Japan's Missions to Primitive Bodies in the solar system: from Hayabusa to Marco Polo

Paper number

IAC-08.A3.5.5

Author

Dr. Makoto Yoshikawa, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Hajime Yano, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Junichiro Kawaguchi, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Abe Masanao, Japan Aerospace Exploration Agency (JAXA), Japan

Year

2008

Abstract

By Hayabusa spacecraft, for the first time, we saw the real appearance of a very small solar system body, asteroid Itokawa, whose size is only about 500 m in length. We had a lot of scientific results form the observation of Hayabusa, and we got many clues to know the origin and evolution of such small bodies. The most significant thing is that the density is 1.9 g per cubic-centimeter, although the surface material seems to be the ordinary chondrite. We think that the inside structure should be a rubble pile. Hayabusa is now on the way to the earth and it will come back to the earth in June 2010.

As working for Hayabusa, we have been considering post-Hayabusa missions. Since the Itokawa is an S-type asteroid, next target should be a C-type, because these two types are abundant in the main asteroid belt. The next mission is called 'Hayabusa-2,' which will explore C-type asteroid. The spacecraft is quite similar to Hayabusa, so we can save time for manufacturing it. The current target asteroid of Hayabusa-2 is 1999 JU3, which is intensively observed in 2007 and 2008. At the same time, we also consider much more advanced mission after Hayabusa-2, and this mission is called 'Hayabusa-Mk2.' The target of Hayabusa-Mk2 should be much more primitive objects such as P or D-type asteroids, CAT, comets. The spacecraft of Hayabusa-Mk2 is a newly developed one. In this way, we (=JAXA) are considering programmatic missions for the exploration of primitive bodies. Since there are many small bodies in the solar system, we should have such strategic approach.

From 2006, Hayabusa-Mk2 is also considered under the scheme of Cosmic Vision of ESA with the European study group for small bodies of the solar system. And it was proposed to Cosmic Vision with the name of 'Marco Polo.' It has passed the first selection so now we are in the assessment phase. The spacecraft, for which Japan is responsible, is based on the idea of Hayabusa-Mk2, but we reconsider it to have a large lander and a new sampling system from Europe. 

We hope that both Hayabusa-2 and Marco Polo will be realized in the future under the collaborations with many countries. We also hope that we will get the clues to solve the mysteries of the birth and evolution of the solar system and the life.

Abstract document

IAC-08.A3.5.5.pdf

Manuscript document

IAC-08.A3.5.5.pdf (🔒 authorized access only).

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