2/27/2017 CIM | TPMS |

https://www.cim.org/en/TPMS­Event/Chair/ChairAbstractPool.aspx 1/1

Abstract #1666

English

The latest from MOXIE

Essential subsystems of the Mars Oxygen ISRU Experiment (MOXIE) on NASA’s Mars 2020 mission have passed their Critical Design Review, and the project isbeginning a flight build stage that will culminate in delivery of flight hardware in late 2018. Also being delivered to the MOXIE Science Team is an Engineering Model,equivalent in form, fit, and function to the flight hardware, that will support Mars 2020 mission operations and subsequent extensions of the MOXIE flightdemonstration (for example, tests of long duration operation). As a scale model of a future oxygen production facility on Mars, MOXIE will generate a minimum of 6g/hr high purity oxygen from the Martian atmosphere in at least 15 separate runs, sampling different environmental conditions on Mars, in the 2.5 years followinglanding of the Mars 2020 rover in February, 2021. The presentation will review the MOXIE scroll pump for CO2 collection and compression, the solid oxideelectrolysis system and its packaging for CO2 conversion to O2, the monitoring and control subsystem, and the expectations for operation on Mars.

French

No abstract title in French

No French resume

Author(s) and Co­Author(s)

Dr. Michael H Hecht(UnknownTitle)MIT Haystack Observatory

N/A The MOXIE Team(UnknownTitle)MIT Haystack Observatory

4/26/2017 CIM | TPMS |

https://www.cim.org/en/TPMS­Event/Chair/ChairAbstractPool.aspx 1/2

Profile of Dr. Michael Hecht

General

Email(s): mhecht@haystack.mit.edu Position:

Preferred Language: [Language not defined]

Addresses

Biographies

Collaborators

Business Home

Biography submitted with the abstract

Michael Hecht is the Associate Director for Research Management at the MIT Haystack Observatory, and Principal Investigator for the MOXIE payload on NASA’s Mars 2020 Rover mission.Previously, he was a Senior Research Scientist at JPL, where he served as PI and Instrument Manager for the MECA instrument on the Phoenix Mars Scout mission, a soil analysis suite forinvestigating wet chemistry, microscopy, and thermophysical properties, which was originally developed in support of the human exploration.

Biography in the user profile

Author(s) and Presenter(s)

Author(s):

Dr. Michael H Hecht

4/26/2017 CIM | TPMS |

https://www.cim.org/en/TPMS­Event/Chair/ChairAbstractPool.aspx 2/2

[Unknown Title] MIT Haystack Observatory

N/A The MOXIE Team [Unknown Title]

MIT Haystack Observatory

Presenter(s):

Dr. Michael H Hecht[Unknown Title]MIT Haystack Observatory

GOT

OXYGEN?

Mars Oxygen ISRU Experiment

M i E

Jet Propulsion Laboratory California Institute of Technology

J. Mellstrom , Project Manager

ISRU & the human Mars mission

Drake (2009)

With

out I

SR

U (~

35 m

T)

How does it work?

Meyen (2015)

How does it all go together?

4

SOXE Assy Electronics

Sensor Panel

Compressor

A day in the Life

5

Version 8 (12/2/2015-jaj)

B O O T

I D L E RUN

Pump On – CO2 Flow SOXE On – O2 Production

IDLE

Send RUN CMD Sleep

RO

VER

M

OX

IE MO

DES

CAS Sensors On

20 W 20 W

0.73 MB 0.12-0.98 MB 0.01 MB

1 min 1 min 15 – 120 min 90 min

DU

RATIO

N

RA

W D

ATA R

ATE

Send SW- Selct CMD

SOXE Heaters On

Retrieve Data

<5

min

W

ake

15 min – TBD

0.12 MB

2x 10A Switch

OFF

0.0

4 M

B

Total:

PO

WER

/ENER

GY

230 W

250 W 320 Watts

350 W-hr 80-640 W-hr Energy:

30 min

Data: 1.0-1.9 MB

2x 10A Switch

ON

Time: 120-230 minutes

Power: 320 W max

Energy: 440 - 1000 W-hr

136 Bytes/s

Bold = nominal design case

0 MB

6 W-hr

Ready to Uplink Data

to Rover

Requirement Goal Threshold

Oxygen Production Rate 8 g/hr at 5 Torr, 0ºC. 6 g/hr at 5 Torr, 0ºC. Oxygen Purity 99.6% 98% Number of Cycles 20 10

