Asteroid explorer, Hayabusa2,reporter briefing

December 19, 2019
JAXA Hayabusa2 ProjectTopicsRegarding Hayabusa2,
Summary of near asteroid operations
The return cruise operation plan

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Hayabusa2 reporter briefing

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Contents
0. Hayabusa2 and mission flow outline
1. Current status and overall schedule of the project
2. Near-asteroid operations summaryJAXA
3. Near-asteroid operations summary (NEC)
4. Achievementspaper, awards
5. Return cruise operation plan
6. Future plans
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Hayabusa2 reporter briefing

3Overview of Hayabusa2ObjectiveWe 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 theprimitive solar system. By doing so, we will learn about the origin and evolution of Earth, the oceans, and life, andmaintain and develop the technologies for deep-space return exploration (as demonstrated with Hayabusa), a field
in which Japan leads the world.
Expected results and effects
By exploring a C-type asteroid, which is rich in water and organic materials, we will 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 of obtaining samples from acrater 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 of observation before and after projectile
impact from an impactor.
Comparison with results from Hayabusa will allow deeper understanding of the distribution, origins, andevolution of materials in the solar system.
International positioningJapan is a leader in the field of primitive body exploration, and visiting a type-C asteroid marks a newaccomplishment.
This mission builds on the originality and successes of the Hayabusa mission. In addition to developing planetaryscience 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 and otherwise promote scientific exchange, and expect furtherscientific findings through comparison and investigation of the results from both missions.

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Hayabusa2 reporter briefing

Hayabusa 2 primary specifications(Illustration: Akihiro Ikeshita)
MassApprox. 609 kg
Launch3 Dec 2014
MissionAsteroid returnArrival
27 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.

4Launch
Dec 3, 2014

Mission flow
Ryugu arrival

Earth swing-by
Dec 3, 2015

MINERVA-II-1 separation

June 27, 2018

Sep 21, 2018

MASCOT
separation
Oct 3, 2018

Ryugu
departure
Earth return
End of 2020

Nov 13, 2019

MINERVA-II2
separation
Oct. 3, 2019

(image credit: illustrations including spacecraft by Akihiro Ikeshita, others by JAXA)

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Secondtouchdown

Impactor (SCI)
5 April, 2019

July 11, 2019

Hayabusa2 reporter briefing

First touchdown
Feb 22, 20195

1. Current project status & schedule overview
Current
status7– On December 3 at 11:00 JST (on-board time), we entered the Earth Return Cruise withthe operation of three ion engines. Since December 14, operation has continued two ionengines.
– Hayabusa2 was selected for a Union session of the AGU (American Geophysical Union)
Autumn Meeting (9 – 13 December in San Francisco).

Scheduleoverview
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PPTD Prep Descent (retrial)

PPTD Prep Descent (Obs. Only)

PPTD (Touchdown to Crater)

TM Orbiting

MNERVA-II2 Orbiting/Landing

Ryugu Departure

PPTD (Touchdown to Crater)
PPTD Prep Descent (TM3)

TD1-R3 (TM drop)
TD1-R1A (rehearsal retrial)
MASCOT Landing
MNERVA-II1 Landing
TD1-R1 (rehearsal #1)

Conjunction

TD1

Descent Obs for TD2 prep

Pre-Impact SurveySCI (Kinetic Impact)

Post-Impact Survey

PPTD Prep Descent (TM drop)

PPTD StudyMNERVA-II2 Deployment

PPTD Prep Descent (TM2)
PPTD Prep Descent (TM1)
Post-Impact Decent
Pre-Impact Decent

SCI (Kinetic Impact)

TD2
TD2-R2 (rehearsal)

TD1
TD1-R2 (rehearsal #2)
RMASCOT Landing
MINERVA-I1 Landing
TD1-R1 (rehearsal #1)

Ryugu ArrivalPlan

LSS Decision Meeting
Gravity Mes. Descent
Gravity Mes. Descent
Mid-Altitude Obs
Mid-Altitude Obs.
LSS

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TM/MINERVA-II2Orbiter Study
Impact Site Selection

98753421121110987

Additional TD Study

Landing SiteSelection

101112

Critical Descent
TouchdownLanded Rovers
Artificial Crater
Used Target Marker
Orbiting Objects

Plan Actual1718
32
44
11
54: 032019
2018

While dealing with theunexpected environment ofRyugu, the asteroid
proximity operation wascompleted within the preplanned schedule forresources such as fuel andpersonnel.

