Operation status for the asteroid explorer,
Hayabusa2, in the vicinity of Ryugu	

July 19, 2018!
JAXA Hayabusa2 Project!

Today’s Topics
	

Regarding Hayabusa2:!
• Current status of the mission!
• Science (remote sensing, sample, TIR)!
• Mission schedule!

2	Table of Contents	
０．Hayabusa2 overview: outline of the mission flow.!
１．Current status and overall schedule of the project. !
２．Anticipated scientific achievements!
３．Expectation for the sample analysis!
４．Initial observational results with the mid-infrared
camera (TIR).!
５．Mission schedule!
6．Future plans!

3	Overview of Hayabusa2	
Objective	We 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
・By 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.	
・ 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.
・We will establish stable technologies for return exploration of solar-system bodies.	

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

International positioning：
・Japan is a leader in the field of primitive body exploration, and visiting a type-C
asteroid marks a new accomplishment.
・This 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.
・NASA 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.

4	

(Illustration: Akihiro Ikeshita)	
Hayabusa 2 primary specifications
Mass
Approx. 609 kg
Launch3 Dec 2014
MissionAsteroid return
Arrival2018
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

Releaseimpactor

Use an impactor to create
an artificial crater on theasteroid’s surface5	１. Current status and project schedule	Current status： !
– Since arrival at Ryugu (June 27, 2018), the spacecraft has maintained the Home
Position (BOX-A) at an altitude of 20 km.!
– Remote analysis has continued using the onboard observational instruments(ONC, LIDAR, NIRS3, TIR).!
– This week (July 16-) focused on preparation for the transition from BOX-A to low
altitude (BOX-C), with the descent taking place today. !

Schedule overview： 	
2015	
12	

Event	

3

Initialoperation	

2016	
10 12	EDVEGA	launch	(Dec 3)	

2017	

4	

swing-by	

Mar	
 Jun	

Journey to asteroid	

2020	
12	

Arrival at Ryugu	
(June 27)	12
Re-entry	
Earth return	

Asteroid proximity operations	

Earth swing-by	(Dec 3)	

Mar	
 May	

2019	

6 7	
approach	

ESA（MLG/WLH）
test operations	
 Southern hemisphere station
operations (CAN/MLG)	
(May 21- 22)	
Oct	
May	

Ion engine operations ※	

2018	

Departure from Ryugu	
(Nov～Dec)	

Capsule re-entry	
(Late 2020)	

Optical navigation	
 Solar conjunction	
May	
 Jul	
 Nov	
 Dec	
Nov	

Apr	

Jan	

Jun	

TBD	

TBD	
TBD	

TBD	

6	

２．Anticipated Scientific Achievements	

June 27, 2018

Arrival at Ryugu

7	2.1 Appearance of Ryugu
	・The surface is very dark. The axis of rotation is nearly perpendicular to orbital plane.
・Features include craters, numerous boulders (including rocks up to 130m in size)
and a grooved terrain.	

UTC 2018-06-26 03:50	

8	

2.1 Appearance of Ryugu	(animation）	
Image credit：JAXA, University of Aizu, University of Tokyo, Koichi University, Rikkyo University,
Nagoya University, Chiba Institute of Technology, Meiji University, AIST	

9	

2.2 Shape Model of Ryugu
	The shape model was constructed using two different methods, but they are in good
agreement.	

(animation）	
Shape model by the University of Aizu (SfM)	

Shape model by Kobe University (SPC)	

image credit：University of Aizu, Kobe University (shape models), Auburn University (movie),
JAXA

10	

2.3 Ryugu at zero degrees longitude	
Selecting the position for zero degrees longitude	Credit ：JAXA, University of Tokyo, Koichi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji
University, University of Aizu, AIST.

