IPMU Interview with Takao Doi

Interviewer: Hitoshi Murayama

How does it feel to catch also physically demanding. hold of a 1.3 ton satellite? Murayama: Really! To me, Murayama: Mr. Doi, I was your spacewalk looked very very impressed when you much like a stunt. What did performed a spacewalk and you feel when you actually grabbed the Spartan satellite grabbed the satellite with your with your hands. Didn’t you hands? feel any fear when you go out Doi: It felt very light. The of the spacecraft like that? Spartan satellite weighs Doi: We feel no fear approximately 1.3 tons, about because we train repeatedly the same as a compact car. It on the ground for EVAs was approaching our space (extravehicular activities). shuttle at a speed of about However, while we are 5cm per second. Due to this working on EVAs, we are inertia, I felt a heavy weight exposing ourselves to danger, the moment we grabbed it, so we must pay great but after that, while rotating attention even to things which the satellite and adjusting its are not directly related to the position, it felt very light. assigned tasks. EVAs demand Murayama: That’s quite great concentration. They are natural according to the laws of physics, but still it’s amazing, isn’t it? Takao Doi joined the National Space Development Agency (NASDA) of Doi: It certainly was amazing. Japan - now the Japan Aerospace However, the inertia meant Exploration Agency (JAXA) - in 1985 as a payload specialist and has been there was a danger of possibly working in the Japanese manned losing control of the satellite space program since then. In 1996 NASA and NASDA selected him as if we moved it too fast. We a mission specialist He flew on the . were aware of that, of course. Columbia in 1997 and is the first Japanese astronaut Astronaut Scott and I practiced to perform an EVA (Extravehicular rotating or moving the satellite Activity, or spacewalk). In March 2008 he flew on the Space Shuttle in the same direction and with Endeavour which delivered the , the same speed. Japanese Experiment Logistics Module, Kibo Laboratory to the International Space Station. He received a Doctorate in Aerospace A fascination with space Engineering from the University of that only grows Tokyo in 1983, and a Doctorate in with visiting it Astronomy from Rice University in 2004. Murayama: I see. Now I’d like

12 IPMU News No. 3 September 2008 IPMU Interview to ask what motivated you to I was in my late thirties. become an astronaut. Murayama: I understand with astronaut Takao Doi Doi: I was interested in that you earned your Ph.D. in nature from the time I was astrophysics after you became Interviewer: Hitoshi Murayama an elementary school child. I an astronaut. was a boy who loved playing Doi: I did have various outdoors, doing things like experiences during my first fishing and collecting insects. mission, such as grabbing the I was introduced to the stars Spartan satellite. Up to that after entering junior high point, I was just interested in school. First I tried observing the universe and was enjoying sunspots, which was the it as an amateur. But I came to easiest introduction. The want to know more about the landing of Apollo on the universe as my own specialty. moon, which took place when I could afford some free time I was in the third year of junior after the mission, so I enrolled high school, strongly impressed at Rice University to study me. I remember very well the astronomy further. scene of Captain Armstrong Murayama: I found one of walking on the moon. Probably your papers from that period. I became interested in the It was about universe during this period. calibration of Murayama: Did you continue a filter for the your sky observations after Hubble Space junior high school? Telescope, Doi: Yes. Starting with the published in the sun, I gradually moved on to Astrophysical Journal. the night sky. Taking photos Doi: That was my first paper. of the sky was becoming Professor O’Dell, who had popular then, and that inspired a tremendous passion for me to also take nice photos analyzing the Orion Nebula, for myself. I was camping out agreed to be my adviser. at many palces and having a We worked together on good time. several observations and data Murayama: I understand you analyses. In fact, Bob O’Dell also discovered supernovae. was a project scientist for Doi: That came much later. I the Hubble Space Telescope, started by observing sunspots, and played a leading role in moved on to observing stars the team of scientists who with the naked eye, and then continued on with night- Hitoshi Murayama is the founding sky photography. Eventually, director of IPMU. He is a leading physicist in the field of elementary however, I became unsatisfied Interview particle theory, as well as one of the and was eager to know more young leaders of the fundamental science community He received his about the universe. I wanted . Ph.D. at the University of Tokyo in to try different things, and 1991, and was based in the United States from 1993 until his return to started to look for supernovae. the University of Tokyo in January This occurred much later, when 2008.

