The Spacecraft Atmosphere Monitor (S.A.M.) is a miniaturized gas chromatograph mass spectrometer (GC/MS) instrument for monitoring the cabin atmosphere for human spaceflight missions. The first Technology Demonstration Unit (TDU1) operated successfully aboard the International Space Station (ISS) from August 2019 to July 2021. The second unit, TDU2, will be delivered to ISS in 2023. While on-station, TDU2 will continuously monitor the major atmospheric constituents and, on command, perform analysis of the cabin atmosphere for trace organic volatiles. The S.A.M. TDU2 uses the same quadrupole ion trap mass spectrometer (QITMS) sensor as in TDU1, but includes a MEMS preconcentrator, gas chromatograph, and microvalve system. Its miniature, ruggedized form factor allows the S.A.M. to be aisle-deployed to monitor the cabin in different locations and during activities such as exercise and sleep.

Jet Propulsion Laboratory (JPL) is developing a Quadrupole Ion Trap Mass Spectrometer (QIT-MS) suited for detecting ppm and ppb levels of organics within the liquid sample. The QIT-MS sensor is of the same heritage as one used in Spacecraft Atmosphere Monitor (S.A.M.). However, the pumping system, introduction of the sample, and operational architecture and procedures are different. We present our progress in this new instrument development and illustrate its ruggedized design by injecting 98% concentrated sulfuric acid that has the potential as a solvent for biochemistry. Using ruggedized QIT-MS to detect organic species dissolvable in water is straightforward and directly supports Spacecraft Water Impurity Monitor (SWIM) technology development.

Astronauts are exposed to a unique radiation environment during space missions. This environment is dominated by high charge and energy (HZE) ions with sources that include solar energetic particles (SEPs), galactic cosmic rays (GCRs), and trapped electrons and protons around planetary bodies with substantial magnetic fields. Traditional shielding strategies aim to reduce astronaut radiation exposure by increasing vehicle mass, but this is ineffective for the extremely penetrating GCRs. Use of electromagnetic fields has been investigated previously, but these studies have been limited to single point designs. The NASA Active Shielding project has instead developed a workflow that includes a fast and accurate particle propagation code (Active Shielding Particle Pusher), which can be used to rapidly evaluate the shielding efficacy of many different permutations of electromagnetic shielding designs. While some validation of the code has been previously done, additional validation is needed to increase user confidence in simulation results involving more complicated electrostatic conductor configurations. In the present study, we evaluated shielding properties of spherical electrode arrays and planar grid structures against 2 MeV or 6 MeV H+ and 22.5 MeV Fe6+ ions using ASPP, SIMION, and COMSOL, and compared these results to laboratory-based measurements. Many numerical experiments were conducted to reproduce experimental ion beam tests that measure the consequential particle reduction rate in a safe zone compared to the initial number of ions. The experimental visualizations were also compared with the present numerical results and found to be in close agreement with each other for all considered voltage combinations applied to electrode structures. This comparison allows us to use numerical models to predict the behavior of complex shielding structures at much larger scales not feasible in a laboratory environment.

The Spacecraft Atmosphere Monitor (SAM.) is a scientific payload, which includes a Paul quadrupole ion trap (QIT) mass spectrometer and has been continuously operated onboard the International Space Station (ISS) between August 2019 and July 2021. S.A.M. measures the chemical composition of ISS cabin air and reports on major constituents (N-2, O-2, Ar, CO2, and CH4) once every 2 s. Each second, S.A.M. measures one hundred individual mass spectra stored in 4800 ins-long channels. This report presents the autonomous onboard data analysis software that calibrates the mass spectrum, removes the residual gas background signal, identifies species of interest, and reports relevant abundances. In addition, we describe a ground-based analysis of downloaded S.A.M.'s data to extract the H, C, N, O, and Ar isotope ratios. We also describe experiments, requested by the ISS Vehicle office, to ascertain if benzene was present in the ISS cabin air (it was not). We demonstrate that S.A.M. instrument measures isotope ratios with precision and accuracy comparable to the state-of-the-art laboratory-size magnetic sector mass spectrometers. (C) 2022 Elsevier B.V. All rights reserved.