Selection：
・Early on, Project Members identified a prominent feature: 2 rocks
that were vertically aligned.
・In the image, the lower rock is near the equator and creates asuitable landmark.
Note：The photograph here shows the asteroid’s North Pole at the top (theopposite to the published images)	

Reasons for selection：!
・Good visibility !
・The center is easily seen!
・Notable topology!
・Close to the equator	

11	

2.4 Mt Fuji and Ryugu at 20 km	

(animation）	
Created by Yasuhiro Yokota（JAXA)：（using http://www.city.fuji.shizuoka.jp/page/gazou/fmervo000001dsro.html ）	

12	

2.5 Boulder distribution on the surface of Ryugu	• 300
見かけの大きさが12	
  m以上の岩塊に+マークをつけた	
  degrees longitude	
60 degrees longitude	

credit： Kindai University/JAXA/U. Tokyo/Koichi U./Rikkyo U./Nagoya U./Chiba Inst. Tech/Meiji U/U. Aizu/AIST	

・There are many boulders on the small celestial body: possibly the asteroid consists offragments of the parent asteroid.!
・The number density (number per unit area) varies greatly over the surface.!
・The distribution of boulders is key to deciding the best location for the touchdown points where
the surface samples will be collected.!
・The distribution is also useful for understanding and confirming surface material migration．	

13	

2.6 LIDAR Shape Measurement
	Global topographical data for Ryugu was acquired
from a LIDAR scan on July 11．
(Top) Map showing the distribution of themeasured points. Color indicates the angle
between the laser irradiation and the asteroid
surface (irradiation from directly overhead is zero
degrees). Surface data (to calculate the angle) was
acquired from the shape model.
(Right) Shape of Ryugu measured by the laser
altimeter. It almost coincides with the shapemodel.

Credit: NAOJ/JAXA/Chiba Institute ofTechnology/U. of Aizu/Nihon U./Osaka U.	

14	

2.7 Anticipated scientific achievements
	••

Visible (ONC) ・Near infra-red（NIRS3） reflection spectrum: dark and flat.!
– Characteristics of Ryugu’s reflection spectrum differ from any meteorite. !
– On the other hand, it resembles that of comets and asteroids. !
– Very dark surface: possibility of high abundance of carbonaceous material. !
– While nearly homogenous, there are also regional characteristics, so we await
future precise analysis.
!
Reconstruction of the parent body of Ryugu !
– The big boulders suggest that Ryugu formed by the accumulation of debris
from the destruction of the parent asteroid. !
– Narrow down the Landing Site Selection (LSS) based on observational
results: !
• First of all, the safety and scientific value is evaluated.!
• Details of the potential sample material and understanding of thegeological context.!
– Verification upon sample return, comparison with OSIRIS-Rexe exploration
results. 	

15	

３．Expecta(on	
  for	
  sample	
  analysis
	Hayabusa2 sample：!
!
Scientific analysis requires aminimum sample of 100 mg collectedfrom multiple locations (3 areas) on
the surface of the celestial body,
analyzed promptly with state-of-theart technology in 2020 without
terrestrial contamination.!
1. Surface particles are collected byfiring bullets (make from 5 g oftantalum) inside the sample horn.!

16	３．Expecta(on	
  for	
  sample	
  analysis
	Hayabusa2 sample：!
!
Scientific analysis requires aminimum sample of 100 mg collectedfrom multiple locations (3 areas) on
the surface of the celestial body,
analyzed promptly with state-of-theart technology in 2020 without
terrestrial contamination.!

(アニメーション）	

2. Surface particles are collected byusing the inverted tip of the sampler
horn.	

17	

３．Expecta(on	
  for	
  sample	
  analysis
	Sample catcher：!
!
Stores collected particles. Samples
collected from the three surface
locations are separately stored in thethree-sectioned structure. !
Sample container: !
!
Seal the sample container, store andreturn to Earth. Any gas component
generated from the sample can also
be analyzed. !

