¹äÍöĀȩɎɜɑȺʯȪɍț
ĸnĝ&ŲɌɅȮɇCandidates for landing sites
for the Hayabusa2 missionǡǟǠǧ¢ǧéǡǢàAugust 23, 2018ǳǫǽǫǘɎɜɑȺǡʏʡɹɫɱʅJAXA Hayabusa2 Projectïàɍ4ǞTopicsȩɎɜɑȺʯȪɌƸƣȻɇȧʥĸnĝɍ&ŲʩɾʁʀɿɪʣȱɝɐǵǫǹǭǷǺʥǵǲǶǯǸǻǫǜǲǲɍĸnĝ&ŲʪɌɅȮɇŒȽɠȨRegarding Hayabusa2:
ʥCandidates for landing sites for
touchdown, MASCOT, and MINERVA-IIǡĴāʭʬȩɎɜɑȺʯȪûŵʥʖʁɸʜʣɍĒɡûŵʮʬʏʡɹɫɱʅɍĨĥɉ2ɺɳɹʛʦʟ
ʯʬĸn&Ųnĝɉ àʰʬɾʁʀɿɪʣ&ŲnĝƬʱʬɾʁʀɿɪʣ&ŲnĝɌɅȮɇɍŀĳøŽʲʬǵǫǹǭǷǺɍĸn&ŲnĝƬʳʬǵǲǶǯǸǻǫǜǲǲɍĸn&ŲnĝƬʴʬĸƽĨɌ`ȶɂÀİʵʬ¯ɍ ǢContents
0. Hayabusa2 & mission flow outline
1. Project status & overall schedule
2. Landing site candidates and expected dates
3. Selection of touchdown site candidates
4. Science discussions for touchdown site candidates
5. Selection of landing site candidates for MASCOT
6. Selection of landing site candidates for MINERVA-II
7. Strategy toward the successful touchdown
8. Future plansǣȩɎɜɑȺʯȪûŵĴĳȩɎɜɑȺȪȳÍöȻɂǹq¹äɨʅɯʢɝɟɛQĳɋɾɨʏɈȭɠǭq¹äʞʛɪɲɪɍÍöSɐɶʣʏʟʞɾʦʣɤūȮȧQ}ƿ
ōɌȱȶɠƳĢʥĆʥêĀĢɍĶĭɍŻãȽɠȸɉɈȧnĩʥēʥīdɍƏĘɉƤIɌƝɠɉɉɛɌȧȩɎɜɑȺȪɈƀȻɂĔ¬±ÍöÆŬɤŘÉʥĲȺȾɇȧï9ƱɈįɤĤ¥ȽɠȨì®Ⱥɡɠ¿õɉEõʥĆɜêĀĢɌəǭq¹äɍÍöɌɝɟȧnĩʥēʥīdɍQðÚƷɍĶĭɉƤIɤŻãȻȧ}ƿōŀɤĲȺȾɠȨʥŭŅŰşɌɝɄɇī¿ȺɡɠɱʠʦɾʦƛȲɞɍɶʣʏʟÌVɉȮȯÝɂɋÊÀɛūȯȸɉɈȧàïȳȸɍ9ƱɌȱȮɇȧȺɞɌįɤʞʦʆȽɠȨ
ʥ}ƿō|¬±Íöɍ ȻɂÆŬɤļņȽɠȨģŧʶʥį;ɍǭq²nĩÎƛ¹äɍɶʣʏʟʞɾʦʣɈȭɠȨʥ¹äɌʝʣʄʎʦȻɋȳɞŭŅŰşɤŭŅȺȾɇȧɀɍB¯ɤŹėȽɠɉȮȯį;ɍƂɘɤūȯȨʥȩɎɜɑȺȪɍÍö¿õɉ]ɣȾɠȸɉɈȧ}ƿō4ɍĢƍ9ɜƏĘɉƤIƦłɌɅȮɇȧɝɟĔȵĹɠȸɉȳɈȴɠȨlǁĳşɆȶʶʥàïȳ/ǏɌņɄɂQ|Íöɍ9ƱɈȧǭq¹äɉȮȯÝɂɋnĝɒ?ƨȺȾɠȨʥȩɎɜɑȺȪÍöĀɌɝɄɇ°ɂĦŤ·ɉ-·ɤĲÓȻȧàïɍ¹
äŀSɐ}ƿōÍöÆŬɍƤɤkɠɉɉɛɌȧQ|ÍöɍʍʡʣʃɧɦɤÈȵȨʥǶǫǹǫɌȱȮɇɛȧ¹äɶʣʏʟʞɾʦʣʖʁɸʜʣǷǹǲǸǲǹǜǸǯȓǘ ʩÅȷʶ¡¿ǡǧ¢ȧ¹ä?ĸʶ¡¿Ǣǟ¢ȧnĩƭʶ¡¿ǢǤ¢ʪȳßȺɡɇȱɟȧɶʣʏʟɍÒȳVɟĉɚɞɡɇȮɠȸɉɌDȰɇŀŢɍĶĒȳūɣɡɇȱɟȧ Ţɍ¿õɤĄƗʥøƀȽɠȸɉɌɝɠŀĳ¿õɛì®ȺɡɇȮɠȨǤʩɨʝɺʅǘĈŇűąʪǘɎɜɑȺʯǘ ŵŚ.ǘƍƲǘǘȦŎǘǥǟǨȇȄÅȷǘȦ¡¿ǡǥ¢ʩǡǟǠǣ¢ʪǠǡéǢàƔƧǘȦȦǘ
¹ä¬±
¹ä?ĸ ¡¿Ǣǟ¢ʩǡǟǠǧ¢ʪnĩƭȦ ¡¿Ǣǡ¢ʩǡǟǡǟ¢ʪ
¹äĚmìƷȦȦŎǠǧʤéÍöƋ|ǘnĩÎƛ¹äȦǸȔȐȄȐʩʞʛɪɲɪʪ
ŵÔƘĀf
ɶʣʏʞʣɲĀüȧnĩƭɯʏɼʟȧ0ɯʘʝȧʠʦɷʦėƑżȧŀŹėĀfʩƛƎxȧ ƷƎxʪȧŭŅŰşȧqʡʦʉǤOverview of Hayabusa2
ObjectiveWe will explore and sample the C-type asteroid Ryugu, which is a more primitive
type than the S-type asteroid Itokawa that Hayabusa explored, and elucidate
interactions between minerals, water, and organic matter in the primitive solar
system. By doing so, we will learn about the origin and evolution of Earth, theoceans, and life, and maintain and develop the technologies for deep-space return
exploration (as demonstrated with Hayabusa), a field in which Japan leads theworld.

Expected results and effects
ʥBy exploring a C-type asteroid, which is rich in water and organic materials, wewill clarify interactions between the building blocks of Earth and the evolution of
its oceans and life, thereby developing solar system science.ʥ Japan will further its worldwide lead in this field by taking on the new challenge ofobtaining samples from a crater produced by an impacting device.
ʥWe will establish stable technologies for return exploration of solar-system bodies.

Features:ʥWorld’s first sample return mission to a C-type asteroid.
ʥWorld’s first attempt at a rendezvous with an asteroid and performance ofobservation before and after projectile impact from an impactor.
ʥComparison with results from Hayabusa will allow deeper understanding of the
distribution, origins, and evolution of materials in the solar system.

International positioningʶʥJapan is a leader in the field of primitive body exploration, and visiting a type-C
asteroid marks a new accomplishment.
ʥThis mission builds on the originality and successes of the Hayabusa mission. In
addition to developing planetary science and solar system exploration
technologies in Japan, this mission develops new frontiers in exploration ofprimitive heavenly bodies.
ʥNASA too is conducting an asteroid sample return mission, OSIRIS-REx (launch:
2016; asteroid arrival: 2018; Earth return: 2023). We will exchange samples andotherwise promote scientific exchange, and expect further scientific findings
through comparison and investigation of the results from both missions.

(Illustration: Akihiro Ikeshita)
Hayabusa 2 primary specifications
Mass
Approx. 609 kg
Launch3 Dec 2014
MissionAsteroid return
Arrival27 June 2018
Earth return2020
Stay at asteroid
Approx. 18 months
Target body
Near-Earth asteroid Ryugu
Primary instruments
Sampling mechanism, re-entry capsule, optical cameras, laser range-finder,
scientific observation equipment (near-infrared, thermal infrared), impactor,
miniature rovers.

