Operation status for the asteroid
explorer, Hayabusa2
October 23, 2018
JAXA Hayabusa2 ProjectContents TodayRegarding Hayabusa2:;Report on TD1-R1-A;TD1-R3 operation plan

TD1-R1-A ETouchdown 1 rehearsal 1A (equivalent to the second rehearsal)
TD1-R39ETouchdown 1 rehearsal 3 (equivalent to the third rehearsal)



Topics
?>Hayabusa2 overview & mission flow outline@>Project status & overall schedule
A>TD1-R1-A operation report
B>TD1-R3 operation plan
C>Press conference at DPS
D>Future plans
TD1-R1-A ETouchdown 1 rehearsal 1A (equivalent to the second rehearsal)
TD1-R39ETouchdown 1 rehearsal 3 (equivalent to the third rehearsal)
DPSEDivision for Planetary Sciences of the American Astronomical Society<one of the world’s largest meetings for planetary science=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 returnexploration (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 ofits 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 thedistribution, origins, and evolution of materials in the solar system.

International positioningE;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. Inaddition 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.

(Illustration: Akihiro Ikeshita)
Hayabusa 2 primary specifications
MassApprox. 609 kgLaunch
3 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, 20189▲
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 statusE
– Second rehearsal for touchdown, TD1-R1-A, was performed between
October 14 – 16. The spacecraft descended to an altitude of 22.3m on
October 15 and confirmed the functionality of the LRF.
– The third rehearsal for the first touchdown (TD1-R3) will be held from
October 23 – 25 (already started).
Schedule overview:
2015
312

Event	

-*2*#+
./'0#2*.-2016
10 12

!

launch	'% 2017

4

15*-($7#0 3-.30-'72.#12'0.*&

2020
12

Arrival at Ryugu	3-' 

''-21207
#02)0'230-12'0.*&/0.6*,*27./'0#2*.-1

Earth swing-by	
'% #0 #7

2019

6 7
#//0.#%)

<"=2'12./'0#2*.-1 Southern hemisphere station
operations (CAN/MLG)	
#7  %2
#7

Ion engine operations ※	

2018

Departure from Ryugu	.4F'%

Capsule re-entry	
#2'  

Optical navigation	 Solar conjunction	#7 3+ .4'%
.4

/0

#-

3- 



2. TD1-R1-A operation report
TD1-R1-A purposel Confirmation of navigation guidance accuracy at low altitude(altitude less than 40m).
l Confirmation of operation characteristics of LRF (Laser RangeFinder) that measures altitude at short distances.
8This is the second rehearsal for the touchdown, but repeated
operations that could not be competed during the first rehearsal(TD1-R1, September 10-12). We therefore refer to this as TD1R1-A. (To avoid confusion, the name TD1-R2 will not be usedas this is the name of a second rehearsal planned for the firsttime.)


2. TD1-R1-A operation report
TD1-R1-A operation

AltitudeReturn to home position
Home position

99920km

GCP-NAV (Ground Control Point Navigation)
99→Method of determining the position andspeed of the spacecraft by observingcharacteristic points on the asteroidsurface.

Deceleration ΔV5km
40m

Increase ΔVHPNAV (Home Position Navigation)
99→Method of determining the position andspeed of the spacecraft from direction ofthe center of the asteroid image andattitude of the probe.

Time(JST)

©JAXA

10/14
23:50

10/15
10:10

Lowest altitude: 22.3m
10/15 22:44

10/16
15:00



2. TD1-R1-A operation reportTrajectory record from LIDAR to LRF
©JAXA

Altitude measurement value using LIDAR (green) and the LRF (yellow) almost
coincide over the overlapping altitudes from 27m to 25m, indicating the altitude
measurement was inherited correctly from LIDAR to LRF.



2. TD1-R1-A operation reportLevel of accuracy in navigation guidanceIn this operation in which the spacecraft descend to an altitude of22.3m, the level of accuracy recorded was 10.8 on the asteroid
surface. 