18	

３．Expecta(on	
  for	
  sample	
  analysis
	Star-forming
clouds	

Galaxies		Protoplanetarydiscs
	

Asteroids		Earth, life andoceans		Asteroid	
Ryugu’s history	Origin of the Solar System, early evolution
Solar System material	

(c) ESO/S. Brunier	(c) NASA
	(c) NASA
	Delivery of the
Earth’s oceans andthe evolution of thematerials for life	(c) JAXA, 東大など

(c) JAXA/NHK

19	

３．Expecta(on	
  for	
  sample	
  analysis
	Initial analysis of the Ryugu sample (2021–)!
・ Scientific desciprtion of the Ryugu sample!
・ Scientific understanding of the observations of the material. !
・ Information leading to greater understanding of the origin of the
Solar System, the oceans on the Earth and the evolution of thematerials for life.!
6 teams:	
1. Chemical analysis team	
2. Petrology and mineralogy team for the coarse sample	
3. Petrology and mineralogy team for the fine grain sample	
4. Volatile materials analysis team	
5. Condensed organic matter analysis team	
6. Organic molecule analysis team 	

・Present scientific signifcance of the Ryugu sample. 	

20	

４．Initial observational results with the midinfrared camera!
Outline of the TIR observation	
★Observation & Operation of the TIR	Light curve released	

06/06 	TIR observation check	
06/07 	Ryugu light curve observation （１）＠2000km，diameter ～0.5 pixels.	
06/18 	Ryugu light curve observation （２）＠200km, diameter ～5 pixels.	
06/09-22 Ryugu ・１ shot imaging（almost daily）	
	
Ryugu is getting bigger (now) 	
!!
06/27 ＜Arrival at Ryugu＞	
06/29 	Dark observation（orientated towards deep space）	
06/30 	Global observation of Ryugu （１）＠20km，diameter～50 pixels.	
07/02 	Observation to survey image distortion	
07/03 	TIR observation program update 		
Thermography published（now）!!
	

21	

４．Initial observational results with the midinfrared camera!
Ryugu growing steadily larger!

Provided by：JAXA, U. of Aizu, Rikkyo U, Chiba Institute of Technology, Ashikaga U., Hokkaido University of Education, Hokkaido Kitami Hokuto
High School, AIST, National Institute for Environmental Studies, U. of Tokyo, DLR, Max Planck Institute, Stirling U.	

22	

４．Initial observational results with the midinfrared camera!
TIR Thermography（１ rotation）!
Image date & time：June 30, 2018, 07:02 – 14:45（UTC），every 8 minute，１ rotation!
Image capture location ：20 km altitude above Ryugu （home position），~20m／pixel!
Solar distance：0.987AU（1AU：annual average distance between the Earth and Sun：~1.496 billion km）!

High T	

Low T	

(animation）	

Provided by：JAXA, U. of Aizu, Rikkyo U, Chiba Institute of Technology, Ashikaga U., Hokkaido University of Education, Hokkaido Kitami Hokuto
High School, AIST, National Institute for Environmental Studies, U. of Tokyo, DLR, Max Planck Institute, Stirling U.	

23	

４．Initial observational results with the midinfrared camera!
TIR Thermography（feature）!
Image date & time：June 30, 2018, 07:02 – 14:45（UTC），every 8 minute，１ rotation!
Image capture location ：20 km altitude above Ryugu （home position），~20m／pixel!
Solar distance：0.987AU（1AU：annual average distance between the Earth and Sun：~1.496 billion km）!

★Main features		・Capture of the characteristic terrain（overall shape，huge crater・boulder）	
	・North-South temperature difference	（seasonal change due to inclination ofrotation axis: summer/winter ）		・Morning ～noon～evening
temperature cycle captures		・Absolute temperature (in progress)	

High T	

Low T	

Provided by：JAXA, U. of Aizu, Rikkyo U, Chiba Institute of Technology, Ashikaga U., Hokkaido University of Education, Hokkaido Kitami Hokuto
High School, AIST, National Institute for Environmental Studies, U. of Tokyo, DLR, Max Planck Institute, Stirling U.	

24	Ref: from fact sheet	

Science: Elucidating the birth and evolution of the Solar System	

Crosssections	

Topics	Primitive Solar System disk (gas + dust)	

Planetoids	
Dust → Planetoid formation	

① Investigating the materials thatformed the planets	
What materials existed in theprimitive Solar System disk, andhow did they change up to theformation of planets?	

Primitive planets	
Coalescence of planets	

Terrestrial planet formation	

② Investigating the formation processesof the planets	
How do celestial bodies growfrom planetoids to planets?	

