Makiko Otake of the Japan Aerospace Exploration Agency (JAXA) contributed an essay to Tohoku University about the relation between the Japanese space probe “Hayabusa” that has returned to the Earth on June 13, 2010 and Tohoku University from which she graduated.

---

 

Hayabusa and Tohoku University

Makiko Otake at Institute of Space and Astronautical Science, JAXA

 

 Some of my colleagues in the department of JAXA where I belong have been deeply involved with the Hayabusa project, although I am responsible for the lunar orbiter Kaguya, not for Hayabusa.  As a researcher with interest, I feel extraordinary enthusiasm and high sprits of those who are involved with the Hayabusa mission all the time.  Also, as a graduate of Tohoku University, please let me introduce the relation between the mission and some faculty members of the university. 
 

 

 

 Hayabusa was launched in 2003, and arrived at the asteroid Itokawa 300 million kilometers from the Earth over more than two yeas.  Hayabusa observed shapes, geography, surface temperature, reflectance spectrum, mineral composition, gravity, and major elemental composition of Itokawa from the surrounding space, and collected various data after landing on the asteroid.  A capsule containing samples flied to the Earth taking about another four and half years and landed on a desert of Australia on June 13, 2010.  Many people must be touched by that a capsule came back to the Earth where Hayabusa departed despite some troubles. 

 

 

 One of findings from Hayabusa’s observational data is that Itokawa is covered with rocks in various sizes, and that, as a whole, it is rubble piles just like a heap of bricks with some space between rocks inside.  These features verified that tiny bodies were destroyed by collision into other bodies and that resulting rubbles got together to form Itokawa.  Collision, destruction, and growth of bodies with debris have been universal phenomena in the history of the solar system.  Elemental composition on the surface shows that Itokawa was formed in the early history of the solar system to survive collisions and destructions without melting.  Largely grown bodies such as the Earth and the moon lost information as they were formed because their inside melted and differentiated.  Analysis of samples in the Hayabusa capsule is expected to provide key direct information on the asteroidal origin and the solar system’s birth.

 

 The Hayabusa project is a longtime mission that has been planned, conducted and supported by many researchers and engineers.  This is true of other planetary exploration spacecrafts, as well as Hayabusa.  I had a few chances to learn the operation of Hayabusa including sending a satellite an order and output of information.  A signal sent to Hayabusa is to check its integrity just like asking “Hello, How are you?” and the answer, which means “I’m great,” was sent back.  The signals take several dozen minutes to reach Hayabusa and to come back to the Earth at light speed, which shows such a long distance between Hayabusa and the Earth.  When imagining Hayabusa’s long journey until it come back to the Earth sound and safe, I realize that efforts of many staff members involved with the mission are immeasurable.    　　

 

 

 Faculty members at Tohoku University also play an important role in the Hayabusa mission.  Professor Kazuya Yoshida at Department of Aerospace Engineering, Graduate School of Engineering participated in the working group for evaluating sampling technologies on the asteroid from the beginning of the project.  He was also involved with the determination of the sampling method, and detailed study and verification experiment of dynamics and control simulations in each phase including letdown, landing and take-off. 

 

　　Moving image of Hayabusa touchdown simulation

　  Yoshida Laboratory Website

 

 

 

 

 

 Associate Professor Tomoki Nakamura at Graduate School of Science is engaged in analysis and study on samples from the asteroid, and distributes them to staff in charge.  He said;

  “I am honored to be able to analyze the Hayabusa capsule that came back to the Earth without damage.  If it contains dust particles of Itokawa, my mission is to find and take out from the capsule and analyze them, and to show Itokawa’s property in materials science.”

The comment of Associate Professor Tomoki Nakamura is available at “http://www.sci.tohoku.ac.jp/mediaoffce_s/naka-hayabusa.html 

  Associate Professor Nakamura is humble in his comment, but world’s scientists focus on his analysis and research results.  I would like to congratulate Hayabusa’s coming back, and expect the future results.