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Martian Moons eXploration (MMX) Japanese next-generation sample return mission

37TH MEPAG (2019)

• Launch in 2024 (TBD)

• Phobos: remote sensing & in situ observation

• Deimos: remote sensing observation (multi-flyby)

• Retrieve samples (>10 g) from Phobos & return to Earth in 2029 (TBD)

THE 1ST SAMPLE RETURN MISSION FROM THE MARTIAN SATELLITES!

WHY PHOBOS AND DEIMOS?

Regolith of Phobos/Deimos contains Martian building blocks, impactors, late accreted volatiles, ancient Martian surface components etc…

• Constrain the initial condition of the Mars-moon system

• Gain vital insight and information on the source(s) and delivery process of water (& organics) into Mars and the inner rocky planets

37TH MEPAG (2019)

MMX Science Goals

37th MEPAG (2019)

<Goal 1> To reveal the origin of the Martian moons, and then to make a progress in our

understanding of planetary system formation and of primordial material transport around

the border between the inner- and the outer-part of the early solar system

<Goal 2> To observe processes that have impacts on the evolution of the Mars system from

the new vantage point and to advance our understanding of Mars surface environment

transition

5

Mission Profile

Outward

Phobos Proximity

Return

Sun

Launch

Mars Arrival

Mars orbit

S/C Trajectory

Earth orbit

Mars Departure

2.5 hour (TBD) Stay

＜Proximity Phase＞＜Landing＞

QSO

Descent Trajectory

＜Mission Profile＞

Ascent Trajectory

Sep., 2024

Aug., 2025

Aug., 2028

July, 2029

（written above is an example, and could change in the future）

• The total of 5 years trip by use of chemical propulsion system• Interplanetary flight: 1 year for outward/homeward• Stay at curcum-Mars orbits 3 years

• Launch in 2024 • Phobos: landing• Deimos: multi-flyby• Return to Earth in 2029

37th

MEPAG

(2019)

6

Spacecraft Configuration

Launch Configuration

On-Orbit Configuration

Exploration Module

Return ModulePropulsion Module

As a result of Phase-A study, spacecraft system’s configuration and major specification are defined preliminarily.

Launch Mass : 4000kgThree stages system.Return module: 1780kgExploration module: 330kgPropulsion module: 1890kg

Mission Duration : 5 years

Sample Return Capsule

Sampler

（written above is an example, and could change in the future）

Science Instruments

500N-class OME

Landing Gear

High Gain Antenna

Propulsion Module

Return Module

Exploration Module

37th

MEPAG

(2019)

Nominal Science Payload

Payload Measurements

Wide-angle multiband camera (OROCHI)

• Global mapping of hydrated minerals, organics, and the spectral heterogeneity ofthe Martian moons

• Characterize the material distribution around the sampling sites

Telescopic camera (TENGOO) • Determine the global topography and surface structure of the Martian moons• Characterize the topography around the sampling sites

Gamma-ray, neutron spectrometer (MEGANE) (provided by NASA)

• Determine the elemental abundance beneath the surface of the Martian satellites(Provided by NASA)

Near-infrared spectrometer (MacrOmega) (provided by CNES)

• Global mapping of minerals, molecular H2O and organics of the Martian moons.• Characterize the material distribution around the sampling sites• Monitor the transport of H2O vapor, H2O/CO2clouds, and dust in the Mars

atmosphere (Provided by CNES)

Light detection and ranging (LIDAR) • Determine the Phobos shape and topography

Circum-martian dust monitor (CMDM)

• Detect and monitor: 1) the circum-Martian dust ring; 2) interplanetary dust; 3)Interstellar dust

Mass spectrum analyser (MSA) • Determine the mass and energy of ions from Phobos, Mars and Sun

Rover’s payloads (by CNES/DLR): Raman, radiometer, cameras

• Determine surface composition and physical properties

37TH MEPAG (2019)

ORIGIN OF PHOBOS AND DEIMOS

Two competing hypotheses are proposed for their origins

Capture of asteroid

Consistent with D- or T-type IR spectra

in situ formation by an impact

Consistent with low eccentricity & inclination

Image courtesy (Hiro Kurokawa)Image courtesy (Hiro Kurokawa)

