MOXIE Mars Oxygen ISRU Experiment - CERTIFIED
                                       July X, 2021 (Ls X MY X) to [ongoing]


    Moxie pic
    Technicians in the clean room are lowering the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) instrument into the belly of the Perseverance rover. Credit NASA/JPL-Caltech


    Experiment Overview


    MOXIE is a technology demonstration of In-Situ Resource Utilization (ISRU) technologies to enable propellant and consumable oxygen production from the Martian atmosphere. This demonstration is a precursor to developing the technology to produce the large mass of cryo- genic propellants needed to power an ascent vehicle to transport astronauts from the Mars surface to the orbiting return vehicle.

    Goals
    1. Verify and validate the technology of Mars ISRU as a springboard for the future
    2. Establish achievable performance requirements and design approaches that will lead to a full-scale ISRU system based on MOXIE technology.


    Requirements
    1. To be capable of producing at least 6 g/hr of oxygen in the context of the Mars 2020 mission (assuming atmospheric intake at 5 Torr, typical of Jezero Crater, and 0°C, typical of the rover interior).
    2. To produce oxygen with > 98% purity.
    3. To meet these first two requirements for at least 10 operational cycles after delivery. Since MOXIE is expected to operate in all seasons and at all times of day and night on Mars, these requirements are intended to be satisfied under worst-case environmental conditions, including during a dust storm, if possible.


    The future ISRU technology would need to be scaled up about 200 times to autonomously provide at least 24 metric tons (MT) of liquid oxygen (LOX) for ascent vehicle propellant in the 16 months preceding the launch of a human crew to Mars.

    MOXIE is installed in the belly of a Perseverance, relatively insensitive to external temperatures except for the temperature of the gas intake. An operations cycle will span one martian SOL. And will use a full SOL payload allocation of ∼ 1000 W-hrs. Operation cycles will allow assessment of the robustness of MOXIE’s technical performance (flow rate, oxygen production rate, oxygen purity, voltage–current relationship of SOXE), and provide the opportunity for the team to learn how to optimize performance, and to understand how performance changes with environmental conditions and repeated use. Initial plans are to operate MOXIE 10 times over the course of one Mars to access how well it works in varying seasons.


































    This functional block diagram illustrates the MOXIE process. MOXIE collects CO2 from the Martian atmosphere, then electrochemically splits the CO2 molecules into O2 and CO. The O2 is then analyzed for purity before being vented back out to the Mars atmosphere along with the CO and other exhaust products.

    The CO2 Acquisition and Compression (CAC) system pulls Martian atmosphere from outside the Rover through a filter and pressurizes it to ~1 atmosphere. The pressurized CO2 gas is then regulated and fed to the Solid Oxide Electrolyzer (SOXE), where it is electrochemically split at the cathode to produce pure O2 at the anode, a process equivalent to running a fuel cell in reverse.

    The SOXE operates at 800° C, requiring a sophisticated thermal isolation system, including input gas preheating and exhaust gas cooling. There are O2 exhaust and CO2/CO exhaust streams, which are then analyzed to verify O2 production rate and purity and for process control. The electrical current through the SOXE is a direct result of the oxide ions transported across the electrolyte. The current provides an independent measurement of O2 production rate.

    Based on conversion efficiency calculated from flow rates and composition measurements, SOXE control parameters such as CO2 input flow rate, temperature, and applied voltage are used to optimize O2 production under Mars environmental conditions. The cooled exhausts are then filtered to satisfy planetary protection requirements and vented from the Rover. Process telemetry is reported to the Rover for downlink.

    Background Publications


    Farley, K.A., Williford, K.H., Stack, K.M. et al. Mars 2020 Mission Overview. Space Sci Rev 216, 142 (2020). https://doi.org/10.1007/s11214-020-00762-y

    Balaram, J., Aung, M. & Golombek, M.P. The Ingenuity Helicopter on the Perseverance Rover. Space Sci Rev 217, 56 (2021). https://doi.org/10.1007/s11214-021-00815-w

    MOXIE Documents
    Summary Article - Hecht, M., Hoffman, J., Rapp, D. et al. Mars Oxygen ISRU Experiment (MOXIE). Space Sci Rev 217, 9 (2021). https://doi.org/10.1007/s11214-020-00782-8

    Software Interface Specification document (SIS)


    Archive Products

    Data from other instruments and rover
    During a MOXIE run, data from three other instruments are recorded: the Mars Environmental Dynamics Analyzer (MEDA), SuperCam, and Entry, Descent and Landing camera (EDLcam). In addition, several rover parameters are relevant to MOXIE operation, for example, Rover Avionics Mounting Panel (RAMP) temperature. MEDA records atmospheric pressure, surface temperature, relative humidity, upward and downward radiative fluxes in several solar and infrared bands, and atmospheric temperature, wind speed, and 3D wind direction at ~1.5 m, at 1 Hz. During MOXIE runs, MEDA will record a subset of the above (atmospheric pressure, temperature, optical depth, wind speed, and 3D wind direction at ~1.5 m, at 1 Hz) from 3 minutes before the start of oxygen production until 3 minutes after the end of oxygen production. In addition, MEDA’s Radiation and Dust Sensor-Skycam (RDS)-Skycam is also scheduled to acquire two images of the sky each sol to retrieve optical depth, a measure of atmospheric column dust content.The SuperCam and EDLcam microphones are intended to record audio from one minute before to five minutes after the start of scroll compressor operation; from one minute before to two minutes after any change in scroll compressor RPM commanded via the RCT; and from one minute before to one minute after the end of scroll compressor operation.

    Data product description


    Each MOXIE run is stored in a separate directory identified by martian day (sol), beginning on sol 60 (April 20,2021). A run lasts around 3.5 hours: 2.5 hours of warmup followed by 1 hour of oxygen production. See SIS Quick Start Guide for accessing dataa. Link to SIS File .

    Each data file (raw, calibrated and derived) is stored as a CSV file and contains time series of parameters sampled at 1 Hz (See indices for summary).

    Don’t do anything with the green text. It’s info I pulled from the sis anticipating using the XML label to set up the items we incorporate in the Indices. Although they mention derived data there is no description in the SIS do I assume we aren’t getting any.

    Raw
    The raw data product consists of two files: one data file in CSV format (Section 4.1), and one PDS4 label file in XML format (Section 4.2). The raw data product generation process is shown in Figure 4-1: Figure 4-1: Raw data product generation process If the MOXIE run is nominal (no faults declared), a MoxiScidataFrame data product is produced on board the rover. If the MOXIE run is off-nominal (one or more faults declared), a MoxieFault data product is produced on board the rover. The MoxiScidataFrame and MoxieFault data products are used to produce science and fault raw data products respectively.

    Calibrated
    The calibrated data product consists of two files: one data file in CSV format and one PDS4 label file in XML format. Field names, descriptions and units for the calibrated data product are listed in Table 5-1. Refer to Table 5-2 for the equations used to convert the raw data product values in DN into the calibrated data product values in CU.

    Selected data can be retrieved in 2 ways

    1) Downloading an index, selecting components and uploading your selection.

    Indices that tabulate information associated with each product are available.

    a. Select your index

    b. Sort and make your selection

    c. Upload the URN values from your revised index (note the total uncompressed file size before requesting)


    2) Selecting specific parameters and requesting limited data files


    Downloading annual collections of data

    Citing datasets for publication

    Bibliography - A listing of team members to facilitate literature searches

    Spice - Archived SPICE ancillary data providing observation geometry (positions, orientations, instrument pointing, time conversions, etc.) are available from the PDS NAIF Node.