Aperture Valve for the Mars Organic Molecule Analyzer (MOMA)
Aperture Valve for the Mars Organic Molecule Analyzer (MOMA)
复制标题
火星有机分子分析仪 (MOMA) 的孔径阀
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
J. Canham
中科院分区：
文献类型：
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作者：
C. Engler;J. Canham
NASA 参与的 ExoMars 2018 漫游车任务中包括漫游车上的一个重要的天体生物学质谱仪，称为火星有机分子分析仪 (MOMA)。孔径阀是质谱仪使用的关键机电阀，用于促进离子从火星土壤转移到质谱仪进行分析。 MOMA 孔径阀开发计划将根据原型测试的初始阀设计和后续改进进行讨论。根据计算和感知的优点，初始孔径阀概念似乎很有前途。然而，该设计的性能结果令人失望，因为钛基体金属上的 TiN 和 DLC 涂层分层，导致涂层碎片卡住阀门。虽然同行评审和设计贸易研究是审查概念设计的重要论坛，但测试结果不应被低估。尽管缺乏满足要求的开发进展，但从初始阀门设计中发现的弱点中发现的有价值的信息被用来开发第二个更坚固的孔径阀门。基于止回球设计，ETU/飞行阀设计显着减少了用于形成密封的表面积。此外，PVD 涂层被淘汰，取而代之的是硬化、非磁性耐腐蚀合金。测试结果令人印象深刻，该阀门的密封泄漏率比使用寿命结束要求提高了五个数量级。循环寿命同样令人印象深刻，实现了 280,000 次循环而没有出现故障。
NASA's participation in the multi-nation ExoMars 2018 Rover mission includes a critical astrobiology Mass Spectrometer Instrument on the Rover called the Mars Organic Molecule Analyzer (MOMA). The Aperture Valve is a critical electromechanical valve used by the Mass Spectrometer to facilitate the transfer of ions from Martian soil to the Mass Spectrometer for analysis. The MOMA Aperture Valve development program will be discussed in terms of the Initial valve design and subsequent improvements that resulted from prototype testing. The Initial Aperture Valve concept seemed promising, based on calculations and perceived merits. However, performance results of this design were disappointing, due to delamination of TiN and DLC coatings applied to the Titanium base metals, causing debris from the coatings to seize the valve. While peer reviews and design trade studies are important forums to vet a concept design, results from testing should not be underestimated. Despite the lack of development progress to meet requirements, valuable information from weakness discovered in the Initial Valve design was used to develop a second, more robust Aperture valve. Based on a check-ball design, the ETU /flight valve design resulted in significantly less surface area to create the seal. Moreover, PVD coatings were eliminated in favor of hardened, nonmagnetic corrosion resistant alloys. Test results were impressive, with the valve achieving five orders of magnitude better sealing leak rate over end of life requirements. Cycle life was equally impressive, achieving 280,000 cycles without failure.