Gas giant formation	

Loss of solar disk, completionof Solar System	

25	

Ref: from fact sheet	② Investigating planetary formation
	
Rubble pile body
Planetoids
Dust(Minerals, water, organics)

ImpactMetal
core

PlanetDifferentiated body

• Elucidate the structure of planetoids that eventually became planets.
• Elucidate what processes occurred during the collisions, coalescence, and accumulationof celestial bodies.
↓
Elucidate formation processes from planetoid to planet

Keywords:• Rubble pile body： A celestial body formed from accumulated rubble• Impacts and coalescence: When celestial bodies collide, the resulting fragments can
combine to form a new body• Accumulation: Accumulation of fragments resulting from a collision via the force ofgravity26	

４．Initial observational results with the midinfrared camera!
Contribution of the TIR to the Landing Site Selection (LSS)!
★Science objectives：scientific features of asteroid Ryugu	
u Estimation of geological features at the asteroid surface layer （rocky, gravel, sand etc）	
u Interpretation of spectroscopic data（eliminate influence from particle size voids and headradiation)	
u Sample selection and yield （select region where a sample with varying particle sizes can becollected）	

★Mission objectives：perform safe & reliable operation of the spacecraft	u Increase in sample yield (select region with particle sizes suitable for collection by sampler)	
u Temperature forecast (exclude areas that are too hot for the spacecraft) 	
u Avoid obstacles (select from regions with less dangerous rock masses for the spacecraft)	

Thermalinertia	Void ratio	Surfacestructure	Particle size	

Spectroscopic
interpretation 	

Boulders	

Sample yield	

TIR	
Thermalimaging	Collision risk	Temperature
distribution	

Max. Temp.	

T forecast	

Science obj.	

Mission obj,	

27	

４．Initial observational results with the midinfrared camera!
TIR Observation：summary!
•Successful global thermal imaging of the asteroid (excluding part of thepolar regions) by TIR!
This is a first for two-dimensional imaging of a small body at 10μm
!

•
!
!
•

Detection of characteristic terrain and seasonal changes on asteroid
Ryugu by thermal imaging! !
Overall shape, huge crater and boulders, north and south temperature difference.!

Measurement of thermophysical characteristics of the “boulder”
originating from within the parent body! ⇒ Future detailed
investigation !

Elucidate the formation of asteroid Ryugu and the process of internal
evolution!!

!
•

Acquire information on both science and mission necessary forselecting landing sites!!

Particle size distribution, temperature environment, collision
avoidance etc. 	

28	

５．Mission Schedule	Current operation plan!
• Normal observation is from the Home Position with an altitude of about
20 km ＝ BOX-A!
• Lower altitude operations: !
Ø BOX-C operation：Jul. 17-2, lowest altitude approximately 6km（7/20〜22）!
Ø Medium & high altitude operation：Aug. 1-2, lowest altitude
approximately 5km （8/1）!
Ø Gravity measurement and descent operation: Aug. 6-7, lowest
altitude approximately 1km（8/7）!
•

Tour observation!
Ø BOX-B operation：late Aug. !

※ “BOX” is explained on the following slide!

29	

５．Mission Schedule	
Earth	 Sun	Home position
coordinate system（XHP, YHP, ZHP）	

“BOX” definition	
BOX-A	

（Reference material）	
BOX-B	BOX YHP-direction size	

BOX-C	

BOX-A operation：operations while hovering at
20km altitude. Regular operation standard.
BOX-B operation：Tour observation. Hovering
area extended horizontally to enable
observations to either side of the asteroid.
asteroid averageradius	asteroid center of mass	

BOX-C operation：Hovering area extended
vertically to enable observations at low
altitude. 	

30	

５．Mission Schedule	
BOX-C operation summary	Altitude	Home Position	

Time	

7/23	

7/17	

	

7/20〜22	

31	

５．Mission Schedule	
Medium height descent summary	Altitude	Descent	Directobservation(during descent)	

Directobservation(home positiion)	

Directobs.

