Lunar Soil Water Ice Measurement with Sublimation Loss Correction
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Solution Overview
Problem
Existing methods for inverting the true mass content of water ice in lunar soil suffer from significant errors due to sublimation loss, vapor adsorption, and system leakage during drilling, heating, and extraction processes, leading to inaccurate measurements.
Innovation Solution
A method using a lunar soil water molecule analyzer (LSWMA) that accounts for sublimation loss, vapor adsorption, and system leakage by calculating sublimation rates, correcting pressure measurements, and compensating for extraction efficiency to determine the true mass content of water ice in lunar soil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If drilling, heating, and extracting lunar soil to convert water ice into water vapor for measurement, then water ice extraction efficiency is improved, but sublimation loss during transfer causes measurement error
Solution Approach 1:
The patent applies preliminary action by pre-calculating and pre-compensating for sublimation loss based on temperature data and transfer duration before final measurement. The system predicts the sublimation loss that will occur during transfer and adjusts the measurement accordingly, allowing accurate quantification despite the inevitable sublimation loss during the extraction and transfer process.
2Quantity of substance
If heating lunar soil to high temperature to convert water ice into water vapor, then water ice extraction efficiency is improved, but water vapor adsorption in pipelines causes measurement error
Solution Approach 1:
The patent applies feedback by continuously monitoring pressure changes in the measurement chamber and using this information to calculate water vapor concentration. The system adjusts for adsorption losses by comparing expected pressure changes with actual measurements, allowing accurate quantification of water ice content despite water vapor adsorption in the pipeline system.
3Difficulty of detecting and measuring
If using interconnected pipeline-spectral unit system for water vapor measurement, then measurement capability is improved, but system leakage compounds vapor loss causing inversion error
Solution Approach 1:
The patent applies feedback by monitoring pressure changes over time in the measurement chamber and using this information to distinguish between genuine water vapor signal and leakage artifacts. The system calculates water vapor concentration based on the rate of pressure change, allowing accurate measurement even in the presence of system leakage through the interconnected pipeline-spectral unit system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method provides accurate water ice content measurements with a sensitivity of 0.1 wt% or better, supporting reliable evaluation of lunar water resources.
Implementation Method 1
A heating capability of a Metal Ceramic Heater (MCH) of the sample receiving cup is used to heat the lunar soil to convert the water ice in the lunar soil into the water vapor
Implementation Method 2
All the water vapor enters a spectral unit of the LSWMA through a pipeline, and water molecule molar concentration is measured by the spectral unit
Data Source
AI summary
A method for inverting true mass content of water ice in lunar soil using a lunar soil water molecule analyzer (LSWMA) includes: obtaining weight data of a lunar soil sample, temperature data of a sample receiving container that receives the lunar soil sample, and duration of a transfer process of the lunar soil sample; obtaining measurement data of total pressure of the water vapor; calculating a sublimation loss based on a sublimation rate and the duration of the transfer process, and estimating a relative sublimation loss rate; correcting the measurement data of the total pressure of the water and obtaining true pressure data of the water vapor; and calculating, based on the true pressure data of the water vapor, mass of the water vapor, and further calculating mass content of water ice in lunar soil.