ǥʖʁɸʜʣɍĒɡûŵÅȷǡǟǠǣ¢ǠǡéǢàȦȤnĩɺɨʣɲʉɨ
ǡǟǠǤ¢ǠǡéǢà

¹ä?ĸ
ǡǟǠǧ¢ǥéǡǦàʞʙʦʅɼʣɸʣɲŹėɌɝɄɇȧ¹äɤƇɓɠȨɀɍ¯ȧqʡʦʉɜqĸƽĀɤ:ɟǅȽȨȺɞɌŮǉȲɞɶʣʏ
ʟɤV°ȽɠȨnĩƭǡǟǡǟ¢îȹɢ

¹ä8Ĳ
ǡǟǠǨ¢ǠǠǜǠǡéʽˁʻʿʻ
ɍī¿ɶʣʏʟ9ôʩɨʝɺʅǘĈŇűąʪǘ

2ɤļƄ¯ȧɱʠʦɾʦɌɾ
ʁʀɿɪʣɤūȮȧnĢƍɤÌVȽɠȨŭŅŰş×8ŭŅŰşɌɝɄɇȧ¹äŮǉɌĳɋɱʠʦɾʦɤɠȨǦMission flow
Launch3 Dec 2014

Arrival at asteroid
ǳune 27, 2018Ȧ▲
Earth swing-by
3 Dec 2015

Examine the asteroid by remote sensing
observations. Next, release a small lander androver and also obtain samples from the surface.

Earth returnlate 2020

Depart asteroid
Nov–Dec 2019

Create artificial
craterSample analysis(Illustrations: Akihiro Ikeshita)

After confirming safety, touchdown
within the crater and obtain
subsurface samples

Releaseimpactor

Use an impactor to create
an artificial crater on theasteroid’s surfaceǧʮʬʏʡɹɫɱʅɍĨĥɉț
2ɺɳɹʛʦʟ

Ĩĥʶǘǘ
– ǧéǤàȲɞɎưCėɍɂɚɍƥĭɤƶȻȧǧéǦàɍǧǩǠǟǋʩàïæƷʪɌȱȮɇèǕ¤ǧǤǠȉɗɈÎƛȻɂȨɀɍ¯ȧǧéǠǟ
àɌʒʦʗʔɹɸʜʣɌ±ȻɂȨ– ȸɡɗɈV°ȺɡɂʄʦɾɌsɆȮɇȧĸnĝɍøŽɤūɄɂȨ– ǧéǠǧàȲɞǬȋȓǜǬƥĭɤƶȻɂȨʩǨéǦàɌǬȋȓǜǫɌÂɠ ʪ
2ɺɳɹʛʦʟʶǘǘ
2015
3

12

CNPK

2016
10 12

ǯǮǻǯǰǫ

;ìƥĭ

B
ǙǠǡéǢàǚ2017

2018

4

12

ICPGLCǙǠǡéǢàǚ*@=1=
ǙǠǠʺǠǡéǚ*@=1=
ǙǥéǡǦàǚǯǹǫʩǵǴǰǞ
ǼǴǱʪƂǔƥĭ 
ǙǤéǡǠàǛǡǡàǚ  '&%#
Ǡǟé
Ǥé

6Ņ112


ƭƥĭ

¹äƛÎƥĭ¹äƫŁƥĭǢé Ǥé2020

6 7

Îƛ

ʾʼ˂ʽ˃
ˀ˃ʼ

CEPDPHPA Ǣé ǥé

2019

FMJO
Ǚǡǟǡǟ¢îȹɢǚ  Ǥé ǥé ǠǠé Ǡǡé
ǠǠé

ǣé

Ǡé

ǥé

ǺǬǮ

ǺǬǮ

ǺǬǮ ǺǬǮǨ

1. Current project status& schedule overview

Current statusʶǘǘ– On August 5, we began operations for gravity measurement, approaching
Ryugu to an altitude minimum of 851m at around 08:10 JST on August 7.
The spacecraft then returned to the home position on August 10.
– Based on the data obtained to date, we investigated possible landing points.
– BOX-B operations began on August 18 (scheduled to return to BOX-A on
September 7).

Schedule overview:
2015
3

12

Event

ǲȊȆȏȆǾȈǘ
ȋȌȂȍǾȏȆȋȊ

2016
10 12

ǯǮǻǯǰǫ5,=7.2ǘǘǙǮȂȀǘǢǚ2017

4ǵǾȍ ǳȐȊ

::3>,5,<*@=1=ǙǳȐȊȂǘǡǦǚǶȋȑ2020
12ǸȂǜȂȊȏ12ȍȔǯǾȍȏȅǘȍȂȏȐȍȊǫȎȏȂȍȋȆȁǘȌȍȋȓȆȉȆȏȔǘȋȌȂȍǾȏȆȋȊȎ",:<2;?371-@ǙǮȂȀǘǢǚǵǾȍ ǵǾȔ

2019

6 7ǾȌȌȍȋǾȀȅǳȋȐȍȊȂȔǘȏȋǘǾȎȏȂȍȋȆȁȎȒȆȊȄǜǿȔǯǹǫʩǵǴǰǞǼǴǱʪȏȂȎȏǘȋȌȂȍǾȏȆȋȊȎ +8=<2/:72/63;92/:/;<,<387
89/:,<387; '&%#ǙǵǾȔǘǡǠǜǘǡǡǚ
ǷȀȏ
ǵǾȔ

$87/7137/89/:,<387;A

2018

!/9,:<=:/0:86*@=1=ǙǶȋȑʺǮȂȀǚ,9;=5/://7<:@ǙǴǾȏȂǘǡǟǡǟǚ(9<3.,57,>31,<387 +85,:.874=7.<387ǵǾȔ ǳȐȈ ǶȋȑǮȂȀ
ǫȌȍ

ǳǾȊ

ǳȐȊ

ǺǬǮ

ǺǬǮǺǬǮ

ǺǬǮ

Ǡǟ

ïƌÚɌȱȶɠďºĝ
¹äɍ`ȴɌďºʧïƌÚɈɎȧơ ɍnkɉ^ýɌȧJɤɌȻɇÐȮɇȮɗȽȨʞʛɪɲɪȳƟūŤƕȻɇȮɠȸɉɌɝɟȧʞʛɪɲɪɍșJȚɎɍkɍ(ɌɋɠɍɈȧȳƟɌɋɟɗȽȨ¯ɎȧĮ+aɚɇJɤɌȻɗȽȨJùȸɡɗɈɍ3ƶĮ+Ɏȧ}ƿō
ɌȱȮɇJ(ʩnĩɍJùȳȭɠÞʪɤɌȻɇÐȮɇȮȴɗȻɂȨ

nĩɍJù

Jù
ʩ©JAXAʪʩ©JAXAȧđ{ɋɊʪʞʛɪɲɪɎŤƕȳƟ`ȴʩƟūʪʞʛɪɲɪɍșnkȚɍǠǠ

Points to note in this documentPay attention to the orientation of the asteroid!

Public images so far have shown
the northern direction of the Solar
System (direction of the Earth’s
North Pole) pointing upwards.