Return toHome Position	

(during
ascent)	

Home Position	

8 hours	

24 hours	

8/1~10:00	
	
10時頃

8/1
20時頃
~20:00		

8/2
8時頃	
~08:00	

8/2
18時頃
	~18:00	※ Time in JST. This may change depending on adjustments in the operation plan and situation 	

time	

32	

５．Mission Schedule	
Medium height descent summary
	No	Phase	

Overview	

Al4tude	１	
 Descent	
  from	  Home	   Descent	
  from	  Home	  Posi4on.	
  Use	  the	
  same	  Posi4on	descent	
  technique	
  (GCP-­‐NAV)	
  as	
  touchdown.	
  NIRS3	  is	
  ON.	
  	

20〜7	
  km	

２	
 Direct	
  Observa4ons	  ONC-­‐T、TIR	
  observa4ons	
  start.	
  Directly	
  image	  surface	
  below.	
  	

7〜5	
  km	

３	
 Direct	
  Observa4ons	  While	
  maintaining	
  5km	  al4tude,	
  directly	
  image	  surface	
  below.	

5	
  km	

４	
 Direct	
  Observa4ons	
  

ATer	
  accelera4ng	
  to	
  ascend,	
  directly	
  image	  the	
   5〜7	
  km	
surface	
  below	  un4l	  an	
  al4tude	  of	
  7km.	

５	
 Return	  to	
  Home	  While	
  ascending,	
  begin	
  the	
  data	  downlink	  	(Descending)	
(Hovering)	

(Ascending)	
Posi4on	

7〜20	
  km	

※For GCP-NAV see next slide.	

33	

５．Mission Schedule	
Comparison between medium height descent operation and BOX-C operation	
Phase	

Medium	  height	
  descent	BOX-­‐C	
  opera4on	

Descent	
  4me	

Half-­‐day	

Descent	
  over	  several	
  days	Posi4on	  control	
  during	  descent	
  	

GCP-­‐NAV	

HPNAV	

Posi4on	  control	
  GCP-­‐NAV	
  during	  observa4ons	
 Hovering	
  using	  HPNAV	Free	
  mo4on	  depending	  on	  advanced	  ΔV	

Observa4on	
  4me	8	
  hours	

About	  10	  hour	Observa4on	
  angle	+Z	
  towards	
  Earth	Scan	
  opera4on	
  implemented	

Opera4on	
  concept	

Reduce	  al4tude	  and	
  observe	
  at	
  a	
  
target	  point	  and	
  angle.	
  (Precisely	
  guide	
  down	  to	  a	
  target	
  point	
  in	
  the	  same	
  manner	
  as	
  landing)	

Reduce	  al4tude	
  while	  hovering.	
  (Approximately	
  reduce	  the	  al4tude	  by	
  extending	
  the	
  same	  hovering	
  technology)	

Note：GCP-NAV (Ground Control Point Navigation)→ A method of finding the position & speed of the spacecraft by observing features on the asteroid surface.
HPNAV (Home Position Navigation)→ A method of finding the position & speed of the spacecraft from the direction to the image center and attitude data of
the spacecraft	

34	

５．Mission Schedule	
Gravity measurement descent operation overview
	
Altitude	Home Position	

Track ΔV	

about	time	
8/6
~10:00	
10時頃
	

8/6
20時頃
~20:00		

8/7
7時頃	
~07:00	

8/7~16:00		
16時頃※ Time in JST. This may change depending on adjustments in the operation plan and situation 	

35	

5．Mission schedule	
Year	

Month, day	Event	

2018	

January 10	
June 3	
June 3	
June 27	
End of July	
August	Late August	
Sept - Oct	Sept - Oct	Nov - Dec	January	
February	Mar - Apr	Apr - May	July	
Aug - Nov	Nov - Dec	Third stage of ion engine operation begins	Complete	
Ion engine operation ends	
Complete	
Start of asteroid approach (distance: 3100km）	
 Complete	
Arrival at asteroid Ryugu (altitude 20km）	
Complete	
Medium altitude observations #1（alt. 5km）	
Planning	
Decent to measure gravity （alt.1km）	
Planning	
Determination of landing site	Planning	Period for touchdown operation #1	
Planning	Period for rover deployment #1	
Planning	
Solar conjunction (communication unavailable)	
 Planning	Medium altitude observations #2（alt. 5km）	
Planning	Period for touchdown operation #2	
Planning	
Crater generation operation	
Planning	Period for touchdown operation #3	
Planning	Period for rover deployment #2	
Planning	Remain near asteroid	Planning	
Departure from asteroid	Planning	

2019	

Status	This schedule may be changed for multiple factors after arrival at Ryugu. Please note
therefore, that the situation is not fixed, except where marked ‘Complete’.	