13 constructed the Hubble Space dynamics calculations you creating planets and life. This comes from and what it is? Telescope. Under his guidance, gained through aerospace whole process is miraculously Murayama: We have I worked on calibrating the engineering. well organized. It gave me a absolutely no answer yet. filter, with which there were Doi: Yes, I did. The shock sense of the mystery of the Doi: That’s very interesting. some problems at that time. waves are generated by the universe. This motivated me to Murayama: Of course, we Murayama: What did you interactions of the jets with look for supernovae. have formulated many scenarios, work on after that? the surrounding gas. The Murayama: Does this mean but we have not reached a Doi: I worked on the Orion knowledge of fluid dynamics that your interest in the convincing answer yet. Nebula. A large number of I acquired when I was at universe is strongly related Doi: It’s said that the new stars are being born university was very useful in to your curiosity about the percentage of dark matter in this nebula and jets are analyzing the structure of the cycles of birth and death is 23%. If so, am I correct in emerging from the region of shock waves. of stars, something like the saying that dark matter exists new-born stars. Shock waves metempsychosis of nature? in our planet system? are generated as a result of Doi: I guess so. When I first Murayama: Yes, that is Dark matter, interesting the interaction between the because we don’t came to be interested in the correct. jets and the molecular cloud. understand it universe, I wanted to go to the Doi: We launch rockets, These shock waves have Murayama: I see. Regarding moon, Mars, and other planets but we ignore the existence very complicated structures your supernova observations, and to confirm with my own of dark matter when we that are related to both the recently people have been eyes that they really exist, and calculate their orbits. I think origin and the structure of using supernovae to measure to look for life if it is there. My this is somewhat contradictory the Orion Nebula. I worked the expansion of the universe, interest then gradually shifted because the dark matter must on observing and analyzing and the amount of dark energy to the evolution and structure exert gravity. How do you these shock waves with Bob is now known quantitatively. of the universe that created life. explain this? O’Dell. These shock waves In what aspects of supernovae Murayama: I think Murayama: The effects of move as time passes. If very are you interested? tremendous progress is being dark matter can be safely precise images of the shock Doi: I was able to observe made in this area nowadays. We neglected in the case of a waves are taken, we can know supernovae that appeared now know how the universe rocket being launched from the change in their locations in relatively nearby galaxies evolved to its present state. the Earth. However, the solar after 5 years or 10 years, and such as those in the Virgo Doi: Recent astronomical system, including our Earth, is that allows us to determine Cluster, so unfortunately they research has told us about circulating around the Milky their velocities. Using Hubble had nothing to do with the things like dark matter and Way Galaxy at an extremely Space Telescope images, we expansion of the universe. dark energy, and has also high speed of 220km per were able to determine their What I was most interested in told us that the amount of second, which is only possible velocities with ten times better is the fact that heavy elements visible matter is only 4%. It because dark matter in the precision than the ground- produced inside stars spread sounds very mysterious to Milky Way Galaxy is holding based observations. through space due to the me. It’s really difficult for me the solar system together, so Murayama: I suppose explosion of supernovae, and to imagine such a world. Do actually there must be plenty you benefited a great deal these heavy elements are experts have a good idea of it around us. from the knowledge of fluid the necessary ingredients for about where the dark energy Doi: It must exist, but it

Left: Mission specialist Takao Doi (right) and Winston E. Scott (left) await the approach of the Spartan satellite to the Space Shuttle Columbia. (Courtesy of NASA/JAXA) Right: The two mission specialists successfully grab the Spartan satellite manually. Takao Doi (right) and Winston E. Scott (left). (Courtesy of NASA/JAXA) (Images captured from video)