Actual

2. Asteroid proximity operations summary (JAXA)

2. Near-asteroid operations summary (JAXA)Engineering achievements
7 world firsts:
1.
2.
3.
4.
5.
6.
7.

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Mobile activity of exploration robots on small body.
Multiple robots deployment on small body.
60cm-accuracy landing and sampling.
Artificial crater forming and observation of impact process.
Multiple landing on extra-terrestrial planet.
Access to subsurface material.
Smallest-object constellation around extra-terrestrial planet.

Hayabusa2 reporter briefing82. Near-asteroid operations summary (JAXA)
7 “world firsts” achieved by Hayabusa2

1. Mobile activity of exploration robots on small body.
2. Multiple robots deployment on small body.
MASCOT
immediately after
separation, imagedby the ONC-W2

TD accuracy59.8 cm
Moment of first
touchdown captured
with CAM-H

TM

Surface ofRyugu
captured byMINERVA-II1A.

C01-Cb(radius 3.5 m)
Hayabusa2 photographed by MINERVA-II1A

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MASCOT observation image

Hayabusa2 reporter briefing

2nd touchdown point & accuracy

3. 60cm-accuracy landing and sampling.
92. Near-asteroid operations summary (JAXA)
7 “world firsts” achieved by Hayabusa2
4. Artificial crater forming5.Multiple landing on extra-terrestrial planet.
and observation of impact 6. Access to subsurface material.
process.

30m TD2 target
landing point
Terrain around the20m
Artificial crater 2nd touchdown point

Moment of impact
captured with
DCAM3.

SCI crater

SCI impactpoint
SCI immediatelyafter separation
captured with
the ONC-W1.

Sampling point
Ejecta accumulation
around the artificial crater

MINERVA-II2 immediately after
separation, captured by ONC-W2

Artificial crater
made with the SCI

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Orbits of two target
markers around Ryugu.

Target marker

7. Smallest-object constellation around extra-terrestrial
planet.

Hayabusa2 reporter briefing10

2. Near-asteroid operations summary (JAXA)The NEC major contribution to the JAXA-NEC collaboration••

JAXA-NEC have established a close review system for operation review, which is now underway.
Exchange between the JAXA near-asteroid phase operation team and the NEC system team: approximately 8,000emails.
– FY2015: SWBY operation, feasibility study of near-asteroid phase schedule.
– FY2016: Detailed operation of various near-asteroid phase events, ground-tool renovation.
– FY2017: Contingency study, Landing Point Selection (LSS) training, Realtime Integrated Operation (RIO)training.
– FY20182019: Operations for the real Ryugu.
A challenging and reliable operation method was constructed with JAXA-NEC, through clarification of the divisionof roles, mutual checks performed so that roles overlapped, complement one another and utilize attributes.

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JAXANEC

Document management

Overall analysis

Elaboration

Schedule management

Flexible

StrictPlan revision / policy change proposal

Proactive

Prudent (not passive)

Hayabusa2 reporter briefing112. Near-asteroid operations summary (JAXA)The NEC major contribution to the JAXA-NEC collaboration••••l