36	

６．Future	
  Plans	■Media coverage and information release:	
• Schedule for press briefing in August： August 2, August 23		■Outreach events	Ø JAXA Sagamihara open campus:	
• July 27-28, there is a Hayabusa2 corner 	Ø Children’s event (in Japanese)	
• Why Hayabusa2? Any questions classroom 	• Sept 2（Sunday）2 – 4 pm	
• Sagamihara City Museum 	• Online broadcast planned		37	

Reference	
  material	38	Home Position Coordinate System	
Earth	

Sun	

ZHP	

YHP	
Ryugu	XHP	39	

Primary	
  spacecraT	
  components	
Deployable camera(DCAM3)	

X-band lowX-band high- gain antenna	
gain antenna	

Solar array paddle	

X-band midgain antenna	
Ka-band highgain antenna	Optical navigation Laser altimeter
cameraLIDAR	
ONC-T	

Near-infrared
spectrometer
NIRS3	

Thermal infrared
cameraTIR	

Scientific observation equipment
Star trackers	

Ion engine	Near-infrared spectrometer(NIRS3)	

RCS thrusters	
Optical navigation
cameraONC-T, ONC-W1	

Re-entry capsule	Sampler horn	

Laser altimeter(LIDAR)	

Optical navigation
camera ONC-W2	

Small lander & rover	
MASCOT	

Minerva ２
	

MASCOT lander	
Thermal infrared camera(TIR)	

II-1A	

II-1B	

II-2	Created by DLR and II-1: By the JAXA Minerva-II team	
CNES	
II-2: By Tohoku Univ. & the Minerva-II
Consortium	

Minerva-II rover	

Small carry-on impactor (SCI)	
Target markers × 5	Size： 1 ×1. 6×1. 25 m (main body)
Solar paddle deployed width 6 m
Mass ： 609 kg (incl. fuel)	

40	

Remote	  sensing	  equipment
	Optical Navigation Camera (ONC）

ONC-T (telephoto)

Thermal Infrared Camera (TIR）

ONC-W1,W2 (wide-angle)

Imaging for scientific observation and navigation

Near-infrared Spectrometer (NIRS3）

Infrared spectra including the 3-µm band:
investigates mineral distributions on the asteroid
surface

8–12 µm imaging: Measures asteroid surface temperature

Laser Altimeter (LIDAR）

Measures distance between the asteroid and the spacecraft
in a range of 30 m–25 km

41	Op4cal	
  naviga4on	
  camera	
  (ONC）	
ONC：Optical Navigation Camera
Objective: Images fixed stars and the target
asteroid for spacecraft guidance andscientific measurements	
Scientific measurements：• Form and motion of the asteroid:
Diameter, volume, direction of inertial principal axis,
nutation• Global observations of surface topography
Craters, structural topography, rubble, regolith
distribution• Global observations of spectroscopic properties of
surface materials
Hydrous mineral distribution, distribution of organic
matter, degree of space weathering• High-resolution imaging near the sampling point
Size, form, degree of bonding, and heterogeneity ofsurface particles; observation of sampler projectiles
and surface markings

ONC-­‐T	
Detector	• Elucidation of features of target asteroid• Distribution of hydrous minerals andorganic matter, space weathering,boulders• Sampling site selection• Basic information on where to collectasteroid samples• Ascertaining sample state• High-resolution imaging of sampling sites	

W1
FoV	
T
FoV	

ONC-­‐W1	

ONC-­‐W2	

2D	
  Si-­‐CCD	  	  (1024	
  ×	
  1024	  px)	

Viewing	  direc(on	Downward	
  (telephoto)	

Downward	
  (wide-­‐angle)	

Sideward	
  (wide-­‐angle)	
  Viewing	
  angle	

6.35°	  ×	  6.35°�

65.24°	  ×	
  65.24°�

Focal	
  length	

100	
  m–∞	  1	  m–∞	

Spa(al	  resolu(on	1	
  m/px	
  	
  	
  @	
  10-­‐km	
  alt.	
  1	
  cm/px	
  @100-­‐m	
  alt.	
  

