Bio-Medical Information Networks
Professor Tohru Ifukube

Robotization and Artificial Intelligence
Toward Realization ofa Space Environment Preservation System

IInterviewer: Takashi Mikuriya, professor

̶̶ Professor Machida, I understand you graduated from theapplicability.

Department of Precision Engineering, Faculty of Engineering
at Hokkaido University. Were you interested from the̶̶ Is f i f teen ye ar s a shor t t i m e - f r ame in the world ofbeginning in pursuing research on outer space?

science and technology?

Well, no. It was sheer chance, actually. I originally wanted toIt is very short in space research, since you have to do flight

get into the National Institute of Radiological Sciences, but there

demonstrat ions. When I sat down to think about what towere no slots open that year. So I went into the Electrotechnicaldo next af ter those f i f teen years of research, I imagined

Laboratory instead, and because of my background in precision

what outer space would be like in twenty years and tried toengineering I conducted research on adaptive control forcome up with an idea for technological research that would

precision processing of electronic materials. I later took up

be needed dur ing that t ime span. The space shut tle hadsomebody's suggestion that I start "doing space", and that's

just gone oper at iona l at the time, and the inf rastructure

when I made the transition.

was beginning to develop in space. I started look into
robot ics based on the thought that we would need ser vices,̶̶How did you feel at the time about "doing space"?

construct ion, and maintenance for the infrastructure.

There are always dreams and hopes in space, of cour se, but

Many new component technologies are required for robots

it was also a time when Japan was just beginning to work onthat work in the extreme environment l ike in outer space,

space development with its own technology. There weren't

and it felt like a wor thwhile technologi ca l endeavor toany established systems in place, and I started research on

make such robot s. I considered it a challenging theme

space development because I saw an oppor tunity in thatfrom the standpoint both of component t echnologies andsituat ion to do some innovative work. My theme at the timeof int egra ted t echnologies, because those component

was "ion engines". It's the kind of thing you see in science

technologies have to come together in some way as systems

fict ion - turn propellant into plasma, extract ions with highto f unc t ion independent l y. Thi s was why I went into

voltage, accelerate them to get thrust. Seeing a jet of blue

the f ield, and also because I f el t that putt ing robots andf lash when it fired up in the vacuum chamber simulating

space together could give people dreams and hopes evenspace env i ro nmen t, I hone s tly got exc ited visualizing

more (laughter). Looking ahead, in my opinion the spacesomething like that flying through space.

development is going to continue as a collaborat ive ef fort
between robots and human beings.

̶̶So the "allure of the blue flash"captured your imagination?
̶̶Are robots that work in space greatly different from theYes, it did. I kept researching on it for about fifteen years. We

ones that work here on Earth?

were able to take it from absolute fundamentals to f lightdemonstrat ions in space, and eventually prove its practicalI ' d s ay it 's a bou t f i f t y - f i f t y b e t w e e n s imi l ar i t ies and1

di f ferences. Robots that work in orbit, for example, can be

ac tual ut i lizat ion in space. Technology for development

big robots like cranes, ones for precise works, or free flyingof robots has reached a respectable level, but technology

robots that fly to their jobs. The crane type is built to be able

for their ut ilization is lagging behind. I want to package

to walk with its arms like an inchworm in zero gravity; themy research in conjunc tion with utilizat ion technologies,

f lying type is sort of a hybrid between a robot and a satellite.

because space robots are important tools for space activities

So there are some morphological dif ferences. There canand their utilization is indispensable. My ongoing researchalso be cons iderable internal dif ferences, even in robots

since joining RCAST has focused on two themes: utilizationthat might otherwise look quite conventional. For instanceof robots for space environment preser vation, and thewe cover them with a white insulation called beta cloth, orrecyclable/reconf igurable space system.

use solid lubricants instead of ordinary oil to lubricate parts
since oil will evaporate immediately out in space. One has

̶̶What kind of activity is "space environment preservation?"

to take var ious mea sures to enhance the reliabi lity andsafety of robots that work out in the harsh environment ofOuter space is littered with space debris, detritus from thespace, and drast ically different materials are used on themultitude of artificial objects that mankind has launched.

inside. Because it works in zero gravity, a robot that weighsThis space debris is whirling around at high speed. The big

only 100 kilograms can handle objec ts weighing ten tons orpieces alone number nearly ten thousand, and we are stilla hundred tons; t hat 's something you couldn't do here on

adding about three hundred pieces a year. If things keep up

Earth, isn't it? Control methods are different, too, because

at this rate, there is likely to be chain collisions of debris andthere aren't any stable footholds. They can take a spacewalk,

if the condition continues to worsen there is a concern that it

like the astronauts. Since their own weight isn't a hindrance,

will jeopardize future space activities. Thinking there ought

you can make robo t s t hat c ould modi f y themselve s by

to be a way to use robots to achieve coexistence between

adding another robot on the end of a robot arm or creating

the continually growing number of space satellites and thebranched elements, something you wouldn't see on Earth.

