In the pursuit of accurate lunar soil volatile exploration, in-situ deep space sampling analysis offers unparalleled preservation of sample integrity. A critical challenge lies in ensuring a secure sealing environment. This paper introduces an innovative sealing method utilising a ceramic blade to compress a non-metallic seal. Initially, following a comprehensive multidimensional evaluation of sealing configurations, the ceramic knife-edge compression non-metallic sealing ring solution was determined to be optimal. This approach involves positioning the sealing ring within a grooved cylindrical heating furnace body, where radial compression is achieved through an annular ceramic knife-edge interface, thereby ensuring hermetic integrity. Subsequently, a sealing leakage model grounded in Roth theory was developed to elucidate micro-leakage mechanisms. ANSYS simulation software was utilised to investigate the influence of blade tip radius and temperature, revealing correlations with average stress and contact width, as well as the impact of temperature extremes on sealing efficacy. These findings provided the theoretical underpinning for subsequent ground tests. A dedicated test platform was established, adhering to the industry standard QJ3089A-2018, to evaluate the sealing performance of various seal and blade tip radius combinations under diverse conditions. Results indicated that, under a force of 500 N, PTFE seals compressed by an R0.5 mm blade and PVMQ seals compressed by an R0.6 mm blade achieved leakage rates on the order of 10-8 Pa m3 s-1, aligning with theoretical predictions and demonstrating repeatable sealing capability. This study presents a novel and reliable sealing solution for the precise exploration of lunar soil volatiles, offering a technical breakthrough and robust sealing strategy for future deep space missions. (c) 2025 COSPAR. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

The nitrogen isotopic compositions of lunar soil have important implications for the sources of lunar volatiles and even the evolution of the moon. At present, the research on the lunar nitrogen isotopic compositions is mainly based on the lunar meteorites and the samples brought back by the Apollo and Luna missions. However, volatiles adsorbed on the surface of the lunar soil may be lost due to changes in temperature and pressure, as well as vibration and shock effects when the sample is returned. At the same time, in the case of low N content in the sample, since N is the main component of the earth's atmosphere, it is easily affected by the atmosphere during the analysis process. Therefore, in situ nitrogen isotopic analysis of lunar soil on orbit is necessary to avoid the problems mentioned above and is one of the primary science goals for the Lunar Soil Volatile Measuring instrument on Chang'e-7 spacecraft. After the nitrogen purification procedure, the volatiles in lunar soil that are released through single-step or stepped heating techniques diffuse to the quadrupole mass spectrometer to obtain the N contents and isotopic compositions of the lunar soil. This paper introduces the ground test for N isotopic analysis of lunar soil in orbit according to the Lunar Soil Volatile Measuring Instrument. After long-term repeated measurements, the background and CO-corrected Air-STD 14N/15N ratio is 268.986 +/- 4.310 (1SD, n = 35), and the overall reproducibility of measurements is 1.6%. The accuracy of N isotopic compositions is calculated to be better than 5%, which can distinguish different sources of N components in lunar soil.