37TH MEPAG (2019)


D- or T-type spectrum is consistent with the capture origin

Blue: Phobos

If Phobos & Deimos are “giant impact origin”,

the spectra reflect either

• impact-related “dark” glassy debris, or

• thin surface veneer of regolith, or

• result of space weathering

Fraeman et al. (2012)

will be tested by MMX• gamma-ray & neutron, sample analysis

37TH MEPAG (2019)

• Low eccentricity (Jacobson & Lainey, 2014)

• Phobos: 0.001511, Deimos: 0.00027

• Low inclination (Jacobson & Lainey, 2014)

• Phobos: 1.076 deg, Deimos: 1.789 deg


Low eccentricity and low inclination suggest the impact origin

If Phobos & Deimos are “capture origin”...

“Gold mine” for astrophysicists! New dynamical model to reconcile

37TH MEPAG (2019)

Visible & Near-infrared spectroscopyMacrOmega from IAS, France

• Spectrum range: 0.9-3.6 μm cf. OH = ~2.7 mm, H2O-ice = ~3-3.2 mm, organics = 3.3-3.5 mm

• Spatial resolution: 8.2 m/pix @ 20 km

Gamma-ray & Neutron spectroscopyMEGANE from APL, USA

• Elements: Mg, Fe, O, Si, Na, K, Ca, Th, U, H, C,

and Cl

• Penetration depth: up to ~1 m

REMOTE SENSING OBSERVATIONS

Distribution of “blue” and “red” units on Phobos (by MRO)~

10

km

Fe/Si/O differentiates achondritic (giant impact) and

chondritic (capture) compositions

37TH MEPAG (2019)

SAMPLE ANALYSIS: EXPECTED CHARACTERISTICS

Captured asteroid Giant impact

Petrology,

mineralogy

Unequilibrated mixture

of minerals, Hydrated

phases, Organic matter

Glassy/igneous texture,

High-T phases

Bulk chemistry Chondritic, Volatile-rich Volatile-poor

IsotopesPrimitive solar-system

signature

Mixed feature between

Mars and impactor

Oxygen and Cr isotopic compositions

Mars

Earth

achondrite

O-chondrite

CI

CR

CM

CV

CO

CV

CK

CO

Non-carbonaceous

Carbonaceous

Data compilation (R. Fukai)

37TH MEPAG (2019)

Coordinated in-situ and bulk analyses will provide constraints on the origin(s) of the returned samples

CONCLUSIONS

• The MMX spacecraft is scheduled to be launched in 2024, and return >10 g of Phobos

regolith back to Earth in 2029 (TBD)

• The origin(s) of Phobos and Deimos has been in debate: captured asteroid or in situ

formation by impact

• MMX will provide clues to their origins and offer an opportunity to directly explore the

building blocks, juvenile crust/mantle components, and late accreted volatiles of Mars

MMX will constrain the initial condition of the Mars-moon system,

and shed light on the source, timing and delivery process of water (& organics) into

the inner rocky planets

37TH MEPAG (2019)

SLIDES FOR QUESTIONS

MARTIAN SAMPLES ON PHOBOS?

Mars impact ejecta could exist in the regolith of Phobos

Numerical simulation (Ramsley & Head, 2013)

Mars ejecta on Phobos is expected to• experience much lower launch velocity

than Martian meteorites

⇒ preserve original information?

• contain a variety of ancient sedimentary

materials (with organics??)

⇒ cf. Martian meteorite = igneous rocks

Spray of impact ejecta on the Phobos orbit

37TH MEPAG (2019)

Phobos regolith provides a wealth of information on the ancient surface environments of Mars

in lake-bed mudstone at Gale crater

TWO SYNERGISTIC SAMPLING SYSTEMS

37TH MEPAG (2019)

Coring & pneumatic sampling maximizes MMX sample science

Core samplerAccess to Phobos building blocks beneath the surface (>2 cm)

Pneumatic samplerSelective sampling of Phobos surface veneer(incl. Martian samples!)