protec t ion of the space environment, I came up with theconcept of "space environment preser vation systems" and̶̶When robots l ike that go into space, are they all remotely

am currently carrying on research in that area.

controlled from the ground?
̶̶How do those robots work?
No, actually it doesn't work that way. If you try to teleoperate
through inter-satellite communication networks, for instance,

The basic concept is to care for satellite groups throughout

you get communicat ion time lags that make it very difficult

their l i ves by space robot s and not to produce debr i s .

to control by force f eedback. There a re also prob le m sSpeci f ically, I am researching on the robotization of orbit

wi th visualization and visibility, as when c amera images

maintenance vehicle, which can be launched with multiple

are degraded by t hings like s olar shadows, obst ruc t ing

satellite kits, assemble the satellites in orbit, and posit ion

objec ts, or limits on communicat ion capacity. Under thosethem in designated orbits. The robot also inspects satellites

condi tions, you run into a lot of prac t ical difficulties if youperiodically and captures them as necessary for diagnosis

try to do everything by remote control.

and maintenance to extend their life spans. Finally, at theend of the mission the robot retrieves, disassembles, and̶̶So, do you build them to work autonomously in space?

deorbits satellites. This is the lifecycle of the system that I
am working on. A nice feature of this research is that it offers

It's not realistic to make everything autonomous, so youa chance to develop nearly all of the component technologies

might say they're par tially autonomous. How autonomous

necessary for future services in orbit.

you can make them depends on the nature of the mission.
You c a n p r o b a b l y g e t t h i ng s d o n e a u t o n o m o u s l y i f

̶̶ Was it not anticipated at the outset of space development

the m i s s ion is s imple enough, bu t t ha t is di f f i cul t tothat a lot of "debris" would be generated in outer space?

do on a c om p l i c a t e d m i s s i o n .

You ha v e t o aug mentwith t e le oper a t ion what you can't accomplish throughWell, there was more or less a tendency back then to look at

autonomous opera tion. What's impor tant is to get thea lot of things as being disposable. Beyond that, though, theteleoperation and the autonomous operation to cooperate,

fact was that it would have cost a lot of money to manage

which means getting humans and robot s to cooperate andevery part that separated and dri f ted off after launch or towork efficiently by coordinating their intelligence and skills;

recover every satellite that failed. Nevertheless, the problem

we've been doing the research on teleroboti cs and space

is now coming into close focus because of recent accidents

demonstrat ions to f ind a way to realize that.

and reported near-misses involving space debris.

" Spa c e E nv i r o n m e n t Pr es e r v a t i o n " a n d"Recyclable Space System" Mainstays of FutureSpace Development

If we cont inue to leave things the way they are, for instancewhen someday space tourism really gets going, there could
be some very dangerous situations. The average speed ofa piece of space debris is ten kilometers per second. For̶̶You joined RCAST in 2002. Is your current mission aexample, there are tiny part icles of metal embedded in thedeparture from the extension of your previous research?

paint coat ing on equipment in space to improve thermalconductivity. If some of this coat ing comes off and one ofI wanted to study space robots from the very basics all thethese half-millimeter particles hits a window on the space

way to space experiment s, and beyond - linking them toshut t le, it can cause a crack; so there's a high probability2th at it would also penetrate the space suit on a personthat a robot actually becomes operational.

engaging in extravehicular act ivi ty.
̶̶What types of specialist currently form the mainstay of
̶̶It's a task for humanity, just like trash pollution in thespace research?

oceans and the industrial waste problem, isn't it? Is researchon space environment preservation something that's going

Since we can't very well call them space robots if they won't

on only in Japan, or are you collaborating internationally?

work in space, space-robot hardware technology has been
the main emphas is up unt i l now. Star t ing with materials

Right now I'm work ing on it alone, but t here's global

and mechanisms capable of withstanding ultra-high vacuum,awareness of t he problem and research is now going onheat, and radiation, we've been s tudying mot ion control

in places l ike Europe and t he Uni ted States that includes

technology for robots in zero gravity and remote control

satel lite rescue with robot s, so I imagine t here will betechnology for robots in ultra-remote environments. The

increas ing collaboration in the future.

general direction of our work here at RCAST is now shif tingtoward "intelligence" technologies, such as those required̶̶We've been talking about the space environment so

for autonomous execut ion of prec ise tasks based on thefar, but could you also say something about the subject ofdesigner's intent i ons, even in uncer t ain c ondi t ions, and"recyclable space systems"?

for diagnosis of equipment status in space by robots. We
are now in a phase where the researchers wor king in theThis is an extension on the theme of "space env ironment

art ificial intelligence (AI) are taking center stage.

preser vat ion". People are looking forward to the realizationof a recycling society based on sustainable development here̶̶Specifically, what kind of research are the students inon earth, too, but the extremely high costs of transportation

your laboratory doing?

in space make it even more cr i t ical that we evolve from the"disposable" model toward the "recyclable/reconfigurable"

The mission of our laboratory is to combine space systems

one, and I think robots can play a signi f icant role in thatengineer ing, space robot ics, and AI, a iming to develop

process.

new applicat ions of space technology. Our keywords are"robot izat ion and the applicat ion of AI to space systems".

