It proposes a novel optical extinction analysis method to estimate lunar soil erosion and dust transport, adapting radar rainfall correlation techniques to lunar conditions.

Findings

Optical extinction analysis estimates soil erosion rates.

Radar correlation methods can be adapted for lunar dust.

The approach links particle size distribution to dust transport.

Abstract

A technique to estimate mass erosion rate of surface soil during landing of the Apollo Lunar Module (LM) and total mass ejected due to the rocket plume interaction is proposed and tested. The erosion rate is proportional to the product of the second moment of the lofted particle size distribution N(D), and third moment of the normalized soil size distribution S(D), divided by the integral of S(D)D^2/v(D), where D is particle diameter and v(D) is the vertical component of particle velocity. The second moment of N(D) is estimated by optical extinction analysis of the Apollo cockpit video. Because of the similarity between mass erosion rate of soil as measured by optical extinction and rainfall rate as measured by radar reflectivity, traditional NWS radar/rainfall correlation methodology can be applied to the lunar soil case where various S(D) models are assumed corresponding to specific lunar sites.