Martian Moons eXploration (MMX) Japanese next-generation sample return mission

• Launch in 2024 (TBD)

• Phobos: remote sensing & in situ observation

• Deimos: remote sensing observation (multi-flyby)

• Retrieve samples (>10 g) from Phobos & return to Earth in 2029 (TBD)

THE 1ST SAMPLE RETURN MISSION FROM THE MARTIAN SATELLITES!

37TH MEPAG (2019)

WHY MARS & ITS SATELLITES?–Geophysical & Geochemical Constraints–

37TH MEPAG (2019)

Mars represents a planetary embryo accreted <10 Myr after SS birth

Walsh et al. (2011); Dauphas & Pourmand (2011)

Mas

s Ear

th

0.1

1.0

Mars

Results of dynamical simulation Accretion timescale inferred from 182Hf–182W systematics

Model depends on

Hf/W ratio of the mantle

WHY MARS & ITS SATELLITES?–Geophysical & Geochemical Constraints –

37TH MEPAG (2019)

Martian mantle differentiated early & did not experienced global mixing

Kruijer et al. (2017)

Timing of Mars differentiation Coupled εNd-εW isotopic systematics

preserve source heterogeneity

formed early in the MO

MO differentiation

occurred within the first 50

Myr

146 S

m-14

2 Nd

syst

em (

silic

ate

diffe

rent

iatio

n)

182Hf-182W system (metal-silicate differentiation)

SATELLITES ARE MADE OF MARTIAN JUVENILE CRUST & MANTLE?

37TH MEPAG (2019)

Contains >35% of Martian materials; most come from the mantle!

Results of high-res. SPH simulation (Hyodo, Genda+, 2017)

Disk mass fraction vs. impact angle

Impactor

Martian

Cumulative fraction of disk particles and their original depth from the surface of Mars

>4RMars

cf. typical crust thickness = 30-60 km

WHY MARS & ITS SATELLITES?–Geological & Geochemical Constraints–

Martian surface records the historical evolution of environments

37TH MEPAG (2019)

Global distribution of aqueous minerals (Ehlmann & Edwards, 2014)

4 Ga 2 Ga Present

claycarbonate

sulfate/anhydrous

surface water

?

1

0oce

an

de

pth

[km

]a

lte

ratio

nm

ine

rals

H2O

H, H2

H2O

2, O

3

to space

to surface

Relationship btw water volume & aq. alteration minerals

WHY PHOBOS AND DEIMOS?

Regolith of Phobos/Deimos contains Martian building blocks, impactors, late accreted volatiles, ancient Martian surface components etc…

• Constrain the initial condition of the Mars-moon system

• Gain vital insight and information on the source(s) and delivery process of water (& organics) into Mars and the inner rocky planets

37TH MEPAG (2019)

MMX Science Goals

Goal 1:

• To reveal the origin of the Mars’ moons, and then to make a progress in our understanding of planetary system formation and of primordial material transport around the border between the inner-and the outer parts of the early solar system.

Goal 2:

• To observe processes that have impacts on the evolution of the Mars system, from the new vantage point and to advance our understanding of Mars surface environmental transition.

37TH MEPAG (2019)

MMX Science Objectives

Goal 1: (origin, formation, transport)

1.1 To determine whether the origin of Phobos is captured asteroid or giant impact.

1.2a (In the case of captured asteroid origin) To understand the primordial material delivery process (composition, migiration history, etc.) to the rocky planet region and to constrain the initial condition of the Mars surface environment evolution.