In this document, like a typical map, north isdrawn pointing upwards. As Ryugu rotates
backwards, Ryugu’s “north” is at the bottom of
the left-hand figure, but the top in this map (topand bottom are reversed).
From now on, public images also show thenorthern direction of Ryugu pointing upwards.
north pole

Earth
North Pole

north poleʩ©JAXAȧU. of Aizu et al.ʪ

Ryugu has a reverse rotation (retrograde)ʩ©JAXAʪ

Example of a Ryugu “map”

Ǡǡʯʬĸn&Ųnĝɉ àĸƽnĝƬʩLSSʶLanding(Site(Selec-onʪƊ(Ȧʥ2018¢8é17àɌƶ)(ȦʥRDŢ(109ʩʞʙʦʅRDŢɤaəʪ(ȦʥxlɍRDŢ39ʷDLRɝɟ14ȧCNESɝɟ2ȧNASAɝɟ2ʸ(ȦʥƊƈɎLB10æȲɞL¯7æɗɈūɣɡɂ(ȦȦȦ↓ȦȦȦȦ(ɾʁʀɿɪʣȧMASCOTȧMINERVACIIɍĸn&ŲnĝɤĉȻɂ((ʩ©JAXAʪ

2018¢8é17àȦLSSƊɍǃ]7ķǠǢ

2. Landing site candidates andexpected dates
Landing Site SelectionʩLSS) conference:ȦʥHeld on August 17, 2018
Ȧʥ109 attendees (including remote participants)Ȧʥ39 participants from overseas (14 from DLR, 2 from CNES and 2 from NASA)ȦʥDiscussion took place from 10 am to 7 pm.ȦȦȦȦȦȦ
↓Determined candidate landing points for spacecraft touchdown, MASCOT & MINERVA-IIʩ©JAXAʪ

August 17, 2018: Group photo of LSS meetingǠǣʯʬĸn&Ųnĝɉ àĉȺɡɂĸn&Ųnĝ(ȦȦȦɾʁʀɿɪʣȦȦȦʶ(L08ʩʉʁɱɦʁʏʶL07ȧM04ʪ(ȦȦȦMASCOTȦȦȦȦȦǘʶ(MAC9(ȦȦȦMINERVACIIC1ȦȦǘʶ(N6ʩ©JAXAȧó{ɋɊʪǠǤ

2. Landing site candidates andexpected dates
Determined landing site candidatesȦȦȦTouchdownʶ L08ʩbackupʶL07ȧM04ʪȦȦȦMASCOTʶ MA-9ȦȦȦMINERVA-II-1 ʶ N6

ʩ©JAXA, University of Tokyo & collaboratorsʪǠǥʯʬĸn&Ųnĝɉ àĉȺɡɂĸn&Ųnĝ(ȦȦȦɾʁʀɿɪʣȦȦȦʶ(L08ʩʉʁɱɦʁʏʶL07ȧM04ʪ(ȦȦȦMASCOTȦȦȦȦȦǘʶ(MAC9(ȦȦȦMINERVACIIC1ȦȦǘʶ(N6ɾʁʀɿɪʣ

MASCOT

MINERVA-II-ʮʩ©JAXAȧó{ɋɊʪǠǦ

2. Landing site candidates andexpected dates
Determined landing site candidatesȦȦȦTouchdownʶǘL08ʩbackupʶL07ȧM04ʪȦȦȦMASCOTʶ MA-9ȦȦȦMINERVA-II-1 ʶ N6
Touchdownʩ©JAXA, University of Tokyo & collaboratorsʪ

MASCOT

MINERVA-II-ʮǠǧʯʬĸn&Ųnĝɉ àƥĭ à(
ȦȦȦɾʁʀɿɪʣʮʞʈʦɶʟʮʶ9é11à12à(ȦȦȦȦȦȦȦȦȦȦʩèĝ?ʶ9é12àʪ(ȦȦȦMINERVACIIC1ƥĭȦȦȦȦȦǘʶ9é20à21à(ȦȦȦȦȦȦȦȦȦȦʩMINERVACIIC19ǅʶ9é21àʪ(ȦȦȦMASCOTƥĭȦȦȦȦȦȦȦȦǘʶ10é2à4à(ȦȦȦȦȦȦȦȦȦȦʩMASCOT9ǅʶ10é3àʪ(ȦȦȦɾʁʀɿɪʣʮʞʈʦɶʟʯʶ10é á(ȦȦȦɾʁʀɿɪʣʮȦȦȦȦȦȦȦȦʶ10éá((ďºʶƥĭɍàɎwçɌɋɠu]ȳȭɟɗȽȨǠǨ

2. Landing site candidates andexpected dates

Operation ScheduleȦȦȦTouchdown 1 rehearsal 1:
September 11 ~ 12ȦȦȦȦȦȦȦȦȦʩArrival at lowest altitude : September 12ʪȦȦȦMINERVA-II-1 operation:
September 20 ~ 21ȦȦȦȦȦȦȦȦȦʩMINERVA-II-1 separationʶSeptember 21ʪȦȦȦMASCOT operation:
October 2 ~ 4ȦȦȦȦȦȦȦȦȦʩMASCOT separationʶOctober 3ʪ
Touchdown 1 rehearsal 2:ȦȦȦTouchdown 1:

mid-Octoberlate-OctoberNote: date of operations may be changed. ǡǟʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&ŲnĝɍBÑñ—ɀɍʮ(ÍöĀȳĸƽɈȴɠ|ɍŊjÍöĀɎnĩɉʞʛɪɲɪɤŔɑśɌċɄɇŁFɈȴɠȨȦȦ↓ÍöĀȳĸnɈȴɠɍɎȧʞʛɪɲɪɍƎƧɤ ´ɉȻɇNJɌ
ɀɡɁɡ200mł¤ɍǎrʩŜ¤Ɉ±30°ł¤ɍŊjʪƎƧɤËɥɈNJɌ(ɀɡɁɡ200mɔɊ(ʩŜ¤Ɉ±30¤ɔɊʪ

}ƿ
ÍöĀ
nĩ

ÍöĀɍFȴŤƕƖʩ©JAXAȧó{ɋɊʪǡǠ

3. Selection of touchdown site candidates
Prerequisites for touchdown candidate points, part 1
Range on the celestial body where the spacecraft can land
The spacecraft can move along the line connecting the Earth and Ryugu.
ȦȦ↓The region where the spacecraft can land is the area within about 200 m to the north andsouth of Ryugu’s equator (range of about ±30° latitude)

Within(200m(north(and(south(of(the(equator((about(±30° latitude)

Spacecraft

rotation axis

ʩ©JAXAȧU. of Aizu et al.)

Sun
Earth

Spacecraft
movementǡǡʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&ŲnĝɍBÑñ—ɀɍʯ(ÍöĀȳĸƽɈȴɠŮǉɍñ(1) ¡oÛ¤30¤4ȜȦȦȦǘǘȦ ←}ƿǆĈɍʊʆʟɍ`ȴɍ@ƻ(2) ĵ­100mɍ¡pƮ9ȦȦȦȦ ←ťčƅɍŌ¤(3) ʓʟɿʦɎǕȺ50cmȦȦ←ɶʣʏʝʦʒʦʣɍƵȺ(4) ŖĖ¤370Kʩ97ȝʪ¤←ĀfɍFĖ¤Ŋj#ÉȜ ȸɍź¤

}ƿ
ÍöĀ
nĩ

¹ä

ÍöĀɍFȴǡǢ

3. Selection of touchdown site candidatesPrerequisites for touchdown candidate points, part 2
Surface conditions suitable for landing(1) Average slope within 30° Ȝ ← Limit due to orientation of solar panels (2) Flat region with 100m diameter ← Navigation guidance accuracy
(3) Boulder height less than 50cmȦ← Length of sampler horn
(4) Absolute temperature less than 370Kʩ97ȝʪȦ← Within operating temperature range of equipment Ȝ ʹhis angle

Sun
Spacecraft

Earth

asteroidSpacecraft movementǡǣʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&ŲnĝɍŕɟƚɘɍÄǍ(Ȧň1ă
ăǀʶ 2¤ɺɴɦŻô

Box-A, Box-C,Ǖ¤! Ťƕʙʄʟ! ©ĥʙʄʟ

ň2ăăǀʶĮ+ɌɝɠƁ"! 0ťčɯʘʝɌɝɠĮ+ň3ăăǀʶĨ·Żô

Box-AʶǕ¤20km
Box-CʶǕ¤6kmǕ¤ʶǕ¤5km

! Ė¤9k! ŮǉÎƛɍœ¤!·! ʓʟɿʦʩvʪ¤ÍöĀɍGɍ`ȴȧŮǉɍ*ȴȧŮǉɍʄɴʓɴ¤ɋɊȲɞȧĸƽɌɉɄɇ 2ɋuÃɤƬɑ0ťčɯʘʝɍĮ+ȲɞȧʓʟɿʦʩvʪɍƲɜǂĢɍêĞȧŮǉɍ¡ɞȺɤƇɓȧƪȻɂuÃɤƬɑĖ¤ñȧÍöĀĸƽæɍƥĭñɌɅȮɇļƄȽɠȨʓʟɿʦʩvʪɍ9ĥČɤŌɌøŽȽɠȨǡǤ

3. Selection of touchdown site candidates
Procedure of the selection of landing site candidates
Step 1:Safety score analyses

Box-A, Box-C, Mid-altȦ

Box-A: alt. 20km
Box-Cʶalt. 6km
Medium altitudeʶ
alt. 5km

! Rotation model! Shape model

Step 2:Visual evaluation! Optical images

Step 3:Feasibility analyses! Temperature map! Longitude accessibility! Boulder density

Choose safe landing site based on
attitude of probe, surface
inclination, terrain conditions etc.