As an example of the recyclable/reconf igurable system, I've

We're therefore researching the applicat ion of robot ics andproposed a concept that I call cellular satellites. A cellular

AI to space in a broad sense, and our students are working

satellite would be one made up of discrete cells or elements

w i th s uch s u b j ec t s as d i a gnos i s of sate l l i tes t hrou ghthat can be assembled in different ways as required for thethe applicat ion of AI technology, localization and map

s atel lite's func t ion. A failed cell could be replaced andconstruct ion of mobile robots, rotat ing mot ion estimat ion

recycled. Earth observation satellites, for instance, have a lotof mal f u nc t ion i ng s a t e l l i t es, and ac t ive d i a gno s i s ofof problems with maneuverability, flexibili ty, and operating

satellites by robots including determination of the causes ofl i f e. W i t h a c e l lul a r sa tel l i t e, you c ou l d r e a s semb l emalfunction.

observat ion systems on demand in a t imely wa y. Since
failed cells can be replaced and recycled, I'd like to think that

̶̶In others words, could we say there is research going

this idea would make maneuverable and sustainable earth

on toward even broader ranges of application throughobservat ion possible. With that in mind, I'm conduc t ing

robotization and the application of AI?

research into the cells' mechanisms and the technologies forreassembly of cells by robots.

Yes, we could. Our lecturer, Doc tor Yairi, concentrates on
the field of AI technology while my own studies are related

The Next Phase: From Research Centered onHardware Technology Toward Applications ofIntelligent Information Processing Technology

to space robots. If we divide things up ver t ically, though,it become s de t r imen t a l to s ha r ing of know led ge andinformat ion so we tend to do our teaching in cross-overfashion. We keep it f lexible: for instance one of us might

̶̶The environment in outer space is understood to be

see an interesting potential in applying AI to some aspect of

totally different from that here on earth. Are experiments

robot ics, or vice versa.

per formed primarily through computer simulations, or isthere specialized experimental apparatus?

Exchange of research information with otherfields and with industry

I'd say computer simulat ion is essent ial, of course, butinterac t ion with the external environment is very important

promotes the development of "New Ideas"

with robots and the issue is to verify how they respond to andwork within that environment. The typical process therefore

̶̶RCAST is ac t ively engaged in collaborat ive researchadvances from computer simulation to experiments withand exchange with other laboratori es. Are t here otherapparatus using terrestrial models, similar to the actuall a bor a t or i e s wi th wh i ch t he Machida Labora tory

mechanisms, in partially zero gravit y condi t ions. There iscollaborates?

gravity on earth, however, and many other environmental
condi t ions are di f ferent, so it doesn't provide complete

Of the numerous f ields of research at RCAST, AI tends to be

proof; it's only af ter technical demonstration experiments inthe one most closely integrated with the work we're doing,

space that a robot actually becomes operat ional.

so we interact regularly with "Professor Hori's AI laboratory.

3̶̶What is your opinion of the research env ironment atRCAST?
The main mission at the National Insti tute of Advanced
Indus tr ial Sc ience and Technology, where I used to work,
has turned into research toward creation of market s fortechnology since it became an independent administrative
inst itution. A unique merit of RCAST is that the emphasis
here is on new concepts, and I think that's very signif icant.
̶̶ Does y ou r g r o u p e n g a g e i n i n d u s t r y - a c a d e m i acollaborat ion
Nothing is f irm at this time, but there has been some interestin applying Japanese robot ic technologies in the aerospaceindustry. We're at the stage now where we're having study
group meet ings at which industr y representatives sit with
us to discuss the possibilities.
̶̶What sort of collaborative relationships do you have withother areas of space research, for example the "Nakasuka
laboratory?*2"
Well, of course. Our labs are like brothers, after all. When thestudents in Professor Nakasuka's lab led the development
and launch of their "nano-satellite, "CubeSat",*3" students
from our lab ac t ively par t ic ipated̶̶Have you ever wanted to go into space yourself?
I did, back when I was young (laughter). Now I'd be happy
just to see the space robots, which are my alter egos, do theirwork. Space robot s by one def inition are an extension ofhuman feelings and actions into outer space; in that sense,
they're a part of me.
(February 10, 2005)

Links
RCAST
http://www.rcast.u-tokyo.ac.jp
Machida and Yairi Laboratory
http://www.space.rcast.u-tokyo.ac.jp/index.php?lang=en*1:Professor Hori's AI laboratory.:
http://www.ai.rcast.u-tokyo.ac.jp/index.html=Professor Hori's AI laboratory.
*2:Nakasuka laboratory?:
http://www.space.t.u-tokyo.ac.jp/nlab/index-e.html=Nakasuka laboratory?
*3:nano-satellite, "CubeSat:
http://www.space.t.u-tokyo.ac.jp/cubesat/index-e.html=nano-satellite, "CubeSat

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