1.2b (In the case of giant impact origin) To understand the satellite formation via giant impact and to evaluate the how the initial evolution of the Mars environment was affected by the moon forming event

1.3 To constrain the origin of Deimos

Goal 2: (evolution)

2.1 To obtain a basic picture of surface processes of the airless small body on the orbit around Mars

2.2 To gain new insight on Mars surface environment evolution

2.3 To better understand behavior of the Mars air-ground system and the water-cycle dynamics

37TH MEPAG (2019)

37TH MEPAG (2019)

DeMeo & Carry (2014)

SIGNIFICANCE OF MMX

MMX will constrain more than the satellite origin

Giant impact

Asteroid capture

• Juvenile crust & mantle

• Internal structure

Historical migration of solar system bodies

• Material distribution/migration

• Asteroidal variation

(S. Tachibana)



Petrology,

mineralogy

Unequilibrated mixture of

minerals, Hydrated



High-T & -P phases



signature


Mars and impactor Taylor (2010)

by remote sensing, in situ & sample analysis

37TH MEPAG (2019)


Petrology,

mineralogy


minerals, Hydrated



High-T phases



signature


Mars and impactor


Peplowski et al. (2011)

Compositions of terrestrial planets and the Moon

Mars


Po

tass

ium

(p

pm

)Thorium (ppm)

(S. Tachibana)

37TH MEPAG (2019)

FLOW CHART FOR DETERMINING THE ORIGIN OF PHOBOS

Origin of returned sample

Asteroidal origin

Mixture of

Asteroidal/Martian

Martian origin

Origin of Phobos

Yes

No

Capture of asteroid

formed in the outer

solar system Martian sample: GI origin?e.g. old age, high-T, volatile-free

In situ formation by

a giant impact on

Mars

Check the representativeness of the returned sample


37TH MEPAG (2019)

MEGANE IDENTIFIES PHOBOS ORIGIN

Lawrence+ (2018)

37TH MEPAG (2019)

LIST OF “KEY” ANALYSIS FOR THE RETURNED SAMPLE

Method Data type sample amount Notes

SIMS O, H, (C, S, etc.) isotopes ~10 μm dia. in-situ, destructive but limited to meas.

spot

IRMS O (C, S, N) isotopes <1 mg Bulk, destructive

IRMS Ar-Ar age <0.01 mg Bulk, destructive

TIMS Rb-Sr age ~10 mg Bulk, destructive

SIMS Mn-Cr age ~10 μm dia. in-situ, destructive but limited to meas.

spot

PGA/NAA Bulk chemistry ~1 g Bulk, non-destructive

ICP-MS Bulk chemistry ~10 mg Bulk, destructive

EPMA/TEM/Raman Mineral chemistry,

crystallography

<3 μm dia. in-situ, non-destructive

XAFS Chemical speciation ~1-10 μm dia. in-situ, non-destructive

SQUID

spectroscopy

Magnetic field ~1 μm dia. in-situ, non-destructive


37TH MEPAG (2019)

Regolith Particle Size

37TH MEPAG (2019)

1 µm

Lower limit of radiation pressure theory

70 µm 250 µm 1 cm1-3 mm

Particle size

Typical Itokawa regolith

Typical lunar regolith

Micro-particle in Itokawa sample

likely range

most likely?

・ Phobos regolith will be larger than the lunar regolith, and smaller than Itokawa

regolith. It is expected to be 70–1000 µm.

・Most particles are around 300 µm due to the radiation pressure segregation?

Personal comm. (K. Ogawa)

MMX Science Goals

37th MEPAG (2019)

<Goal 1> To reveal the origin of the Martian moons, and then to make a progress in our

understanding of planetary system formation and of primordial material transport around

the border between the inner- and the outer-part of the early solar system

<Goal 2> To observe processes that have impacts on the evolution of the Mars system from

the new vantage point and to advance our understanding of Mars surface environment

transition

International Collaboration

ESA

• JAXA and ESA are going to make a official agreement on MMX

• Ka-band communication equipment

• Ground station for data downlink

• Scientific involvement

NASA

• JAXA and NASA exchanged Letter of Agreement on MMX

• NASA issued an AO that solicits proposal for Gamma-ray and Neutron Spectrometer and selected MEGANE of JHU/APL

• Other items (DSN support, test facilities usage, etc.) are under discussion

37TH MEPAG (2019)

International Collaboration, cont.