From the images from the Optical
Navigation Cameras, investigate
the boulder coverage, presence ofobstacles, surface flatness etc
needed to chose the right place.
Confirm temperature andoperation conditions for the timeof landing. Precisely examine the
distribution of boulders.
ǡǥʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&Ųnĝɍŕɟƚɘʶň1ăǀC©ĥʙʄʟɝɟ(ʩ©đ{ȧĿÁ{ȧJAXAʪʩ©JAXAʪǕ¤ƥĭɈV°ȺɡɂʄʦɾɌsɆȵ©ĥʙʄʟʩZʪɉʞʛɪɲɪ
ŮǉɍǕʩʪ

©ĥʙʄʟɝɟȧ\uÃɌȱȶɠȩ 2¤ɺɴɦȪɤćɚɠȨ
Ȧš¾ȺɡɠǌĴʶ
ȦȦʥ}ƿźʩÍöĀɍ+zƖÞ`ɉ}ƿÞ`ɉȳɋȽźʪȦȦʥŮǉɍ*ȴȦȦʥŮǉɍʄɴʓɴ¤

2¤ɺɴɦɍ
'ɝɟȧɝɟ 2ɋuÃɤƬɑȨǡǦ

3. Selection of touchdown site candidates
Narrow down touchdown candidates: Step 1, from shape modelʩ© U of Aizu, Kobe U., JAXAʪʩ©JAXAʪ

Shape model (right) based on data acquired
during the Medium Altitude Operation, and thedifference in surface elevation on Ryugu (left)

Safety score for each point is calculated by using the shape model.
ȦItems consideredʶȦȦʥSun angleʩangle between +z axis of S/C and the sun)ȦȦʥSlope angleȦȦʥRoughness

The safety scorevalue can aid
selecting a safe
location. ǡǧʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&Ųnĝɍŕɟƚɘʶň1ăǀC©ĥʙʄʟɝɟ(ǎrɎ100m×100mȨ(ʩŜ¤œ¤Ɉ14°×14°ʪ

ʩ©JAXAʪ

2¤ɍǕȮuÃʩ 2¤ɺɴɦɍ'ɍȺȮɉȸɢʪɝɟĸnĝɍ&ŲɉɋɠuÃɤƬɑ

2¤ɺɴɦɍ9Ȩ'ȳȺȮɔɊ 2·ȳǕȮȨěŧɎ'ȳ30ɉɋɠƮ9ȨŜ¤ʩſ[Lʪȳ11ɯÃȧŜ¤ʩſ[Mʪȳ4ɯÃƬ
ɏɡɠ

ǡǨ

3. Selection of touchdown site candidates
Narrow down touchdown candidates: Step 1, from shape model
100m×100m area.
ʩ14Ƞ x 14Ƞ in lat., long.ʪ

ʩ©JAXAʪ

Select candidates for landing sites from locations
with a high degree of safety (low safety value
score).

Safety score distribution.
A smaller value indicatedhigher safety. Gray indicatesregions above a score of 30.

11 low latitude (“L”) and 4
middle latitudes (“M”) wereselected.Ǣǟʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&Ųnĝɍŕɟƚɘʶň2ăǀCĮ+ɝɟ(0ťčɯʘʝɈÕªȺɡɂĮ+ɝɟ&ŲnɤŕɟƚəȨȦďĴĝʶȦȦʥʓʟɿʦʩvʪɍƲȦȦʥó(ɍǂĢɍêĞȜȦȦʥ¡ɞȺ

Ŝ¤ʩſ[Lʪȳ4ɯÃȧŜ¤ʩſ[Mʪȳ3ɯÃɌŕɟƚɗɡɠ
ȜÍöĀȳĸƽȽɠɉȴɌó(ȲɞÎƛȻɇȮȵɍɈȧó(ɌǂĢȳȭɠɉPƾʩ©JAXAȧó{ɋɊʪǢǠ

3. Selection of touchdown site candidates
Narrow down touchdown candidates: Step 2, from images
Choose candidate sites from images
captured with the Optical
Navigation Cameras:ȦFeatures to noteʶȦȦʥBoulder coverageȦȦʥObstacles on the east sideȜ
ȦȦʥflatness

Narrow down to four low
latitude (“L”) and three midlatitude (“M”) sites.ȜSince the spacecraft will approach from the east
when landing, obstacles on the east side are
dangerous.

ʩ©JAXAȧU. Tokyo et al.ʪǢǡʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&Ųnĝɍŕɟƚɘʶň2ăǀCĮ+ɝɟ(ŕɟƚɗɡɂ&ŲʶŜ¤ʩſ[Lʪȳ4ɯÃȧ Ŝ¤ʩſ[Mʪȳ3ɯÃʩ©JAXAȧó{ɋɊʪǢǢ

3. Selection of touchdown site candidates
Narrow down touchdown candidates: Step 2, from images
Candidate sites: four low latitude (“L”) and three mid-latitude (“M”)

ʩ©JAXAȧU. Tokyo et al.ʪǢǣʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&Ųnĝɍŕɟƚɘʶň3ăǀCĨ·ɝɟ(ŕɟƚɗɡɂ7&ŲʩŜ¤4ɯÃȧ Ŝ¤3ɯÃʪȲɞɍçɋɠŕɟƚɘŮǉĖ¤ɍļƄʶŖĖ¤Ɉ370K

7&ŲnĝȽɓɇɈOK

ŮǉÎƛɍœ¤!·ʶnƞƒɉɍơ$ȳƠŖȰɋȮȸɉ
7&ŲnĝȽɓɇɈOK
ʓʟɿʦʩvʪ¤ʶʓʟɿʦɎɋȮÞȳ~ɗȻȮŮǉɍĖ¤9k

7&ŲnĝɤĄƗʩ©JAXAȧƐ>{ɋɊʪ

ǢǤ

3. Selection of touchdown site candidates
Narrow down touchdown candidates: Step 3, feasibility
Further narrowing down from 7 candidates (4 low latitude, 3 mid-latitude)
Surface temperature:absolute temperatureof 370 K or less.

7 candidate points all OK

Longitude dependence of surface
approach: communication withground tracking stations uninterrupted

7 candidate points all OK
Boulder number density:less boulders are preferred
Compare the 7 possible sites

Surface temperature distribution mapʩ©JAXAȧAshikaga U et al. ʪǢǥʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&Ųnĝɍŕɟƚɘʶň3ăǀCĨ·ɝɟ(ŕɟƚɗɡɂ7&ŲʩŜ¤4ɯÃȧ Ŝ¤3ɯÃʪȲɞɍçɋɠŕɟƚɘʓʟɿʦʩvʪʕʁʏɤ¿ȻʓʟɿʦɌɝɠůŶħɤƇɓɠʩ©JAXAȧó{ɋɊʪʓʟɿʦ(vʪʕʁʏɍ

ǢǦ

3. Selection of touchdown site candidates
Narrow down touchdown candidates: Step 3, feasibility
Further narrowing down from 7 candidates (4 low latitude, 3 mid-latitude)
Create boulder map and check boulder coverage

ʩ©JAXAȧU. Tokyo et alʪ

Example boulder mapǢǧʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&Ųnĝɍŕɟƚɘʶň3ăǀCĨ·ɝɟ(ŕɟƚɗɡɂ7&ŲʩŜ¤4ɯÃȧ Ŝ¤3ɯÃʪȲɞɍçɋɠŕɟƚɘʓʟɿʦʩvʪʕʁʏɤ¿ȽɠȨ
L05