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As the system maker, NEC know everything about the spacecraft.
– Spacecraft status can be quickly grasped. Immediately deal with problems.
Preparation of detailed planning documents and shift management.
– Creation of large operation plan, management and quick revision.
Create and review huge, complex procedures.
– Number of procedure lines for TD1: over 80,000 lines. Over 1.2 million lines for the entire
descent operation.
– Reliable procedure review (manual confirmation of procedure, with JAXA and NEC mutuallychecking over 1,000 cases.)
Strict management of operation preparation for implementation.
– Schedule management at the time JAXA provided information.
ONE TEAM built through discussions on the same playing field.
– From a realistic standpoint, a relationship is built by saying NO if something cannot be done.
Hayabusa2 reporter briefing122. Near-asteroid operations summary (JAXA)
Examples of JAXA-NEC collaboration
Preparation for 1st touchdown• With Ryugu having minimal flat areas, both JAXA and NEC recognised the difficulties
and sought a safe and secure path, resulting in a significant change in procedure fromthe initial plan.

– Procedural change to separate TM in advance of touchdown.
– To ensure safety and accuracy, LRF distance measurement values were “fooled” based on premeasured terrain information.
Bold policy change to use software differently from traditional usage.
Implemented swift change for touchdown operation at the beginning of 2019.
• JAXA developed and proposed this method on December 27, 2018.
• NEC instantly considered the proposal and performed simulations to demonstrate feasibility.
• Policy decision on January 7, 2019.
• Confirmation of simulation results by both JAXA and NEC until just before operation on February 22.

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Hayabusa2 reporter briefing13

2. Near-asteroid operations summary (JAXA)
Examples of JAXA-NEC collaboration• [Training] The plan drafted by NEC was almost perfect, with issues difficult to find. Training was used to flag anyproblems. Through the training, JAXA provided appropriate feedback and NEC also had the opportunity to noticepotential improvements.
• [Landing feasibility study] JAXA’s plan for TD1 changed repeatedly. Initially, plans were made to enhance LRF
obstacle detection, followed by a method to use multiple target markers, and finally the current TD method. NEC
responded flexibly to these changes. While strictly observing the constraints of the spacecraft, they were open tochange and not bound to the initial plan.
• [1st touchdown] During the actual operation, JAXA-NEC understood one another’s roles and were willing to makenecessary decisions. During TD1, half of the decision to continue operation with a delay of five hours was made byNEC.
• [2nd touchdown] Strict measures were required to prevent lens fogging. TD2 was scheduled to be implemented at theend of June, and NEC made all necessarily preparations for this time. However, JAXA determined that fatigue of theJAXA-NEC site members had reached a peak, and that JAXA needed time to handle the remaining work up to TD2. As
a result, the implementation date of TD2 was July 11. Working transparently within the teams led to the ultimate
success.
• [NEC response to TD1/TD2] In addition to the NEC members of Hayabusa2, many NEC senior members from the first
Hayabusa era expressed messages showing pleasure and congratulations. The fact that Hayabusa2 was able to perfectly
accomplish the homework left by Hayabusa through building on the strengths of the Hayabusa management produced alarge reward in terms of the development of exploration technology.
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3Near-asteroid operations summary (NEC)    

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4. Achievements (papers, awards
 Near-asteroid operation period (after June 2018)
Papers
• Science journal: 4 articles, Nature Astronomy: 1 article, other major journals:11 articles.
• Many papers are also currently being submitted.
Commendations• Total of 8 awards• Award organization names
Aviation Week & Space Technology, The Japan Society for Aeronautical andSpace Science, Toray Science Foundation, Cool Japan Council, Airbus,
Japan SF Fan Group Federation, The Robotics Society of Japan, IEICE DCResearch Group.
Refer to reference material
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5. Return cruise operation plan•

Current status of Hayabusa2•

Trajectory control during the return phase•

Ion engine operation plan– Integrity of ion engine thrusters A, C and D has been confirmed (November 20 – 29, 2019).
 Thruster B is being preserved.
– As of today Dec 19, 2019, Hayabusa2 is a distance of 45,000 km from Ryugu.

