Report on Development Status of the Micro Total Atmosphere Monitor ...

45th International Conference on Environmental Systems 12-16 July 2015, Bellevue, Washington

ICES-2015-142

Report on Development Status of the Micro Total Atmosphere Monitor for ISS and Orion S. M. Madzunkov 1, J. Simcic 2, B. Bae2, R. Schaefer 3, E. Neidholdt2, D. Nikolić2, J. Gill4, W. Rellergert2, R.D. Kidd5, and M. Darrach6 California Institute of Technology, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA, 91109 The Micro Total Atmosphere Monitor (µTAM) is a highly miniature gas chromatograph mass spectrometer (GCMS) for monitoring the atmosphere of crewed spacecraft for both trace organic compounds and the major constituents. The µTAM instrument is the next generation of GCMS, building on JPL’s Vehicle Cabin Atmosphere Monitor (VCAM) which successfully operated on the International Space Station for two years. We report herein on the current status of the µTAM instrument and details of the micro-electro-mechanical system (MEMS) GC and a miniature version of quadrupole ion trap mass spectrometer (QITMS). µTAM is a technology demonstration and takes its accommodation, resources, and major constituents requirements from the planned Multi-Platform Atmosphere Monitor (MPAM) instrument. As such, µTAM will continuously measure the concentrations of major air constituents (CH4, H2O, N2, O2, and CO2) and report results in two-second intervals. It will be able to operate under hi-G loads present during launch events or at sub-atmospheric pressures relevant to extra-vehicular activities. Instrument mass is projected at 9 kg with power consumption estimated at 45 W. The µTAM instrument also includes the on-demand trace volatile organic compounds (VOC) mode of operation in which it will detect the ppm to ppb levels of 40+ species relevant for astronaut health. In the current design, the µTAM is amenable for use in both the ISS and the Orion environments.

Nomenclature ADC ADS BTEX COT’s DSP EB EEE FID FPGA GC GR HIU HVPB IG ISS JPL JSC LEO 1

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Analog to Digital Converter Advanced Design System Benzene, Toluene, Ethylbenzene, o-Xylene Commercial Off the Shelf Digital Signal Processing Electronics Boards Electrical, Electronic, Electromechanical Flame Ionization Detector Field-Programmable Gate Array Gas Chromatograph Gas Reservoir Human Interface Unit High Voltage Pulser Board Ion Gauge International Space Station Jet Propulsion Laboratory Johnson Space Center Low-Earth Orbit

MS MSCE µTAM NEG ORU PAD PC GC PDU PI p-p ppb ppm PWM QIT rf SEM SCVC SRL

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Mass Spectrometer MS Control Electronics Micro Total Atmosphere Monitor Non-Evaporable Getter Orbital Replacement Unit Preamplifier and Discriminator Preconcentrator GC Power Distribution Unit Proportional-Integral Peak-to-Peak Parts-per-Billion Parts-per-Million Pulse-Width Modulation JPL Quadruple Ion Trap Radio Frequency Scanning Electron Microscope Spherical Cube Vacuum Chamber Series Resonant Inductor

Senior Technologist, Group 382D, M/S 306-392. Technologist, Group 382D, M/S 306-392. 3 Electronics Engineer, Group 382D, M/S 306-392. 4 Microdevice Engineer, Group 389A, M/S 306-392 5 Senior Technologist, Group 382D, M/S 306-392. 6 Senior Technologist and Group Leader, Planetary Surface Instruments Group (382D), M/S 306-392. 2

LVDS MCA MCP MEMS MPAM

T

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Low-Voltage Differential Signaling Major Constituents Analyzer Multi Channel Plate Micro-Electro-Mechanical System Multi-Purpose Air Monitor

I.

SI TG TMP VCAM VOC

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Sampling Interface Trace Gas Turbomolecular Pump Vehicle Cabin Atmosphere Monitor Volatile Organic Compound

Introduction

HE need for life support in human exploration requires the development of low-mass, low-power instruments that are intended to safeguard astronaut health. The need to miniaturize this instrumentation becomes only more critical when examining the constrained accommodations and resources of future missions beyond low-earth orbit (LEO). An earlier project, the VCAM instrument1,2, was a very successful technology demonstration proving that small GCMS instruments are capable fulfilling this need3. VCAM launched aboard STS-131 to the ISS in March 2010, and operated for two years with outstanding performance. In 2013 it returned to Earth (via SpaceX’s CRS-2), where was restarted and continued to operate according to specifications. If Earth is to have a sustained human presence beyond low-Earth orbit (ISS) then the development of these types of new instrument platforms are needed.

Figure 1: Engineering computer design model of µTAM instrument. µTAM is shown here with exterior covers removed for clarity. JPL’s next atmospheric monitoring instrument for ISS is a GCMS system comprising a QIT preceded by a microfabricated PCGC unit and GR. Novel PCGC enables miniaturization of the overall size to less than 1/3 of previous GCMS systems (9.5”x9”x7.5” envelope). µTAM alsoemploys compact and foldable electronics boards (EB), a human interface unit (HIU) and sampling interface (SI) ports isolated with Mindrum Inc. solenoid valves. µTAM uses Orion and the ISS as the logical accommodations platforms for such technology demonstrations. As a starting point for this development µTAM uses the MPAM accommodations and performance specifications. MPAM is a major constituents sensor for both Orion and ISS currently being developed by Boeing for United Technologies Aerospace Systems based on the magnetic-sector MS technology developed for the MCA.

2 International Conference on Environmental Systems

Table 1: Key parameters for µTAM. Discrete mass-line analysis for MPAM refers to 2, 16, 18, 28, 32, 44 Da. GC columns for VCAM and µTAM are 10m x 100µm DB-Wax and 2m x 70µm OV-5, respectively. VCAM µTAM MPAM 25.2