By Tom Risen|October 2018
This month’s scheduled launch of the two BepiColombo orbiters to Mercury will be personally significant for Hiroshi Yamakawa, president of JAXA, the Japan Aerospace Exploration Agency. During the planning phase of the mission in the early 2000s, he was the project manager at JAXA for the country’s contribution to this joint mission with the European Space Agency. After a stint in academia and advising the prime minister’s Cabinet, Yamakawa returned to JAXA in April in time for the launch of BepiColombo and receipt of the first images from Hayabusa-2, a probe now orbiting the asteroid Ryugu in preparation for landing on it. In the aviation realm, Yamakawa arrives as JAXA is planning additional research into quiet supersonic aircraft and continuing work on a laser technology for detecting turbulence ahead of passenger planes, among other endeavors. Yamakawa is the fourth president of JAXA, which was formed in 2003 from the merger of three space and aviation organizations. He is the first president to come from academia rather than the business world. Yamakawa spoke with me by phone from JAXA headquarters in Tokyo.
IN HIS WORDS
There’re lots and lots of mysteries about Mercury because of its size, the existence of magnetosphere, the existence of the very thin atmosphere. Planetary scientists cannot explain everything at the same time. I think it’s because of the lack of information. Observing Mercury provides the information and some clues to the formation of planets, including Earth.
It is easy for us to presume its core has already cooled and solidified. Mysteries still remain as to how Mercury was formed and why this is the smallest planet in our solar system that seems to hold a molten core. JAXA will try to better understand those mysteries through geological research and observations of its magnetic field to be obtained by the Mercury Magnetospheric Orbiter and the European Mercury Planetary Orbiter spacecraft.
Defending against asteroids
To tackle hazardous asteroids approaching the Earth, the first step is observation to determine the orbit precisely. That enables us to estimate the collision probability and the time frame. The next step is to change the asteroid orbit well beforehand. If we discover asteroids which may hit Earth, for example, in 20 years, we would have to launch a spacecraft to impact the asteroid 10 years before it hits Earth.
Sampling an asteroid
We believe the asteroid Ryugu contains water and organic matter. The Hayabusa-2 mission to collect the underground material from 4.6 billion years ago in that crater thus explores the origins of sea water and of life on Earth. Remote observation of Ryugu will first be done to make a map of the asteroid including the gravity and geological distribution.
I think a logical step forward is to orbit and explore a different type of asteroid at a different place. Like those asteroids between Mars and Jupiter, for example. The technologies which enable us to create an artificial crater on the asteroid can be utilized for missions and, of course, private companies can utilize it for their own business.
Supersonic speed limits
In the D-SEND [Drop test for Simplified Evaluation of Non-symmetrically Distributed sonic boom] project, which is already finished, JAXA ran the world’s first low-boom supersonic technology test flight [dropping the supersonic glider from a stratospheric balloon]. As a result, I would say the noise level of a small supersonic passenger plane — equivalent to thunder sounds — has been brought down to a door knock. That was a tremendous reduction of noise and this is, dare I say, significant enough to activate international standardization of low-boom supersonic standards in the United Nations International Civil Aviation Organization.
Designing a supersonic passenger jet
JAXA will expand the D-SEND low-boom technology to include the aircraft and engine for a supersonic passenger plane. That kind of project is maybe the next step, but is not yet funded, so it’s still at the research level. There are lots of JAXA researchers engaged in supersonic technologies.
Flight tests of the JAXA Turbulence Detection System were conducted on the Boeing ecoDemonstrator this year. Data analysis is still underway. JAXA and Mitsubishi Electric Corp., the manufacturer, seek to [make an operational version for passenger aircraft]. A standardization process is vital.
Partners to the moon
We’re discussing lunar exploration with the international community. China is a member of that working group, not only Europe and the United States. Right now, we are discussing what JAXA can contribute to the [NASA Lunar Orbital Platform-Gateway]. JAXA has its own lunar exploration study framework and our high-precision lunar landing mission called [Smart Lander for Investigating the Moon]. Our next step is the observation of the lunar pole region resources.
View on climate change
I think global warming is a common challenge for everybody. I’m talking about humankind. The impact that global warming poses — the sea level rise is just one aspect of it — is far more serious than what Japan, or any other single country can deal with. In order to contribute to the Paris Agreement, Japan has set goals to reduce greenhouse gases.
Satellites and greenhouse gases
Japan spearheaded satellite-based greenhouse gases monitoring in 2009, when the [Greenhouse Gases Observing Satellite, or GOSAT] observation satellite was launched. Satellite observations are very effective to monitor greenhouse gases because they can provide extensive data. I will be pleased if Japanese satellite observation technology contributes to the world as well as the Paris Agreement.
Outreach with China on Earth science data
There’s no direct collaboration now. We’re collaborating with every country in the world that is interested and especially talking about greenhouse gases. Environment data from satellites is an asset that belongs to the global science community. Our data is shared through the international framework Group on Earth Observations and the other framework is Committee on Earth Observation Satellites.