–––––Consists of 2 phases of ion engine operation and the re-entry precision guidance.
1st ion engine operation period: Dec 3, 2019 – early February 2020.
2nd ion engine operation period: May 2020 – Sept 2020.
Re-entry precision guidance period: from Oct 2020 to re-entry.
Ballistic flight during periods other than the above. Take an Earth-oriented attitude for high-speed datalinks as needed.

– 1st ion engine operation period: Approx. 600 hours Thrusters used 3→2total acceleration approx.
100m/s– 2nd ion engine operation period: Approx. 1,900 hours Thrusters used 1→2total acceleration approx.
150m/s
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5. Return cruise operation plan
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6. Future plans Operation schedule
Until early Feb 2020
Press briefings, etc.
Feb. 2020TBD)

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ion engine operation

Press conference @ Tokyo Office

Hayabusa2 reporter briefing

19Reference

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Science, Nature list of papers• R. Jaumann, et al., Images from the surface of asteroid Ryugu show rocks similar tocarbonaceous chondrite meteorites, Science 23 Aug 2019, Vol. 365, Issue 6455, pp. 817-820• M. Grott, et al., High porosity boulders identified on C-type asteroid (162173) Ryugu,
Nature Astronomy volume 3, pages 971–976, 2019
• S. Sugita, et al., The geomorphology, color, and thermal properties of Ryugu: Implications
for parent-body processes, Science 19 Apr 2019: Vol. 364, Issue 6437, eaaw0422• S. Watanabe, et al., Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu—Aspinning top–shaped rubble pile, Science 19 Apr 2019: Vol. 364, Issue 6437, pp. 268-272• K. Kitazato, et al., The surface composition of asteroid 162173 Ryugu from Hayabusa2
near-infrared spectroscopy, Science 19 Apr 2019: Vol. 364, Issue 6437, pp. 272-275

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Award list
Data

Recognized person, group name, affiliation

Award content

Award organization

Award title

2019/11

Hiroki HiharaJunpei SanoTetsuya Masuda
Hisaki OtakeTatsuaki OkadaNaoko OgawaYuichi Tsuda

Reliability evaluation of Hayabusa2 opticalnavigation equipment ~ On-orbit demonstration of ahighly reliable system that meets resource constraints.

IEICE DC Research Group

6th Research Meeting Best Presentation Award

2019/09

Tetsuo Yoshimitsu, Takashi Kubota

Development of the asteroid exploration rover,
MINERVA-II

The Robotics Society of Japan

2019 Practical Use Technology Award

2019/07

Hayabusa2 ProjectMINERVA-II Ryugu landing and asteroid explorationby moving

Japap SF Fan Group Federation

2019 50th Seiun Award in the Free Category.

2019/06

Hayabusa2 Project

MASCOT onboard camera

AirbusAirbus Space Day Hayabusa2 Special Award

2019/05

JAXA Hayabusa Hayabusa2

Space equipment that brings together sophisticatedtechnologies is Japan Cool!

Cool Japan Council

COOL JAPAN AWARD 2019 [Generalsection] Outbound category.

2019/03

JAXA ISAS Director Hitoshi Kuninaka

Research & Development of microwave discharge ion
engine and promotion of Solar System exploration.

Toray Science Foundation2018 (59th) Toray Science and TechnologyAward

2019/03

JAXA Hayabusa2 Project Team (Represented byProject Manager Yuichi Tsuda)

Advances in deep space navigation technology forsmall body rendezvous with Hayabusa2 and arrival atasteroid Ryugu.

The Japan Society for Aeronautical andSpace Science

Technology Award, Project Category

Japan Aerospace Exploration Agency Hayabusa2

Japan's Hayabusa2 sample-return mission, which
rendezvoused with the asteroid Ryugu in June 2018,has made a promising start, with the successful
deployment and operation of three mini-rovers—one
from the DLR and Onera—ahead of its first landing
planned in early 2019.

Aviation Week & Space Technology

Aviation Week Network’s 62nd Annual
Laureate Awards, Space: Technology &Innovation

2019/03

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