YANO Hajime

Prof. Hajime Yano has been actively involved in scientific research of solar system exploration with emphasis on small bodies such as asteroids and comets for 20 years. His expertise also extends to observational, experimental, analytical and theoretical works of cosmic dust and space debris as well as space missions. In particular, he has devoted a whole career for in-situ detection and collection of cosmic dust and ultimately sample return missions from their parent bodies such as Stardust and Hayabusa.

He has contributed more than 110 refereed papers as a researcher, a co-investigator, or the principal investigator of more than 10 past or on-going space projects from Japan, Europe and the United States including LDEF, EuReCa, HST, SFU, Nozomi, Stardust, Hayabusa, Leonid-MAC, SSSAT, IKAROS, Tanpopo, BeiColombo, Tanpopo-2, EQUULEUS, Hayabusa-2 and OKEANOS. Among them, he has accomplished a number of pioneering works that led major scientific discoveries or/and “game changing” movements in the solar system exploration.

In the space shuttle era, Prof. Yano has established post flight analysis procedures of micrometeoroid and orbital debris impact signatures on retrieved spacecraft surfaces. Several hundred impacts per spacecraft such as LDEF, EuReCa, and HST were revealed their origins and formed fundamental database for dust environment modeling in the near Earth space. The SFU post flight analysis formed Japan’s first in-situ measurement database of meteoroids and debris.

In 1998-2002, Prof. Yano and his team became the world’s first to use high definition video imagery for astronomical research and their airborne observation onboard the Leonid MAC mission yielded both the faintest influx and organic and volatile spectroscopy of the Leonid meteor storm, a rare astronomical event in every 33 years, that had allowed a quantum leap of meteor science as a “human mission to comets without going to space, by using the atmosphere as a large dust detector”.

Prof. Yano developed and operated a number of new instruments for cosmic dust detection and collection. The detectors include the Nozomi-MDC impact induced plasma detector, the BepiColombo-MDM acoustic sensor, and the ALADDIN PVDF detector onboard SSSAT, IKAROS and OKEANOS as well as the CLOTH PVDF integrated within MLI thermal blankets. All of them are involved in hypervelocity impact calibration experiments and simulations so that Prof. Yano developed stable shot gun techniques for microparticle impacts with two stage light gas guns at University of Kent in U.K., NASA Johnson Space Center in U.S.A. and ISAS in Japan. ALADDIN onboard the world’s first interplanetary solar sail IKAROS deployed 0.54 m2 detection area of cosmic dust impacts; it is the largest, dedicated dust detector in the history of the solar system exploration and has yielded the finest structure of dust distribution ever between the Earth and Venus.

Intact capture of meteoroids was attempted by foil stuck or aerogel modules used on LDEF, EuReCa, Stardust, Tanpopo and Tanpopo-2. Prof. Yano was also involved in development of an ice melting dust collection device for Japan’s first Antarctic micrometeorite expedition in 1999. He is now advancing these experiences for future mission concepts like the solar power sail to Jupiter Trojan asteroids and a sample return mission from Enceladus’ icy plume.

Also noted is Hayabusa’s asteroid surface sampling device that resulted on the world’s first asteroid sample return in 2010. This impact sampling technique that Prof. Yano and his team developed is a robust system suitable for almost any unknown surface conditions of an airless solid body. This technology is now inherited to Hayabusa-2 mission and other sample return missions consider it as a reference. Upon the sampling attempt on Itokawa, Prof. Yano and his colleagues discovered evidences of granular migration on such a small body, which revolutionized ideas of their surface activities and created a new research field of “microgravity geology”. As future sample return missions are more inclined to organic and volatile rich small bodies, he is also contributing in the fields of astrobiology, planetary protection and microgravity experiments.

In international academic arena, Prof. Yano has served leading positions for organizing numerous scientific meetings in the collaboration with COSPAR, IAU, ISTS, and space agencies. He was the chair of the inaugural meeting of the International Primitive Body Exploration Working Group (IPEWG) that attracts space agencies for international collaboration and co-ordination in the solar system small body missions from 2008 till present. At present, he is the Academician of the International Academy of Astronautics (IAA) and served as the first Japanese Associate Editor of the international refereed journal "Advances in Space Reseacrh".

As an educator, Prof. Yano has given a number of guest/invited lectures in universities and institutes worldwide. In Japan, he has also supervised a number of Masters, Ph.D. students and international interns in the field of solar system science and exploration at ISAS.