Asteroid explorer, Hayabusa2
press conferenceDecember 13, 2018
JAXA Hayabusa2 ProjectTopics
In connection with Hayabusa2:
RSolar conjunction operationRMINERVA-II1 roversContents
0. Hayabusa2 and mission flow outline
1. Current status and overall schedule of the project
2. Solar conjunction operation report
3. MINERVA-II1 rovers
4. Other
5. Future plans

Overview 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 solarsystem. 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
RBy 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 ofits oceans and life, thereby developing solar system science.
R 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.
RWe will establish stable technologies for return exploration of solar-system bodies.

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

International positioning^
RJapan is a leader in the field of primitive body exploration, and visiting a type-C
asteroid marks a new accomplishment.
RThis 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.
RNASA 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
MassApprox. 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.

Mission Flow
Launch3 Dec 2014

Arrival at asteroid
June 27, 2018>▲
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

Release impactor

Use an impactor to create
an artificial crater on theasteroid’s surface1. Current project status& schedule overview
Current status^– Solar conjunction operation is underway.
– As of December 13, the altitude from Ryugu is about 108 km and the approach
speed is about 1.3 cm/s.
– From here, we will return to the home position at the end of December.

Schedule overview:
2015
3

12

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2016
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launch	*(2017

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2020
12

Arrival at Ryugu	71* !* *1612
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Earth swing-by	*(&4 &;2019

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6*5623*4&6.215 Southern hemisphere stationoperations (CAN/MLG)	
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Ion engine operations ※	

2018

Departure from Ryugu	28a*(Capsule re-entry	&6*

Optical navigation	 Solar conjunction	
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2. Conjunction Operation Report
F Currently, we are in solar conjunction. The angle of the Sun-Earth-spacecraft isless than 3 degrees and it is difficult to communicate with the spacecraft.
F On 12/29 ΔVTHPR^Home Position RecoveryU is planned to return to the homeposition.
Orbit control
Name

Date

COI

2018/11/23

TCM1

2018/11/30

TCM2

2018/12/25

HPR

2018/12/29

Sun

12/15
12/10

12/5

12/25

12/20

TCM2

TCM1

11/30

COI : Conjunction Orbit Insertion>>>>>
TCM : Trajectory Correction Maneuver>>>>
HPR : Home Position Recovery>>>>>

T©JAXAU

Conjunction transition orbit in the Hill
coordinate system

11/23

COI

Ryugu

HPR

12/29

3. MINERVA-II1
n 9/21 13:06 JST separation from the Hayabusa2 spacecraftn Day 1 (SOL.1UTelemetry received from the rovers
RImage data receivedn Day 2 (SOL.2URover ON confirmed, waiting for telemetryn Day 3 (SOL.3URover ON confirmed, waiting for telemetryn Day 4 (SOL.4URover-1A telemetry received
F Rover-1A hopping confirmed
F Rover-1B telemetry received, preparing to hop
RRRRRRR
TNoteUSOL (solar day). Sun day. This means one sun day usuallyon a celestial body other than the Earth. For example, it is also usedfor the operation of the Mars probes. In the case of Ryugu, 1 sol isabout 7.6 hours.
3. MINERVA-II1
n Day 7 (SOL.7URover-1B telemetry received
F Rover-1B hopping confirmed
F Image data received
RRRRRRRn Day 10 (SOL.10U Rover-1B telemetry received
F Power decline during telemetry transmission
F Thereafter, no further telemetry received
RRRRRRRn Day 27 (Sol.27URover-1A telemetry received
F Stereo image from Rover-1A received
RRRRRRR3. MINERVA-II1
n Day 113 (SOL.113URover-1A telemetry receivedn Day 114 (SOL.114URover-1A
F Telemetry not received
F Thereafter, no further telemetry
RRRRRRRRRRRRRR
During solar conjunction, there is no operation of theMINERVA-II.
3. MINERVA-II1
u Rover-1A^
11/02^During the BOX-C operation, we proceeded to process andsend commands. Rover-1A turned ON and the transmitted command
was received. However, we did not receive telemetry from Rover-1A.
It is estimated that there is a shortage of power, possibly from therover being in shadow.
u Rover-1B
Radio waves were received from Rover-1B several times. However,after the radio waves were received, the rover turned off and we could
not receive any telemetry. This is also thought to be due to a power
shortage due to the rover possibly being in shadow.
As the seasons on Ryugu change, there is a possibility that Rover-1A,
1B may wake up as the sunlit environment changes. We plan toresume operations after solar conjunction.