To date a variety of different types of Mass Spectrometers has been utilized on missions to study the composition of atmospheres of many solar system bodies including Venus, Mars, Jupiter, Titan, the moon and several comets. For in-situ exploration of ice giant atmospheres, the highest priority composition measurements are helium and the other noble gases, noble gas isotopes, and other key isotopes including 3He/4He and D/H. Other important but lower priority composition measurements include abundances of volatiles C, N, S, and P, isotopes 13C/12C, 15N/14N, 18O/17O/16O and disequilibrium species PH3, CO, AsH3, GeH4, and SiH4. Required measurement accuracies are largely defined by the accuracies achieved by the Galileo (Jupiter) probe Neutral Mass Spectrometer and Helium Abundance Detectors, and current measurement accuracies of solar abundances[1]. The Jet Propulsion Laboratory’s Quadrupole Ion Trap Mass Spectrometer (QITMS)[2] is a compact, wireless instrument with a mass of only 7.5 kg, designed to meet these requirements and challenges specific to the planetary probe missions. It is currently the smallest flight MS available, capable of making measurements of all required constituents in the mass range 1-600Da, with a sensitivity of up to 1013 counts/mbar/sec and resolution of m/∆m=12000 at 40Da. During a fly-by or a descent mission, the time available to perform an in-situ measurement is usually short. This makes it challenging to measure the abundances of minor constituents for which long integration times are needed. Mass spectrometers largely employ a non-discriminatory electron impact ionization of sampled gas mixtures for creating ions, which means the probability to create and trap ion fragments of trace species is very low and further destabilized by space charge effects due to an excessive number of ions from dominant species. A selective resonant ejection technique was employed to lower the amount of major constituent species, while keeping the minor constituents intact, which resulted in higher accuracy measurements of minor species. Another inherent challenge of planetary entry probe mass spectrometers is the introduction of material to be sampled into the instrument interior, which operates at vacuum. Atmospheric entry probe mass spectrometers typically require a specially designed sample inlet system, which ideally provides highly choked, nearly constant mass-flow intake over a large range of ambient pressures. An ice giant descent probe would have to operate over a range of atmospheric pressures covering 2 or more orders of magnitude, 100 mb to 10+ bars, in an atmospheric layer of ~120 km at Neptune to ~150 km at Uranus. The QITMS features a novel MEMS based inlet system driven by a piezo-electric actuator that continuously regulates gas flow at inlet pressures of up to 100 bar. In this paper, we present an overview of the QITMS capabilities including instrument design and characteristics of the inlet system, as well as the most recent results from laboratory measurements in different modes of operation. [1] Mousis, O., et al., Pl. Sp. Sci., 155 12–40, 2018. [2] Madzunkov, S.M., Nikolic, D., J. Am. Soc. Mass Spectrom. 25(11), 2014.

Space radiation in the form of Solar Energetic Protons (SEPs) and Galactic Cosmic Rays (GCR) poses a substantial risk for long-duration space exploration. Active shielding concepts, i.e. shielding a spacecraft with electric and or magnetic fields, has been a topic of interest for more than 50 years. Mass and power requirements have yet to be fulfilled to enable active shielding technology. We present results for a single electric dipole to show the utility of scale-invariance and universal scaling for advancing active shielding concepts. Scattering patterns downstream from the dipole of 2 MeV to 6 MeV electrons and protons show a semi-circular region devoid of incident particles that increases in size with increasing dipole voltage. In particular, results are presented that show how scale-invariant approaches can be leveraged to enable small-scale shields to be built and tested on the ground and then scaled up for in-space use.

The first Micro-Electro-Mechanical System (MEMS) Preconcentrator (PC) and Gas Chromatograph (GC) have been developed for NASA's Spacecraft Atmosphere Monitor (S.A.M.), with the second technology development unit (TDU2) under development for the International Space Station (ISS). The S.A.M. TDU2 is a miniaturized Gas Chromatograph/Mass Spectrometer (GC/MS) instrument, which will be sent to the ISS in 2021. The S.A.M. PC has a gain of more than 3000, enabling sub-ppm sensitivity of the instrument. The S.A.M. GC microcolumn is capable of separating more than 20 targeted compounds in the air of the ISS cabin. The MEMS PC/GC chips are packaged, successfully sealed, and to be integrated with the JPL developed Quadrupole-Ion Trap MS, which enables high vacuum operation during trace gas analysis. The MEMS PC/GC and its integration with the MS contribute to S.A.M. operating under 50% of the Vehicle Cabin Atmosphere Monitor (VCAM) [1] power consumption with a compact footprint, 33% of VCAM's mass and volume.