Formal Requirements

System Performance

• O2 production – >1g/hr per cell (10 cells) • Operational Cycle – >45 cycles w/ no failures • O2 purity – All recent stacks exceed 99.9% • Limited by:

• Inlet flow (pump capacity, gas density at landing site) • Available power (4A limit, equiv. to 12 g/hr) • SOXE capability (10 cells, 22.7 cm2/cell)

Making O2 with SOXE

SOXE Assembly

8

Boudouard and Ni Oxidation Limits

ASR resilience to cycling

Voltage[V]

Currentdensity[A]

Voc

ASR=dV/di(Ω-cm2)

CO2 compression strategy Scroll pump chosen for real time compression to ~1 bar

without intermediate storage.

Energy efficient, can be scaled at least 10-fold. Lifetime TBD.

Performance: 83g/hr for inlet gas P=7 Torr, T= 20°C.

Stationary Scroll

Attaches Directly to

Housing

Housing

Moving Scroll

Cam Followers Limit Moving Scroll

Movement

Eccentric

Dust concern retired During operation (~100 hrs):

Airflow a few cm/s

Expect ~50 mg dust , <0.1 g/m2

Passive exposure (>10,000 hrs)

Expect 10-6 g/m2-s ~2 g/m2

Larger particles

Saltation, pebbles will be stopped by baffles

Significant pressure drops begin at 1 g/m2 for dp=0.15 μm. (Thomas et al. 1999)

Cross section correction expect no problems below ~10 g/m2

Tests confirm no effect for comparable loading with Mars simulant (2-10 μm)

Slip factor provides up to x10 additional margin

Dust exposure at Aarhus wind tunnel

Clean Passive Active

State of the Project

All except electronics & some mechanical through CDR

Extended SOXE life test now at ~50 cycles

Integrated tests exploring safe operating conditions

Outstanding issues

Electronics/software behind schedule

Some unusual (COTS) sensor behavior

On track for flight delivery in November, 2018

Flight-like engineering model to be delivered to MIT for mission support and ongoing testing ~4/19

13

Extensibility Power scaling

Mass & Volume scaling

M2020 MOXIE

Full Scale MOXIE

Where does the power go?

15

Would scale to 51 kW at 2 kg/hr!

But…

Power scaling assumptions Scales with production rate R (2000/12 (g/hr) = x167):

Electrolysis (including enthalpy) – rigorously!

Compression

Scales with # of modules (x6, 334 g/hr each, ~sixty 10x10 cm cells) Sensors

Electronics

Scales with surface area R2/3 (x30) SOXE heat loss

Expected improvements: Compression power assumed to be 70% of scaled value

Lower elevation (like MSL or VL2) gets you to 75%

Reduce output pressure

Increase utilization (more SOXE cells or CO2 recovery)

Custom DC converters improve from 83% to 90% efficient

Gas pre-heat replaced by heat exchange with exhaust

Sensor panel captures heat from, e.g., pump body

Projected power usage

Electrolysis

Compression

Heatloss

Sensors

Electronics

DCConversion

MOXIE-NG,2KG/HR,25.1KW

Consistent with DRA 5.0

Electrolysis

CompressionHeatloss

Sensors

Electronics

DCConversion

MOXIE(12G/HR,308W)

Where does the mass go?

18

Would scale to 2730 kg at 2 kg/hr!

But…

Mass scaling assumptions Scales with production rate R (x167):

SOXE cell mass

Compressor mass

Filter assembly

Scales with # of modules (x6)

Sensors

Electronics

Scales with surface area R2/3 (x30)

Thermal (insulation, etc.)