Images taken by Rover-1A>>
Bfirst public releaseC

Timage credit^JAXAU

Figure 1>SOL.27^ Image taken on September 29, 2018 JST by Rover-1A, captured
with the on-board stereo camera. Proximity image of the asteroid surface.

Images taken by Rover-1A>>
BfirstpublicreleaseC

Figure 2>SOL.76^ Image take on October 14, 2018 JST by Rover-1A with aTimage credit^JAXAU
wide-angle camera during a hop.

Images taken by Rover-1A>>
BfirstpublicreleaseC

Figure 3>SOL.94^ Image taken on October 20, 2018 JST by Rover-1A with therear wide angle camera while stationary on the asteroid surface. TImage credit^JAXAUImages taken by Rover-1A>>
BfirstpublicreleaseC

Figure 4>SOL.94^ Image taken on October 20, 2018 JST by
Rover-1A while stationary with the forward wide-angle camera.

TImage credit^JAXAUImages taken by Rover-1A>
BfirstpublicreleaseC

Figure 5>SOL.97^ Image take on October 21, 2018 JST by
Rover-1A by the wide angle camera during a hop.
TImage credit^JAXAUImages taken by Rover-1A>>
BfirstpublicreleaseC

Figure 6>SOL.112^ Image taken on October 26, 2018 JST by
TImage credit^^JAXAUU
Rover-1A with the wide angle camera while stationary.

Images taken by Rover-1A>>
BfirstpublicreleaseCFigure 7:>SOL.113^ Image taken on October 26, 2018 JST by
Rover-1A with the wide angle camera during a hop. TImage credit^JAXAUImages taken by Rover-1A>>
BfirstpublicreleaseC

Figure 8>SOL.113^ Image taken on October 26, 2018 JST by
Rover-1A with the wide angle camera during a hop. TImage credit^JAXAUMINERVA-II1 Rover landing site
MINERVA-II1 rover landingsite nickname@LOMLJA
TRINITAS
Trinitas is the birthplace ofthe goddess Minerva.
TImage credit: JAXA, University ofTokyo, Kochi University, RikkyoUniversity, Nagoya University, Chiba
Institute of Technology, Meiji
University, Aizu University, AIST)

September 21, 2018 at 13:02 JST
Image with the ONC-W1 at 70m altitudeMINERVA-II1 collaborators
Aichi University of Technology, Nakatani Laboratory (mounted camera lensU
University of AizuTmounted solar cellU
Addnics Tmounted communication equipmentU
Antenna GikenTmounted antennaU
WEL ResearchTzero gravity experimentsU
ElnaT mounted electric double layer capacitorU
Keio University, Ishigami Laboratory Tzero gravity experimentsU
System ConsultantsTFPGA spacecraft I/FU
SECCIA TechnoTOME development, experimental rover, zero gravity experimentsU
Digital SpiceTOME data processing, mounted processing U
Tokyo Institute of Technology Co60 irradiation roomTradiation testU
University of Tokyo, Sugita LaboratoryTcamera calibrationU
Tokyo Denki University, Kurisu LaboratoryTzero gravity experimentsU
Tokyo Denki University, Kobayashi LaboratoryTcommunications testU
Nittoh OpticsTnowVnittoh inc.UTmounted camera lenseU
Maxon Japan Tmounted motorU
Meiji University, School of Science & Engineering, Kuroda Laboratory Tzero gravity
experimentsUn DLRTDrop experimentUn NOVASPACETaircraft experimentUn ZARMTDrop experimentUnnnnnnnnnnnnnnnnnMINERVA-II1 Rover naming
In Roman mythology, Minerva is the goddess of music, poetry,medicine, wisdom, commerce, magic, weaving and crafts. In worksof art, she is also depicted with an owl as her sacred creature andsymbol of wisdom.