L07

L08

M01

M03

M04

L12

ʓʟɿʦ(vʪɍ9Ȩĵ­ȳ3mɍʓʟ
ɿʦɌɅȮɇŧ=Ɉ{ȴȺɤľȽȨ10m
ɍɛɍɎŨŧȨʩ©JAXAʪǢǨ

3. Selection of touchdown site candidates
Narrow down touchdown candidates: Step 3, feasibility
Further narrowing down from 7 candidates (4 low latitude, 3 mid-latitude)
Creating boulder maps
L05

L07

L08

M01

M03

M04

L12

Distribution of boulders.
The size of boulders with adiameter greater than 3m
is indicated by marker sizeand color. Brown is forboulders larger than 10m.
ʩ©JAXAʪǣǟʰʬɾʁʀɿɪʣ&ŲnĝƬɾʁʀɿɪʣ&Ųnĝɍŕɟƚɘʶň3ăǀCĨ·ɝɟ(ŕɟƚɗɡɂ7&ŲʩŜ¤4ɯÃȧ Ŝ¤3ɯÃʪȲɞɍçɋɠŕɟƚɘʓʟɿʦʩvʪɌɝɠůŶħɤƇɓɠ

Ŝ¤

Ŝ¤
Ŝ¤ɈɎȧL08ȧL07 ɍǍȨŜ¤ɈɎȧM04ȨĸnɍȻɜȽȺȲɞɎŜ¤ɍÞȳëɗȻȮɾʁʀɿɪʣ&ŲnĝɎL08ʩʉʁɱɦʁʏʶL07ȧM04ʪȜɾʁʀɿɪʣɍBɌūȯʞʈʦɶʟʮɍŔõɌsɆȮɇȧĸƽĴþ
ĝɤļȺȾɠ
ʩ©JAXAʪǣǠ

3. Selection of touchdown site candidates
Narrow down touchdown candidates: Step 3, feasibility
Further narrowing down from 7 candidates (4 low latitude, 3 mid-latitude)
Determining boulder coverage

Low latitudeMid- latitudeAt low latitudes, L08, L07 inorder. At mid-latitudes, M04Lower latitudes are
preferable for ease of
landingTouchdown candidate point is
L08 (backup: L07, M04)

ʩ©JAXAʪȜTouch down point will be fixedby considering the results of thefirst rehearsal operation that will bedone before the touchdown.

ǣǡʱʬɾʁʀɿɪʣ&ŲnĝɌɅȮɇɍŀĳøŽ
ʞʛɪɲɪɍģ³(
K ɴʕʩĦúʪqȧ5©ɍƎƧ©ĥ
K M­ǩǘ¡oǘŎǣǤǟǘȉȦȦȦȦȦȦʩƎƧM­ǘŎǤǟǟǘȉȧùM­ŎǣǣǟǘȉʪK ƍƲʶŎǣǝǤ,ʅʣʩ#&ŎǢǟǘȉǢȎǜǡʪȜ
K ŤƕƖɍ`ȴǩǘǙȗǛǘȖǚǘǪǘǙǠǧǟǘǗǛǘǜǧǦǘǗǚǘK ƎƧ*ÛźʶŎǧȕ
K Ťƕcìʶ)ǘǪǘǦǝǥǢæƷK TħiʩȑǜǿǾȊȁʪʶǟǝǟǡʩ©JAXAȧó{ɋɊʪK ɱʠʦɾʦɍÙ¤ʶɨʅɯʢɜɬʡɺɉ^ŉ
K yÙɍʓʟɿʦʩvʪɍmǩè{ɍɛɍɎNùƛɌmʩŎǠǢǟȉʪK YŸ0Ɍȱȶɠɺʑɱʅʟǩǘ¡pȧƎƧƛɜùƛɈǇɄɖȮK ƛƎxɌȱȶɠɺʑɱʅʟǩǘ¡pɋǘǙȻƎɘȳȲɄɇȮɠǚǘɺʑɱʅʟȧĆɌɝɠ¦ȮbUȭɟǘK ƙ¤Ė¤ʶ§ȮȍȋȐȄȅȊȂȎȎEõȭɟǙåƷɌȱȶɠĖ¤wIȳȺȮǚȧƎƧƛɈġ½·ȳɝɟ{ȴȮʩȜƎƧɈɍưCɎnĩɍŎ89ɍʮȧɨʅɯʢɍÙ%ɍưCɉɋɠʪ

ǣǢ

4. Science discussions for touchdown
site candidates
Features of Ryugu
K Top shape with a very circular equatorial bulge
K Radius: mean 450 mȦȦȦȦȦȦʩequatorial 500 mȧpolar 440 mʪ
K Mass: 450 million tonʩGM30 m3s-2 )Ȝ
K Rotation axis: (λ, β) = (180ǘǗ, -87ǘǗ)K Obliquity: 8°
K Rotation periodʶP = 7.63 hours
K Reflectance factor ʩv-bandʪʶ0.02

ʩ©JAXAȧUniversity of

K Crater number density: as much as those on Itokawa and Eros Tokyo & collaboratorsʪ
K Many boulders: the largest near the south pole is ~130 m across
K Optical spectra: flat spectra, bluer in equatorial bulge and poles
K NIR spectra: uniform flat (slightly redder) spectra with weak water absorption
K brightness temperatureʶstrong roughness effect (flat diurnal Temperature
variation), higher thermal inertia in the equatorial bulgeʩȜThe gravity at the equator is eighty-thousandth of the Earth and a few times of
Itokawa)

ǣǣʱʬɾʁʀɿɪʣ&ŲnĝɌɅȮɇɍŀĳøŽ
ĸnĝ&ŲɌɅȮɇɍŀĳƁ"ɍʔɨʣʅ(ȣʔɨʣʅʮʶŮǉĢƍʥ ƷƎxɯʘʝɍʄʦɾɝɟŮǉĖ¤ɉġĢĪģ·ɤƇɓɠȨʥƛƎx90żɌɝɠɺʑɱʅʟʄʦɾɝɟȧĢƍɍıɤƇɓɠȨ
ʥ0ťčɯʘʝɍĎƵ=ɍĮ+ɝɟȧn©ʥnƍɜǒIɤƇɓɠȨȦȦȟȜɶɨɬʣɺɉȻɇ¿õȳì®ɈȴɠȲɊȯȲɤƁ"Ƚɠȣʔɨʣʅʯʶ 2·ʥʓʟɿʦɍɶɨɻ9ʥńƷ9ɤƇɓɠʩĮ+ɜʠʦɷǕ¤żʄʦɾɝɟʪ
ȦȦȟȜʓʟɿʦɍɶɨɻǐ¤9ŉȲɞȺȮʓʟɿʦÙɛÏȻ 2·ɤƁ"ȣʔɨʣʅʰʶɶʣʏʟɍUƲʥ ƷƎxɯʘʝɍŹėʄʦɾɝɟŮǉŋ­ɤÏȽɠȦȦȟȜŮǉɌȭɠʠɵʞɺɍŋ­ȲɞȧɝɟyȵɶʣʏʟȳÌVȺɡɠuÃɤƁ"ǣǤ

4. Science discussions for touchdown
site candidates
Scientific evaluation points of landing site candidates■ Point 1: surface properties
ʥExamine surface temperature and thermophysical properties using the Thermal Infrared
Imager data.
ʥExamine composition differences using spectral data from the Near Infrared Spectrometer.
ʥExamine terrain, geology and space weathering from different wavelength images from the
Optical Navigation Camera.
ȦȦ↓Ȝ Evaluate potential scientific merit.
■ Point 2: safety
ʥExamine size and spatial distribution of boulders (from images and laser altimeter data). ȦȦ↓Ȝ Evaluate safety by estimating the number of small boulders from the boulder size
distribution.
■ Point 3: sample yieldʥEstimate surface grain sizes from observational data from the Thermal Infrared Imager.
ȦȦ↓Ȝ From the particle size of surface regolith, evaluate where the maximum amount of sample
can be gathered. ǣǥʱʬɾʁʀɿɪʣ&ŲnĝɌɅȮɇɍŀĳøŽ
ĸnĝ&ŲɌɅȮɇɍŀĳƁ"ɍʔɨʣʅʩʄʦɾɍʪ(

ONC-T ɌɝɠɺʑɱʅʟHƯʕʁʏ (Box-C)

ʩ©JAXAȧó{ɋɊʪǣǦ

4. Science discussions for touchdown
site candidates
The points for scientific evaluation of the landing site candidates:
one example from observation data.