14 IPMU News No. 3 September 2008 is invisible. That’s quite a for this scientific research in research? example, elementary school mystery! space? Doi: Keeping up both roles children may not have enough Murayama: Dark matter Doi: Well, let me see. One is difficult. Astronauts are money to buy a telescope freely penetrates our bodies; it thing is the space experiments. assigned to a specific mission even if we talk about the easily penetrates rocks to reach With the completion of the about one to one and a universe. Becoming familiar underground, and on rare Kibo laboratory, which can half years in advance. Once with nature in an easier way, occasions it may collide with provide Japanese scientists assigned, we must devote like collecting insects, may be a detector which is located with good data on the ourselves to the mission and more appropriate for them. there. IPMU is planning such an characteristics of outer space we must give up working on Murayama: Certainly I didn’t experiment. If we are lucky, we in a short time and economical our own research completely. have any money to buy a may see 2 or 3 such collisions way, we will soon see good Even when we are not telescope when I was a kid. per year. We are hoping to achievements in life science, assigned to a specific mission, Doi: In my case, I was able to confirm the presence of dark material experiments, and we must go through regular buy a telescope with my own matter in this way. various experiments on training. We also have some money only after entering Doi: Do you think the best physical phenomena in space. NASA-related work, so we can junior high school. I think this guess is that they are some Japanese scientists have been only do research in our spare kind of step by step approach type of matter or elementary conducting space experiments time. I think it is difficult to is better. It would be out of particle which is as yet for nearly 20 years, but they manage both tasks. I was very balance if kids knew only about unknown to us? were forced to take too long lucky because after the first the universe. They must first Murayama: Yes, that is what a time because of the use mission NASA allowed me to learn about the Earth, nature, most of us are guessing. Of of Space Shuttle missions. have one day per week free and life. They must learn from course, we don’t know for Another thing is related to for studying at university. hands-on experience. Learning sure yet. unique features of the Kibo Murayama: Do you mean from just books is inadequate. Doi: I feel that a new view laboratory, the Exposed Facility that you got a Ph.D. degree They can expand their world of the world has emerged (EF) and the Experiment with only one day’s study per to the space around the Earth suddenly. It’s fascinating, but Logistics Module-Exposed week? or the Big Bang as they go to at the same time, it’s very Section (ELM-ES). EF provides a Doi: Yes, but I worked every junior high school and high shocking to know that the multipurpose platform where night at home until late doing school. I hope we can provide astronomy we have developed science experiments can be data analysis. good books and learning so far has been looking at launched and conducted in Murayama: That is very materials as they proceed step only 4% of the universe’s an exposed environment. We impressive. By the way, as by step. The other day, I visited constituents. Well, perhaps we can use an optical telescope scientists we are trying to the National Astronomical should say it’s“ interesting” and an X-ray telescope, as well attract young people to Observatory and, for the first rather than“ shocking”. as an instrument that allow science in various ways. Please time, saw a three dimensional Murayama: It’s extremely constant monitoring of the tell me your thoughts about movie about the solar system interesting. I really hope to pin Earth’s ozone layer. We can how we can attract young and clusters of galaxies in the this down. put a telescope like the Hubble people to science and, in universe. We now have places Doi: Well, good luck to you. Space Telescope in a manned particular, to the study of the such as this where we can facility. The strongest feature universe? have exciting experiences of Hopefully children will learn of the EF and ELM-ES is that Doi: Based on my experience the universe. about the nature around them before they study they enable frequent and when I became interested in Murayama: Yes, that movie is space easy access for replacing and science as a young boy, I think fantastic. Murayama: Scientific manipulating observational it is not advisable to start Doi: I think it would be great Interview research using the Japanese instruments. initially with subjects that are if people could see displays like “Kibo” laboratory in the Murayama: How do you too difficult, as young people that in planetariums and other Space Station will soon start. manage your life both as an may rebel against, and depart places. What do you think the most astronaut and as a scientist from, science. It is important to Murayama: I agree. Thank important direction will be undertaking your own go forward step by step. For you very much.

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