The Enceladus plume is a target of astrobiological interest in planetary science since it may carry signs of extraterrestrial life entrapped in ice grains formed from the subsurface ocean of this moon of Saturn. Fly-by mission concepts have been proposed to perform close investigations of the plume, including detailed in situ measurements of chemical composition with a new generation of mass spectrometer instrumentation. Such a scenario involves high-velocity collisions (typically around 5 km/s or higher) of the instrument with the encountered ice grains. Postimpact processes may include molecular fragmentation, impact ionization, and various subsequent chemical reactions that could alter the original material prior to analysis. In order to simulate Enceladus plume fly through conditions, we are developing an ice grain accelerator and have coupled it to the quadrupole ion trap mass spectrometer (QITMS) developed for flight applications. Our experimental setup enables the creation and acceleration of ice particles with well-defined size, charge, and velocity, which are subsequently directed into the QITMS, where they impact the surface of the mass analyzer and the analysis of postimpact, volatilized molecules takes place. In this work, we performed mass spectral analysis of ice grains of ca. 1.3 μm in diameter, accelerated and impacted at velocities up to 1000 m/s, with an upgrade of the accelerator in progress that will enable velocities up to 5000 m/s. We report the first observations of ice grain impacts measured by the QITMS, which were recorded as brief increases in the abundance of water molecules detected within the instrument.

The JPL Mass Spectrometer Team develops components and instruments based on a Paul quadrupole ion trap mass spectrometer (QIT-MS) for Earth and space applications. Over the past 20 years, the team has miniaturized the QIT-MS and verified its performance successfully for the International Space Station. The technology was demonstrated with the recent delivery of the first Spacecraft Atmosphere Monitor (S.A.M.) to the International Space Station (ISS). The next step is to build a QIT-MS intendent to investigate the lunar exosphere via a funded ROSES 2019, DALI/NASA proposal over the next three years. The QIT-MS will be the first in-situ lunar mass spectrometer capable of identifying and quantifying exosphere species (ex. H, H2, 3He, 4He, Ne, N2, O2, Ar, CH4, CO, CO2, Kr, Xe, OH, H2O) with abundance greater than 10 molecules/cm3 [1]. The combination of low mass (7.5 kg), low power (max. 30W with heater bulb on), high sensitivity (0.003 counts/cm3/sec), and ultrahigh precision (1.7 x 10-10 Torr, Kr measured continuously for 7 hours yielded a 0.6 ‰ precision on the 86Kr/84Kr ratio) will provide an unpreceded inside of the scientific processes in the lunar exosphere. Other implementation approaches will be discussed, which entail the development of different frontends to expand applications for dense atmospheres (ex. Venus) or liquids (ex. ocean worlds). Most of these developments can be used to determine contaminants in the air, water, or volatile in solids. [1] G. Avice, A. Belousov, K. A. Farley, S. M. Madzunkov, J. Simcic, D. Nikolic, M. R. Darrach and C. Sotin, “High-precision measurements of krypton and xenon isotopes with a new static-mode quadrupole ion trap mass spectrometer,” JAAS, Vol 34, January 2019 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109

A quadrupole ion trap mass spectrometer measures precisely the abundance and isotopic composition of small amounts of noble gases.