ONC-T spectral slope map (Box-C)
ʩ©JAXA, University of Tokyo & collaboratorsʪǣǧʱʬɾʁʀɿɪʣ&ŲnĝɌɅȮɇɍŀĳøŽ
ĸnĝ&ŲɌɅȮɇɍŀĳƁ"ɍɗɉɚ(&Ųnʔɨʣʅʮ(
ŮǉĢƍʔɨʣʅʯ(
2·

L5(
L7(
L8(
L12(

22(
22(
22(
22

29(
31(
31(
31

12(
12(
12(
11

63(
65(
65(
64

M1(
M3(
M4(

21(
21(
21

33(
30(
33

13(
13(
13

67(
64(
67

ŮǉĖ¤ȧYŸʥƛƎxśɍɺʑɱʅʟɋɊɌȱȮɇȧŮǉ
{ȴɋƩȮɎɋȵȧɔɕýɈȭɠȨɂɃȻȧ²ɋƩȮɎȭɟȧɺʑɱʅʟģ·ȲɞɎȧŜ¤ɍÞȳȧɝɟyýɋŋɤaɥɈȮɠȸɉȳì®ȺɡɠȨǘʔɨʣʅʰ(]ż
ɶʣʏʟUƲƁ"Ɍ{ȴɋɎɋ
ȮȳȧŜ¤(L)ɋɞɏ
L08ȧL07ȳɝȮȨ Ŝ¤(M)ɋɞɏȧM1ȧM
4ȳɝȮȨŜ¤(M)ɍÞȳɝɟȺȮɶɨɻɍŋȳyȮɉ¶ɣɡȧɶʣʏʟɍUƲȳɝɟyȵɋɠɉì®ȺɡɠȨļƄȺɡɂʓʟɿʦʩvʪɍƲɜÏȺɡɂɝɟȺȮʓʟɿʦɍƲȧȺɞɌŮǉɍroughnessɋɊɍ¸tȲɞ 2·ɤƁ"ȨǣǨ

4. Science discussions for touchdown
site candidates
Summary of the scientific evaluation of landing point candidatessite

surface properties

Point 1

Point 2
safety

L5
L7
L8
L12

22
22
22
22

29
31
31
31

12
12
12
11

63
65
65
64

M1
M3
M4

21
21
21

33
30
33

13
13
13

67
64
67

Candidate

Surface temperature, visible / nearinfrared spectrum etc. There is no
big differences across the surface,which is almost uniform. However,there are minor differences.
Spectral characteristics indicatethat lower latitudes may containmore diverse particles.

Point 3
Total
Sample yield
Although no big
difference inevaluation, L08 & L07
are good for low
latitude (L). M1 & M4
are good if mid-latitude(M) is preferred.

Mid-latitudes (M) seem to have many smaller
sized particles, which is expected to increase thesample yield.
Safety is evaluated from information such as
number density of boulders, estimated number ofsmaller boulders and surface roughness.
Ǥǟʱʬɾʁʀɿɪʣ&ŲnĝɌɅȮɇɍŀĳøŽ
ĸnĝ&ŲɌɅȮɇɍŀĳƁ"ɍɗɉɚ((ŀĳɌưŵɋĝʶ(
ʩ1ʪǘʞʛɪɲɪŮǉĢƍɍĕ]ĄɍuÃɌɝɠıɎȺȮȨ(ʩ2ʪǘʞʛɪɲɪŮǉɌɎȧyý·ɤÉɄɂıɋɠĢƍȳĕȼɄɂĥ¼ɈmȻɇȮɠȨ(ʩ3ʪǘɊȸȲɞɶʣʏʟɤÌVȻɇɛȧʞʛɪɲɪ2ɤŮȽɠyý·ɍȭɠƌÚȳÌVɈȴɠYţ·ȳǕȮȨ(ǤǠ

4. Science discussions for touchdown
site candidates
Summary of the scientific evaluation of landing point candidates
Scientifically important points:
ʩ1ʪ Difference in mixing ratio of Ryugu surface material has a low
dependence on location.
ʩ2ʪ A diversity of different materials are present mixed together on
Ryugu’s surface.
ʩ3ʪ Regardless of where the sample is collected, there is a highpossibility of gathering diversified materials that represent thewhole of Ryugu.

ǤǡʲʬǵǫǹǭǷǺɍĸn&ŲnĝƬǵǫǹǭǷǺǘǙǵȋǿȆȈȂǘǫȎȏȂȍȋȆȁǘǹȐȍȃǾȀȂǘǹȀȋȐȏǘǚK ǮǴǸǘ ʩʆɨʂťńɼʣɾʦʪɉǘ ǭǶǯǹʩʍʝʣɺlņĻŃɼʣɾʦʪɌɝɄɇų
K ŎǠǟȇȄɍqɍĸƽĀ
K ʱɅɍŀĀfɤÔƘK Ǡ¤ɃȶɹʚʣʏȻɇŁFYţʩ©JAXAʪǵǫǹǭǷǺÔƘŀĀfǘ
機器名

機能

広角カメラ (MASCAM)

複数波長での画像の撮影

分光顕微鏡 (MicrOmega)

鉱物組成・特性の調査

熱放射計 (MARA)

表面温度の測定

磁力計 (MASMAG)

磁場の測定

ʍʝɨʅʙʄʟ (©(DLR)(

MASCOTǤǢ

5. Selection of landing site candidates
for MASCOTMASCOT (Mobile Asteroid Surface Scout )K Created by DLR (German Aerospace Center)and CNES (French National Centre for SpaceStudies)
K Small lander with mass approx. 10 kg
K Carries four scientific instruments
K Can move only once, by jumpingʩ©JAXAʪ

Scientific instruments aboard MASCOT
DeviceFunction

Wide-angle camera(MASCAM)

Imaging at multiple wavelengths

Spectroscopic microscope(MicrOmega)

Investigation of mineralcomposition and characteristics

Thermal radiometer (MARA)

Surface temperature measurements

Magnetometer (MASMAG)

Magnetic field measurements

Flight model (©(DLR)(

MASCOTǤǣʲʬǵǫǹǭǷǺɍĸn&ŲnĝƬ
MASCOTɍĸnĝƬɍñ(K ɾʁʀɿɪʣ&ŲnɍxɌĸnȽɠʩļħ95ʨʪ
K ¹äɍŤƕcìɍ40ʨɍìƷɌȱȮɇȧơ$Ɉȴɠļħȳ
90ʨɉɋɠ
K }ƿɍ0ȳ¨ɂɠìƷȳ40ʨ70ʨɉɋɠļħȳ90ʨɉɋɠ
K ʉɦʁɱɦʁʏɍ&ŲnȳJMĩȱɝɐNMĩɌmȽɠ
K MINERVA-IIɍĸn&ŲnĝɉưɋɞɋȮ

10,000h100,000hɍʙʣʃɯʟʡʥɸʖʛʠʦɸʜʣɈøŽȺɞɌš¾Ƚɠĝ

10ɯÃƬ

6ɯÃɌŕɟƚɘȧǍȶʥĖ¤ɌƸȽɠñʩàğȧGȧ9ǅBɍâĖȧ¹äŮǉĖ¤ȧzɌȱȶɠMASCOTĵɍĖ¤ʪʥƥĭɍñ
ʥʓʟɿʦʩvʪɍñʥʱɅɍĀfɍŹėñǤǤ

