Q. How far has the development of BepiColombo progressed? What is the schedule for reaching Mercury?
Launch of the Soyuz rocket from the ESA launch pad. (Artist's impression) (Courtesy of ESA)
JAXA, which is responsible for the Mercury Magnetospheric Orbiter (MMO), has just completed a preliminary design review (PDR) of the orbiter, and we are now going to produce an engineering model and a thermal/structural model. Based on tests with these models, we will adjust the details of the flight model, and continue onto the production and testing stage. We have determined the design of the satellite, and are currently beginning actual production. We meet face-to-face with the ESA BepiColombo project team several times a year and exchange information on the progress of development and the problems that each team is facing.
We also hold scientific meetings about observations several times a year. Japan and Europe are each responsible for making observation plans for their own orbiters, but we need to coordinate our plans so that the two units are working in concert and performing corresponding observations. By sharing knowledge and resources, we aim to make this mission much more significant than a simple exchange of knowledge and resources -- not just a "1+1=2" situation, but "1+1=5" or even "10." There are some things we cannot observe using a single orbiter, so it is very important for us to coordinate our observation plans. We will discuss these issues during a general meeting of scientists participating in the BepiColombo project, as part of the 5th Science Working Team meeting in September 2008, in Sendai, Japan. As communication technology becomes more advanced, we are having more video conferences and telephone meetings, but it is still very important for team members to meet in person. After all, there is no better way to communicate. Through these meetings, we are trying to deepen the teams' mutual trust and respect and to promote our project together to ensure its success.
The launch of BepiColombo is targeted for 2013. The ESA will be in charge of the launch of the orbiters, cruising between planets, injection into the orbit around Mercury and the separation of the orbiters. The MPO and MMO will be launched together on a Soyuz-2B with Fregat upper stage from the ESA's launch pad, located in French Guyana. The rocket will fly between planets, and swing by the Moon, Venus and Mercury, before reaching Mercury in 2019. After its arrival, the two orbiters will be separated and the operations will commence. Observations will be performed by these two orbiters for one Earth year.
Q. What are your hopes for observations by BepiColombo?
We would like to conduct research on the commonalities and differences between Mercury and Earth in the area of plasma physics, in order to understand what is going on in Mercury's magnetosphere. Earlier in my career, I carried out research on Earth's magnetosphere. For researchers studying the magnetosphere, Mercury and Jupiter are very interesting planets, so we are very excited to have a chance to visit Mercury. Some planets in the solar system have their own magnetic fields. As Earth's magnetic field is very solid, plasma is pushed by the magnetic field and, most of the time, is forced into specific shapes, but Jupiter has a huge magnetosphere and is controlled by plasma. Because of this, Jupiter's magnetic field can be pulled by the plasma's movements and is very changeable. Mercury, however, has a very small magnetosphere. It seems to have plasma, but we still don't know why it exists, how it is maintained, or whether what is occurring there resembles the phenomena on Earth. We would like BepiColombo to answer these questions. At the same time, once the formation process of Mercury's magnetic field becomes clear, we can expect to learn more about the formation and evolution of the planet itself.
There might be some discoveries about plasma particle acceleration, not only in Mercury's magnetosphere, but also for something leading to astrophysics. During some astronomical observations, because the targets are too far away to observe directly, we have to make theoretical assumptions from indirect observations. However, by sending probes to the planets in the solar system, we can observe them directly. In this sense, we can say that a planet like Mercury is a huge laboratory. By investigating the Hermean plasma, we hope to make significant advances in plasma physics.
Q. What is the appeal of planetary exploration?
Mercury (Courtesy of NASA)
For me, planetary exploration offers a chance to understand environments that are different from our own planet, which will lead to a better understanding of Earth. That's the main interest for me. As for Mercury, I think it is connected to Earth. It is interesting to see something on other planets that we can't see on our own planet. I suppose it is our curiosity about the unknown world, where we have never been, that is the major impetus for planetary exploration.
Hajime Hayakawa, Ph.D.
Professor, Solid Planet Science Research Group, Institute of Space and Astronautical Science, JAXA
Dr. Hayakawa received a M.Sc. from the Department of Geophysics, Graduate School of Science, the University of Tokyo in 1981, and a Ph.D. from the Graduate School of Science, the University of Tokyo in 1991. He was a research associate, then an associate professor, at the former Institute of Space and Astronautical Science (ISAS) under the Ministry of Education, Science and Culture (now part of JAXA). In 2005, Dr. Hayakawa became a full professor at ISAS/JAXA. Dr. Hayakawa participated in the development of the magnetosphere observation satellite Akebono, the Geotail satellite and the Mars Explorer Nozomi. In 2006, he was appointed project manager of the JAXA part of Mercury Exploration Mission BepiColombo. His specialty is planetary magnetospheric physics.