Introduction: Noble gases are powerful tracers of physical processes such as the delivery of volatile elements to planetary atmospheres through meteoritic/cometary bombardment [1,2], atmospheric escape, degassing from the silicate parts of planets, etc. In this context, understanding the isotopic composition of Xe in planetary atmospheres is a high priority since Xe isotope ratios can answer fundamental questions such as i) What is the delivery mix (Chondritic/Solar/Cometary) to planetary atmospheres?; ii) To what extent is the silicate portion of a planet degassed?; iii) How much of the atmosphere was lost through atmospheric escape and what is the timing of this process? While recent results from space missions contributed substantially to our knowledge of the elemental and isotopic composition of noble gases on Mars [e.g. 3] and in comets [e.g. 4], some planetary reservoirs remain to be sampled and analyzed. For example, the composition of the atmosphere of Venus is still a missing piece of the noble gas puzzle [5]. Compact mission concepts to sample the Venus atmosphere below the homopause and to measure noble gases with the JPL Quadrupole Ion Trap Mass Spectrometer (JPL-QITMS) have recently been proposed [6]. QITMS or Paul traps were invented 6 decades ago [7], but their potential use as a mass spectrometer for noble gases was explored only recently. For example, in the 1990's, a team at JPL developed a QITMS and demonstrated its ability to measure the abudances and isotopic composition of noble gases [eg. 8]. Another study demonstrated the ability of the JPL-QITMS to measure at high precision the composition of various artificial isotopic mixtures of Xe in dynamic mode [9]. In many mission scenarii, a dynamic measurement is not envisageable. For example, a mission to the Venus atmosphere would collect a sample below the homopause (where gas atoms are well mixed) with ppm to ppb levels of noble gases and measure it only afterwards. Ability to measure gas in static mode would thus be required. Here we show that recent developments of the instrument allow measurement of Kr and Xe isotopes in static mode with a sensitivity and precision meeting the analytical requirements for characterization of the Venus atmosphere. Instrumentation and calibration: Description of the QITMS. The JPL-QITMS consists of three electrodes. In the current configuration, the top and bottom (end-cap) electrodes are grounded whereas the ring electrode receives a high-voltage radiofrequency signal (1-2 kV). Gas neutrals are ionized by electron-impact in the mm-sized space between electrodes via a side-mounted electron gun composed of a Ta cathode and an Einzel lens. A voltage ramp applied to the ring electrode ejects ions along the zaxis (Fig. 1). Ions are detected with a MAGNUM Channeltron electron multiplier operated in pulsecounting mode. The whole system is placed in a vacuum chamber permanently pumped via a turbomolecular pump (pressure lower than 10 torr) except when a sample of gas is to be analyzed. During "static mode" analysis the chamber is isolated from the turbopump and a SAES NP10 getter in the chamber removes residual gases and reduces the partial pressure of hydrogen.

In this paper, we report a MEMS preconcentrator (PC) -gas chromatograph (GC) that is a crucial part of the Spacecraft Atmosphere Monitor (S.A.M.).The S.A.M. is a highly miniature gas chromatograph -mass spectrometer (GC-MS) for monitoring the atmosphere of crewed spacecraft for both trace organic compounds and the major constituents of the cabin air.The S.A.M. instrument is the next generation of GC-MS, based on JPL's Vehicle Cabin Air Monitor (VCAM), which was launched to the International Space Station (ISS) in April 2010 and successfully operated for two years [1,2].The S.A.M. employs a unique MEMS PC-GC technology that replaces the macro PC-GC unit in the VCAM.We report herein the current progress of the MEMS PC-GC for the S.A.M. instrument.

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.

Presented herein is the progress on developing a new mass analyzer for analysis of the exospheres of planets, moons, and primitive bodies, such as found at Europa or Enceladus. Europa, one of Jupiter's four Galilean moons, may have a subsurface ocean plausibly containing the key ingredients for life as well as sources of chemical energy. Clues to the composition and chemical state of Europa's ocean can be found both on Europa's icy surface and in its tenuous atmosphere. Given the high scientific priority of assessing the habitability of Europa's ocean, the Europa Clipper notional payload includes a Neutral Mass Spectrometer whose purpose is to characterize the composition of ejected surface products during a series of flyby investigations.The Mass Analyzer for Real-time Investigation of Neutrals at Europa (MARINE) is capable of measuring the abundances of neutral particle species in Europa's exosphere including H2O, O-2, CO2, and SO2, and determining their number density profiles at per-second sampling rates as a function of altitude above Europa's surface. MARINE will either detect tracers of potential subsurface biological activity in Europa's exosphere, or place upper limits on their surface abundances. It exceeds all requirements for the proposed investigations with margins ranging from 100 to 1000%, while remaining fully compatible with spacecraft accommodation constraints for mass, power, data volume, and field-of-view.