5. Selection of landing site candidates
for MASCOT
Criteria for the selection of landing site candidates for MASCOTK Probability to land outside the candidates for touchdown > 95 %K Probability to have RF link during at least 40% of the asteroid period > 90 %K Probability to have a good daylight ratio (between 40% and 70%) > 90 %K Selection among remaining candidates to have one candidate per reachable
and suitable zone, in northern as well as in southern hemisphere
K No overlap with the landing site candidates for MINERVA-II

computed 10,000  100,000 Monte-Carlo trials
Further conditions

10 candidates

6 candidates & prioritization

ʥTemperature (illumination, orientation, heating,prior separation, asteroid surface temperature,night temperature underneath MASCOT)ʥOperation
ʥBouldersʥObservation conditions for four instrumentsǤǥʲʬǵǫǹǭǷǺɍĸn&ŲnĝƬ(ĸnĝɌɅȮɇɍŀĳɋ<ÜsęĀfĸnĝɌɅȮɇɍ<Üsę

MicrOmegaʩ90Ǒ²ƴʪǭʩĜŏʪɜǷǱʩʋʆʡɰɸsʪɤyȵaəĢƍȳȭɠǕȮǹǶǸʩ$[ǄǊĄʪɤ°ɠɂɚɌĸnĝɍĖ¤ȳȮµŵȭɟ

MASCAMʩ£źɯʘʝʪ

ŸƱɌɎȮɠʓʟɾȘʩvʪ²ŋıɋɠĢƍȳĕȼɄɇȮɠȸɉʩɺʑɱʅʟʧʪ
ÝǖɋĢƍʩǒIɤWȶɇȮɋȮʪ

MARAʩġ×żʪ

ʠɵʞɺȳŪȮȲĞȮ
ʓʟɿʦʩvʪɍƛȵɌĸnȽɠȸɉȳ~ɗȻȮġĳɌw·ȻɇȮɋȮuÃɤ-/

MASMAGʩĽCżʪőȲȮŋɍʠɵʞɺɈġ½·ȳȮġ½·ȳýʩǵǫǸǫɜǺǲǸɍʄʦɾɉɍƸƣʪĺɍƲȳɋȮȞŸƱ4Ɍo·ȳɋȮȩɎɜɑȺʯȪɌÔƘȺɡɂʞʙʦʅɼʣɸʣɲĀfɌɝɠʞʛɪɲɪɍ
;ìŹėŔõ : Ůǉ2ɌɣɂɄɇ{ȴɋwIɎɋȮȞýɈȭɠǤǦ

5. Selection of landing site candidates
for MASCOT
Scientific Criteria for Landing SiteInstrument

Criteria for Landing Site

MicrOmega

Composition of C-rich and/or OH-rich content.
Low Temperature of landing site for high SNR (signal-to-noise ratio).

MASCAM

Boulders in the field of view
Fine grained particles
Compositional heterogeneity (color!)
Fresh material (non-weathered)

MARA

Thin to no regolith layer.
Landing or hopping close to boulders preferable.
Preferentially less thermally altered region.

MASMAG

Low thermal inertia for fine grained fraction of the regolith
Homogeneous thermal inertia (link the MARA + TIR data)
Low rock abundance -> no inhomogeneities in the FoV (field of view)
Remote sensing instruments onboard HY2 give preliminary information on
Ryugu : no big variation over the surface " homogenousǤǧʲʬǵǫǹǭǷǺɍĸn&ŲnĝƬ
MASCOTɍĸnĝ&Ųʶ10ɯÃƬʩMAC1MAC10ʪ(ʩ©DLR,CNESʪĆŧȳè;ɌÎnȽɠǎrɈȧǇȮǎrȳǈĂȽɠǎrȨɾʁʀɿɪʣ
&ŲnĝȳƎʩŜ¤ʪȱɝɐʌʣɱʩ Ŝ¤ʪɍgźɈľȺɡɇȮɠȨǤǨ

5. Selection of landing site candidates
for MASCOT
Landing site candidates for MASCOTʶʶ selected 10
candidates (MA-1
MA-10)(ʩ©DLR,CNESʪ

Light blue shows the first contact points and blue shows the first settlement
points. The candidates of touchdown sites are shown by red squares (lowlatitude) and pink squares (mid- latitude).ǥǟʲʬǵǫǹǭǷǺɍĸn&ŲnĝƬ
MASCOT ĸn&ŲnĝǍȶƊǘ(ʅɩʦʟʦɻǘ8é14à)

ʩ© CNES/Rémi Benoît, 2018)īĬĳɋ]Ȩʞʈʦɶʟɜžŝȳ«ɌņɄɂʩJAXAɌ»ƉȽɠʪ=> ƦłɎŴǄɃɄɂȳȧȽɓɇɍǌĴɌɅȮɇɺɳɹʛʦʟɌċɄɇūȯȸɉȳɈȴɂȨǥǠ

5. Selection of landing site candidates
for MASCOTMASCOT Ranking meeting (Toulouse Aug 14)

ʩ© CNES/Rémi Benoît, 2018)

Fruitful meeting, useful rehearsal and training (thanks to JAXA)=> complex process but all milestones/deliveries were reachedaccording to the scheduleǥǡʲʬǵǫǹǭǷǺɍĸn&ŲnĝƬ
MASCOTɍĸnĝ&Ųʶ10ɯÃȲɞɍŕɟƚɘɉ-/Ǎȶ(ʩ©DLR,CNESʪ

ĸnĝ&Ųɍ-/ǍʶMA-9 > MA-1 > MA-10 > MA-7 > MA-5 > MA-2
ǥǢ

5. Selection of landing site candidates
for MASCOT
Landing site candidates for MASCOTʶʶSelection from
10 candidates and the order of priority

ʩ©DLR,CNESʪ

Priority of landing siteʶMA-9 > MA-1 > MA-10 > MA-7 > MA-5 > MA-2ǥǣʲʬǵǫǹǭǷǺɍĸn&ŲnĝƬ
MASCOTĸ
ĸƽ&Ųnĝ©JAXA, ó{, ǕĹ{, ņØ{, _X{, Kũ{, ãĊ{, đ{, ĬřĻǘ, CNES, DLRǥǤ

5. Selection of landing site candidates
for MASCOTMASCOT landing site©JAXA, University Tokyo, Kochi University, Rikkyo University, Nagoya University,
Chiba Institute of Technology, Meiji University, University of Aizu, AIST, CNES, DLRǥǥʳʬǵǲǶǯǸǻǫǜǲǲɍĸn&ŲnĝƬ
MINERVACIIC1ɍAɉBɤ9ǅȽɠʩMINERVACIIC2Ɏò¢Ɍ9ǅ ʪ((
MINERVA-II-1A, 1BJAXAųMINERVA-II-1AȧMINERVA-II-1Bɍý

MINERVA-II-2

ʥɶɨɻʶĵ­17cmȧǕȺ7cm
ʥƍƲʶɀɡɁɡŎʮkgʥɦɱʀʛɬʦɾʶʯɅɍDCʙʦɾʥÔƘɼʣɶʶɯʘʝȧʍɭʅɿɨɮʦʆȧDƢæżȧĖ¤żȧɹʚɨʡʥơ$Ƣ¤ʶ32kbpsʩè{ʪMINERVA-IIɴʣɽʦɸɦʗʩóJ{ʫóǆĀ{ʫ{ƹ{ʫ©{ʫóĪŀ{ʪȳųǥǦʩ©JAXAʪ6. Selection of landing site candidates
for MINERVA-II
Release of MINERVA-II-1 A & BʩMINERVA-II-2 will be released next yearʪ

(

MINERVA-II-1A, 1B

Produced
at JAXAMINERVA-II-1AȧMINERVA-II-1B
Specification

MINERVA-II-2
Created by the MINERVA-II
consortium (Tohoku
University, Tokyo Denki
University, Osaka
University, Yamagata
University, Tokyo
University of Science)