Structure

Inletassembly

Compression

SOXEcells

SOXEAssembly

ProcessM&C

Electronics

Thermal

Mechanical

MOXIE(12G/HR,16.4KG)

Inletassembly

Compression

SOXEcells

SOXEAssembly

ProcessM&C

Electronics

ThermalMechanical

MOXIE-NG,2KG/HR,1010KG

Projected mass usage

Consistent with M-WIP study

Potential improvement: Small filter assembly following dust-tolerant first stage pump

Other potential improvements

Higher temperature operation

Lower pressure operation

Higher utilization factor (low flow or CO2 re-use)

Advanced controls and improved autonomy

SMART Control

F. Meyen thesis

Special thanks to the amazing JPL Project Team!

MOXIE Testbed

Sponsors and Partners Supported by HEO/AES, STMD/Tech Demos

Mars 2020 Project managed by SMD

is brought to you by…

JetPropulsionLaboratoryCaliforniaInstituteofTechnology

M iE

JetPropulsionLaboratoryCaliforniaInstituteofTechnology

JetPropulsionLaboratoryCaliforniaInstituteofTechnologyJohnson Space Center

ISRU Technology, NASA GRC

Aarhus wind tunnel

Thank you,

Congrats & Thanks, Forrest!

GOT

OXYGEN?

Mars Oxygen ISRU Experiment

M i E

Backup: More MOXIE

25

Abstract

Essential subsystems of the Mars Oxygen ISRU Experiment (MOXIE) on NASA’s Mars 2020 mission have passed their Critical Design Review, and the project is beginning a flight build stage that will culminate in delivery of flight hardware in late 2018. Also being delivered to the MOXIE Science Team is an Engineering Model, equivalent in form, fit, and function to the flight hardware, that will support Mars 2020 mission operations and subsequent extensions of the MOXIE flight demonstration (for example, tests of long duration operation). As a scale model of a future oxygen production facility on Mars, MOXIE will generate a minimum of 6 g/hr high purity oxygen from the Martian atmosphere in at least 15 separate runs, sampling different environmental conditions on Mars, in the 2.5 years following landing of the Mars 2020 rover in February, 2021. The presentation will review the MOXIE scroll pump for CO2 collection and compression, the solid oxide electrolysis system and its packaging for CO2 conversion to O2, the monitoring and control subsystem, and the expectations for operation on Mars.

What does MOXIE do?

27

Rover Chassis

MOXIE Chassis

RAMP

Thermal & Mechanical Interface

Oxygen Plant

Intake Mars

Atmosphere

Exhaust O2, CO+CO2

Electronics Data Acquisition & Control, Power Conversion & Distribution

RPAM Power

Process Control Process Monitor

CO2 Acquisition & Compression

O2 Production Solid Oxide Electrolysis

(SOXE)

Composition Measurement

RCE Data B

RCE Data A

1:200 scale production 1:100 scale operating life

Jet Propulsion Laboratory California Institute of Technology

Mars 2020 Project

SOXE

CO2intaketocathode

O2productfromanode

CO2flo

w

throughmanifoldtocathode

CO/CO2

exhaustfromcathode

CO/CO2flow fieldovercathode

Electrode

Anode

Cathode

Electrolyte

Electrode

SOXE 11 cell stack fabricated by

Ceramatec

4 4.5 5 5.5 6 6.5 7 7.5 8Ambient pressure (Torr)

4

5

6

7

8

9

10

11

12

13

14

Max a

llow

ed O

2 p

rodu

ction

(g

/hr)

Pump capacity assuming 79 g/hr at 7.6 Torr

50% Utilization30% Utilization

29

Pump capacity (at 20°C inlet)

Predicted site highs

(dust storm)

Predicted lows

(summer night)

Predicted site highs

(fall day)

(Arrows are for VL-2 site)

Inlet filter assembly& baffle

30

Inlet Filter Assembly

Baffle

More on the Dust Story

Pressure drop of fluid with a viscosity 1.1x10-5 Pa-s, through a 0.4 mm long, 1 µm radius tube, using slip friction coefficients from 1 to 104 and inlet velocities of 0-5 cm/s

𝚫P vs. P (mbar) at constant v

6 17

0

0.4

Pressure (mbar) 𝚫

P (m

bar)

Measured result at Aarhus using laser Doppler anemometer to measure inlet velocity v.

Yet more on dust…

32

Pressure drop, ΔP, shown to scale with face velocity in Aarhus test