Goddess’s bird^Owl (horned owl)

■From the French for horned owl:

Rover-1A^^FNSTHIBOUUU

Highly Intelligent Bouncing Observation Unit
■From the English:

Rover-1B^^EGPTOWLUU

Observation unit with intelligent Wheel Locomotion
MINERVA-II1 Rover namingRover-1ARover-1B

From the French for horned owl From the English

イブーHIBOU

アウルOWL4. Other
■AGU Fall Meeting notes:
F The fall meeting of the AGU TAmerican Geophysical UnionU isbeing held in Washington DC (Period: 10 – 14 December, 2018).
This is a large planetary science academic society based in the USA.
The number of registered participants for this meeting reached
20,000 (announced by organizer).
F In collaboration with OSIRIS-REx , a session was held entitled <A
First Look at 162173 Ryugu and 101955 Bennu: Hayabusa 2 andOSIRIS-REx Arrive at Their Respective Target Asteroids”.
F Session data: December 11 (oral), December 12 (poster)
Hayabusa2	  OSIRIS-­‐Rex	  Both	  Total
F Lecture stats:
topic

topic	  missions

Oral	  presenta�ons

WY\X	  XY	  Posters

WZ]

W	  XZ	  Total

X[W[YZ[4. Other
=AGU Fall Meeting notes:
Main announcements in the oral sessions:>■Related to Hayabusa2RMission explanation (science, spacecraftetc.)
RSummary of observation data so far
RDetails of the surface spectrum
RMASCOT related operations
RDetails of the results from each instrument■Related to OSIRIS-REx
RMission explanation (purpose, spacecraft,schedule, etc)
RLatest observation data (surface
environment, shape, density, spectrum etc.)
RWater absorption measurement
RLarge variations in surface reflectance
RDistribution and shape of craters andbouldersPhotograph from the joint oral session of
Hayabusa2 and OSIRIS-REx on December 11,
2018 (US time). Participants filled the seats in thelarge room.TCredit^JAXAU5. Future Plans■Scheduled operations
F Until the end of December^Solar conjunction
F From January, 2019^Normal operation■Results of the Ryugu Imagination Contest
F Scheduled for late December■Press Briefings and MediaF Tuesday, January 8 afternoon, reporter briefing @Ochanomizu
ReferenceConjunction operation
F “Conjunction” for spacecraft

2018.12.31

operation refers to the case wherethe spacecraft is in the directionthat almost directly overlaps with
the Sun when viewed from Earth.

2018.11.20

Earth

F The alignment means thatcommunication with thespacecraft is not secure due toradiowaves radiated by the Sun.

SunF In this period, critical operation isnot carried out.

F For Hayabusa2, the duration ofthis period is from late November
2018 – end of December.

Ryugu
Positions of Ryugu and the Earth©JAXA



Conjunction operation
Orbit and trajectory control during the operation
Orbit control
Name

Date

COI

2018/11/23

TCM1

2018/11/30

TCM2

2018/12/25

HPR

2018/12/29

Due to the influence from solar tidal forces,
asteroid gravity and solar light pressure, thetrajectory forms a complex shape.

COI : Conjunction Orbit Insertion>>>>>
TCM : Trajectory Correction Maneuver>>>>>
HPR : Home Position Recovery>>>>>

©JAXA

Transition orbit during solar conjunction in thehome position coordinate system

MINERVA-II1 Rovers
MINERVA-II is the successor of MINERVA installed on the Hayabusa spacecraft.	  
MINERVA-II1 (Rover-1A, Rover-1B)

Producedat JAXA
T©JAXAU_ Collaborating manufacturers, universities andrelated organizations`
Aichi University of Technology, University of Aizu,Addnics corp.VAntenna Giken Co., Ltd., ELNA ,CesiaTechnoVThe University of Tokyo, Tokyo
Denki University? Digital Spice Corp., Nittoh Inc.VMaxon Japan, DLR, ZARMl Weight (including deployment)
MIMERVA-II1 :2.5kgl MINERVA-II1Twin rovers 

MINERVA-II1 Rovers
MIcro Nano Experimental Robot Vehicle for Asteroid,
the Second Generation

F New hopping mobility
F Adaptation with AI
F Small, light-weight,
F Low power consumption
F Autonomous behavior

T©JAXAUF Scientific observation（stereo sensing, thermometer) 

MINERVA-II1 Rovers
bodysizeweight
actuators
sensorscom.

Cylinder (hexadecagonal pole)
Diameter: +180[mm]
Height: 70[mm]1A:1151[g], 1B:1129[g]DC motor
4 cameras(1A), 3 cameras(1B)
photodiodes, accelerometer
thermometers, gyro
32k[bps](max) 

MINERVA-II1 Rover landing site (N6)

TDHQIKL^JAXAVU
T©JAXAU