CNES• JAXA and CNES made Implementing Arrangement on MMX

• Near-infrared Spectrometer (MacrOmega)• Flight dynamics• Feasibility of the small lander/rover to be equipped (w/DLR)

DLR• Collaboration items are under the discussion

• Experiments using the Bremen Drop Tower• Experiments using German facilities for landing mobility• Study and development of robotic arms• Feasibility of the small lander/rover to be equipped (w/ CNES)

37TH MEPAG (2019)

(S. Tachibana)



Petrology,

mineralogy


minerals, Hydrated



High-T & -P phases



signature

Mixed feature between Mars and

impactor Taylor (2010)


37TH MEPAG (2019)


Petrology,

mineralogy


minerals, Hydrated



High-T phases



signature

Mixed feature between Mars and

impactor


Peplowski et al. (2011)

Compositions of terrestrial planets and the Moon

Mars


Po

tass

ium

(p

pm

)Thorium (ppm)

(S. Tachibana)

37TH MEPAG (2019)

FLOW CHART FOR DETERMINING THE ORIGIN OF PHOBOS

Origin of returned sample

Asteroidal origin

Mixture of

Asteroidal/Martian

Martian origin

Origin of Phobos

Yes

No

Capture of asteroid

formed in the outer

solar system Martian sample: GI origin?e.g. old age, high-T, volatile-free

In situ formation by

a giant impact on

Mars



37TH MEPAG (2019)

MEGANE IDENTIFIES PHOBOS ORIGIN

Lawrence+ (2018)

37TH MEPAG (2019)

Regolith Particle Size

1 µm

Lower limit of radiation pressure theory

70 µm 250 µm 1 cm1-3 mm

Particle size

Typical Itokawa regolith

Typical lunar regolith

Micro-particle in Itokawa sample

likely range

most likely?

・ Phobos regolith will be larger than the lunar regolith, and smaller than Itokawa

regolith. It is expected to be 70–1000 µm.

・Most particles are around 300 µm due to the radiation pressure segregation?

Personal comm. (K. Ogawa)

37TH MEPAG (2019)

SAMPLE ANALYSIS: FLOW CHART

• ~1,000 grains for initial screeningFYI: ~1,000 grains = ~1 g (for ~0.3 mm size grain)

• ~100 grains for detailed petrology, mineralogy, in situ isotope analyses

• ~10 to 20 grains for bulk isotope analyses

~1 g for the MMX team

>9 g for the int. community!

37TH MEPAG (2019)

LIST OF “KEY” ANALYSIS FOR THE RETURNED SAMPLE

Method Data type sample amount Notes

SIMS O, H, (C, S, etc.) isotopes ~10 μm dia. in-situ, destructive but limited to meas.

spot

IRMS O (C, S, N) isotopes <1 mg Bulk, destructive

TIMS, ICP-MS Cr, Ti isotope <10 mg Bulk, destructive

TIMS, ICP-MS Rb-Sr, Sm-Nd, Pb-Pb age ~10 mg Bulk, destructive

SIMS Mn-Cr age ~10 μm dia. in-situ, destructive but limited to meas.

spot

IRMS Ar-Ar age <0.01 mg Bulk, destructive

PGA/NAA Bulk chemistry ~1 g Bulk, non-destructive

ICP-MS Bulk chemistry ~10 mg Bulk, destructive

EPMA/TEM/Raman Mineral chemistry,

crystallography

<3 μm dia. in-situ, non-destructive

XAFS Chemical speciation ~1-10 μm dia. in-situ, non-destructive

SQUID

spectroscopy

Magnetic field ~1 μm dia. in-situ, non-destructive


Formation age of the moon (or asteroid)

Age distribution of impacts

Regolith physical properties

37TH MEPAG (2019)

Origin of the moon

42

MMX-RoverP. Michel, S. Ulamec

Actual Rover design and Payload:

• Overall Rover with 29,1 kg including margin and 4 Payloads:• Raman Spectrometer, RAX (PI: Ute Böttger, DLR)• Radiometer, miniRAD (PI: Matthias Grott, DLR)• NavCAM (PI: Pierre Vernazza, LAM)• WheelCAM (PI: Naomi Murdoch, ISAE-SUPAERO)

• Optional Payload, considered during phase B:• Gravimeter, GRASSE (PI: Ö. Karatekin)• GPR, GRAMM (PI: D. Plettemeier)

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