	
  	
  	
  10	
  m/px	  	
  @10-­‐km	
  alt.	
  1	
  mm/px	
  @1-­‐m	
  alt.	

Observa(on	
  wavelength	

390,	
  480,	
  550,	
  700,	
  860,	
  950,	
  589.5	
  nm,	
  and	
  wide	  �

485–655	
  nm	

42	

Thermal infrared camera (TIR）	
TIR=Thermal Infrared Imager	
The surface temperature of the asteroid changes overthe day, rising in sunlight and decreasing at night.
Diurnal change in surface temperature is large in finesoils like sand and highly porous rock, and small in
dense rock.
We will examine the physical state of the asteroid’s
surface by 2D imaging (thermography) of thermalradiation from the asteroid.

Large	

400	
  
350	
  

Temp
(K)	
 [K]
Temperature	  : 2D uncooled bolometer: 8–12 µm: –40 to 150 °C: 0.3 °C
: 328 × 248 (effective): 16°×12°: 20 m (20-km alt.）
5 cm (50-m alt.）

Stone	

Gravel	Sand	・ Detector
・ Observation wavelength
・ Observed temperatures
・ Relative accuracy
・ Dimensions
・ Viewing angle
・ Resolution

Small

Temperature change	

Night
	

Night	

Day
	

I=10

300	
  

I=50
I=100

250	
  

I=200

200	
  

I=500

150	
  
100	
  
-180

I=1000

I=2000
-135

-90

-45

0

45

Longitude	  [deg] 	Longitude

90

135

180

43	

Laser	  al4meter	
  (LIDAR）	
LIDAR: Light Detection And Ranging	
・Pulse-type laser altimeter・ A pulse YAG laser with a 1.064-µm
wavelength is emitted toward the target
object, and the altitude is measured bymeasuring the return time of the laser
beam.
・ The LIDAR aboard Hayabusa 2 could
perform measurements from 30 m–25 km.
・ LIDAR is a navigation sensor used forapproach and landing at a target, and ascientific observation device used tomeasure shape, gravity, and surface
characteristics, and for dust observations.
・ It also has a transponder function that canperform space laser ranging (SLR)
experiments with ground LIDAR stations.

Short-range telescope	Beam expander for illumination	

Long-range Cassegrain telescope	
Laser altimeter engineering model	
Scientific objectives• Terrain and gravity field observations of thetarget asteroid• Observations of albedo distribution at various
surface points• Observations of dust floating around theasteroid• Asteroid form, mass, porosity, and deviation• Asteroid surface roughness• Dust floating phenomena

44	Near-­‐infrared	
  spectrometer	
  (NIRS3)	
NIRS3: Near-infrared Spectrometer(‘3’ from 3 µm)	Infrared absorption of hydroxyl groups and watermolecules is observed in 3-µm band reflection spectra in
the near-infrared region. NIRS3 investigates distributionsof hydrous minerals on the asteroid surface by measuringreflection spectra in the 3-µm band.

OH	
 H2O	

Observation wavelength range: 1.8–3.2 µm
Wavelength resolution: 20 nm
Full field of view: 0.1 deg
Spatial resolution: 35 m (20-km alt.)
2 m (1-km alt.）• Detector temperature: –85 to –70 °C• S/N ratio: 50+ (wavelength 2.6 µm)

Orgueil (CI)

Absorption form anddepth vary dependingon the type andamount of hydrous
mineral	

1.5
Scaledreflectance	Reflectance
Relative••••

Murchison (CM)1.0

Renazzo (CR)Near-infrared reflection
spectra ofcarbonaceouschondrites	

0.5

Allende (CV)

0.0

2.0

2.5
Wavelength (µm)

3.0Wavelength (µm)	

45