ʩ©JAXAʪʥsizeʶdiameter 17cmȧheight 7cm
ʥweightʶabout ʮkg each
ʥActuatorʶ2 DC motors
ʥMounted sensorʶcamera, photodiode,accelerometerȧthermometer, gyro.
ʥCommunication speedʶ32kbpsʩmaxʪǥǧʳʬǵǲǶǯǸǻǫǜǲǲɍĸn&ŲnĝƬ
MINERVACIIɍĸnĝƬɍñʶ(ʥĸnȽɠuÃȳɾʁʀɿɪʣ nɉưɋɞɋȮȸɉ(ʥĸnȽɠuÃȳMASCOTɍĸn nɉưɋɞɋȮȸɉ(ʥ9ǅ¯ɍÍöĀǕ¤ȳ30mɝɟȵɋɞɋȮȸɉ(ʥnɉɍơ$ȳļ#Ɉȴɠȸɉ(ʥĖ¤ȳǕȵɋȮǎrɈȧƼɉɋɠǎrȳɋȮȸɉ(ʥƎƧƛɎʞʁɹʩ÷ʪɉɋɄɇȮɠɂɚȧƎƧƛɌ9ǅȽɠɉĸnĝȳNJɌ{ȴȵ£ȳɄɇȻɗȯȨ(ĸnşʥNMĩɌ9ǅȻɂu]ȧÍöĀǕ¤ȳ( JMĩ
Ȧ30mɝɟȵɋɠYţ·ȳȭɠȨ(
9ǅş

NMĩ

ʥƎƧȲɞJMĩ(Ɍ100m
ǅɡɂɉȸɢɌ9ǅȽɠ(ʩ©JAXAʪƎƧƛɌ9ǅȽɠɉȧĸnşȳNJɌ£ȳɄɇȻɗȯǥǨ

6. Selection of landing site candidates
for MINERVA-II
Conditions for MINERVA-II landing site selectionʶʥ Landing site does not overlap with spacecraft touchdown candidates.
ʥ Landing site does not overlap with MASCOT landing site candidates.
ʥ The altitude of the spacecraft after separation must not be lower than 30m.
ʥ Ensure communication with ground station.
ʥ Not high temperature region, and fewer parts in shadow
ʥDue to the equatorial ridge, separation near the equator results in widely spaced
landing points to the north and south.
ʥSeparating in the southern hemisphere may result
Landingin a spacecraft altitude below 30m.
north
locationsouth

ʥSeparate in northern hemisphere,
more than 100m north of the equator.

Separation
position

ʩ©JAXAʪ When separating near the equator, thelanding position spread north and south.ǦǟʳʬǵǲǶǯǸǻǫǜǲǲɍĸn&ŲnĝƬ
MINERVACIIɍĸnĝ&ŲʶJMĩɈøŽ(Ŝ¤Ɍȱȶɠ
ɾʁʀɿɪʣɍ
Yţ·ȭɟ

nɉɍ
ơ$ñYœ¤0°
ʩ©JAXAʪʥɾʁʀɿɪʣʥMASCOTɍĸnĝɉưɋɞɋȮȸɉɤļƄ
ʥONC-TɌɝɠŹėYţ·ŉɛš¾&ŲnʶN6 > N1 > N7
ǦǠ

6. Selection of landing site candidates
for MINERVA-II
Landing site candidates for MINERVA-II: northern hemisphere

Possible overlap
with mid-latitude
touchdown

No communication
with ground station
Longitude 0°
ʩ©JAXAʪʥTouchdownʥconfirm no overlap with
MASCOT's landing site.
ʥAlso consider observability etc. using the
ONC-T camera.

Candidate locationsʶ
N6 > N1 > N7 ǦǡʴʬĸƽĨɌ`ȶɂÀİȸɍăǀɈĸƽȳ¿ņȽ
ɠ&ŲȳƬɏɡɇȮɠȥ¨;żĮ
ȫ&ŲĝÍŐȡȬ(ȫŕɟƚɘȡȬ(ȫĸƽƥĭȡȬ(ÆŬĳɌĸƽYţɋɬʞɦɤŴÙÇ8

ŀĳɌ"'ɍǕȮɬʞɦɤ-/ǍɤɅȶɇ2ʺ3Ƭ8-/ǍɍǕȮ&ŲĝɌȻʞʈʦɶʟƺʫĸƽɤß

ȫ&ŲĝÍŐȢȬȫŕɟƚɘȢȬȫĸƽƥĭȢȬʥʥʥĸƽɍhÙɃȶŞɟƜȽȥÝżĮȸɍăǀɈĸƽ¿ņ·ɍȺɞɋɠŌöȳµŵȫ&ŲĝÍŐȬ(ĶĳɌ 2ɀȯɋɬʞɦɤŴÙÇ8ȫ¸tUǃȬ(ȫŕɟƚɘȬ(ŀĳɌ"'ɍǕȮɬʞɦɤ1ʺ3Ƭ8ĸƽʞʈʥĸƽĀƥĭɤơȼɇʫǕ¤ɍ¸tɉƺƅŌ¤ɤUǃȽɠȫĸƽ(Ƃū)ƥĭȬ(ĸƽɤƂūȽɠʬu]ɌɝɄɇƠ Ɉ ĂȻʫĸƽɬʞɦɍ9ôɌ«ņɇɠƥĭŠĠĸƽĝƬ(LSS)ƊɌɇß

ǕŻ+¤
nŮĮ+

ĥČɌɝɄɇɎʫƥĭĹŷɤƓɗȰɇĸƽĝƬȲɞ6ßȽɠ

ĸƽĀƥ
ĭʄʦɾ

ĸƽÆŬɍĐŝIʫɸʦɳʣɺÖŦɤȻɋȳɞŞ
ɟƜȽʬ

ǦǢ

7. Strategy toward the successful touchdown
Landing(site(candidates(
selected(at(this(stage.ȥ Initial planȫCandidate site searchȡȬ

ȫReﬁne(ȡȬ(ȫLanding(opera-on(ȡȬ(Iden-fy(mul-ple(technically(
landable(areasSelect(2(C(3(sites(by(ranking(areas(of(scien-ﬁcally(high(value

Perform(rehearsal(descent(&(landing(for(high(priority(candidate(sites(ȫCandidate site searchȢȬ


ȫReﬁne(ȢȬȫLanding(opera-on(ȢȬʥʥʥFurther(examina-on(of(landing(feasibility(necessary(at(this(stage.

ȥNew planȫCandidate site searchȬ

Iden-fy(mul-ple(rela-vely(safe(areas

Depending(on(situa-on,(reimplement(from(landing(site(selec-on(based(on(opera-onal(knowledge

Repeat for each landingȫReﬁneȬ(Select(1(–(3(sites(with(high(scien-ﬁc(merit(Landing Site Selection(LSS). Conducted atconference.

Operational
proficiencyȫGather informationȬ

b

By landing rehearsals & landing
gear operations, collect low altitude
and descent guidance information.

High resolution
surface images
Landing gear
operational dataȫLanding (trial) operationȬ

Landing attempt. Depending on
circumstances, stop half-way anduse data to analyze landing area. 

Repeat(while(reﬁning(landing(technique(and(improving(this(sequence.

ǦǣʴʬĸƽĨɌ`ȶɂÀİưŵɋ ǌǕ¤ȲɞŮǉɤƃȻȵƇɓɠťčƅŌ¤ɤɊȸɗɈȷɠȸ
ɉȳɈȴɠȲʩ©JAXAȧó{ɋɊʪǕ¤Ŏ1kmȲɞÕªȻɂʞʛɪɲɪŮǉǦǤ

7. Strategy toward the successful touchdown
Important point
Detail of surface from low altitudeHow far can thenavigation
guidance accuracy
be increased?

ʩ©JAXAȧó{ɋɊʪRyugu surface taken from an altitude of about 1km.Ǧǥʵʬ¯ɍ ȣſŢƆãɍ 
K 9é((5àʩĆʪ11:00ʺ12:00(
K 9é27àʩíʪ14:30ʺ15:30
ȣɦɪʅʞʦʀʥɨʐʣʅ#  `ȶɨʐʣʅ
K șɋȿɋɌȩɎɜɑȺʯȪɈɛƍeØȚ
K ǨéǡàʩàʪǠǣæǠǥæ
K ĶÿQņOĢǓK ʇʁʅ ŗŉɛūȯ ʩæAɎàïæƷʪǦǦ

8. Future Plans■Schedule for press briefings
K Sept. 5 ʩWedʪ11:00ʺ12:00
K Sept. 27 ʩThursʪ14:30ʺ15:30■Outreach and events (in Japanese)# Events for Children
K Why Hayabusa2? Any questions classroom
K Sept. 2 (Sunday) 2 – 4pm
K Sagamihara City Museum
K Online broadcast planned(Time : JST)
Ǧǧ