2. TD1-R1-A operation report
New image

Image captured by the ONC-W1 near lowest point

6m
Image taken with the ONC-W1 at analtitude of about 47m. Capture time
was October 15, 2018 at 22:45 JST.

<Image creditEJAXA, University of Tokyo,Kochi University, Rikkyo University, Nagoya
University. Chiba Institute of Technology, Meiji
University, Aizu University, AIST.)

2. TD1-R1-A operation report
New image

Image captured by the ONC-W1 near lowest pointRed circle marks the candidate
touchdown site, L08-B.

Image taken with the ONC-W1 at analtitude of about 47m. Capture time
was October 15, 2018 at 22:45 JST.

<Image creditEJAXA, University of Tokyo,
Kochi University, Rikkyo University, Nagoya
University. Chiba Institute of Technology, Meiji
University, Aizu University, AIST.)

3. TD1-R3 operation planFrom October 23 - 25, the third rehearsal for touchdown
will be performed.
■AimE Confirm the accuracy of the navigation guidance control
at low altitude by the following steps.
E Use the measured LRF<Laser Range Finder= value tocontrol the spacecraft.
E If conditions are satisfactory, release a target marker.
E Track released target marker.
3. TD1-R3 operation plan
TD1-R3 schedule

AltitudeReturn to home position
Home position

99920km

Target marker
separation
Deceleration ΔV5km
~40m

Increase ΔV

GCP-NAV (Ground Control Point Navigation)
99→Method of determining the position andspeed of the spacecraft by observing
characteristic points on the asteroidsurface.
HPNAV (Home Position Navigation)
99→Method of determining the position andspeed of the spacecraft from direction of
the center of the asteroid image andattitude of the probe.

Time(JST)

©JAXA

10/24~13:0010/124~23:00

10/25~12:0010/26

3. TD1-R3 operation plan
TD1-R3 low altitude sequence
Descent at
10cm/s while
using LIDAR.

After tracking TM,
ascend and returnto 20km altitude.

LIDAR altitude measurement

Begin LRF altitudecontrol from ~25m
altitude.

Lateral thruster
injection tosynchronize withasteroid rotation
speed.

Descend a few meters
while pushing TM
towards surface toseparate.TMseparation

Maintain ~20m
altitude while
tracking TM withcamera

25m

20m
FLASHuse

TM track0m


3. TD1-R3 operation planTarget marker

E Size of body (ball): about 10cm
E Retroreflective film
E 4 barsErolling prevention
E Inside contains many polyimide globules

A

B

C

D

E

E First to separateEB
E On the inside of the target marker is asheet on which is written the names ofmembers from the general public. 4. Press conference at DPSDPS = Division for Planetary Sciences of the American Astronomical
Society<one of the world’s largest academic societies inplanetary science, date/place: October 21 – 26, Knoxville, USA=E Hayabusa2 press conference: October 25, 12:1513:15 <October
26, 01:1502:15 JST=E InformationEhttps://aas.org/meetings/dps50/2nd-media-advisory
E TitleEHayabusa2 Explores Asteroid Ryugu
E Presenters<titles omitted=EMasaki Fujimoto<JAXA=:Hikaru

Yabuta<Hiroshima U.=, Eri Tatsumi<U. Tokyo=:Deborah Domingue (PlanetaryScience Institute):Lucille Le Corre (Planetary Science Institute):Ralf Jaumann(German Aerospace Center)

E New informationEalso to be released in Japan
8Hayabusa2 special session in DPS
99;Oct 25 (Poster presentation : 13), Oct 26 (Oral presentations : 9)5. Future plans■Scheduled operation
E October 23 – 25ETD1-R3<3rd touchdown rehearsal=■Press and media breifings
E November, 8 (Thurs)911:00F9Press briefing @ Ochanomizu
E December 6 (Thurs) 9Afternoon TBD9Press conference @Sagamihara