JAXA Japan Aerospace Exploration Agency

Q. What made the biggest impression on you when you look back at the seven-year journey of HAYABUSA?

Asteroid Itokawa

It may sound a bit obvious, but I remember well the arrival and landing on the asteroid Itokawa, the rescue of the lost HAYABUSA, the urgent repairs to the ion engines that allowed it to continue to operate, and in particular, the safe return to Earth.
We got a clear view of the surface of Itokawa only on the day of arrival. Previously, we could tell that the asteroid was peanut-shaped, but the detailed topography of the rocky surface was not known. We had presumed that the surface was covered with regolith [sand] and that there were craters on it, so I was very surprised when I saw surface details on Itokawa that were unexpected. And I was full of joy that we seized the chance to be the first humans to see this asteroid up close.
The main reason we were able to continue operation of the ion engines was that no matter what crisis arose, no one gave up. Everyone kept striving for new ideas and solutions. The project staff were highly motivated, and their determination is reflected in the results - that’s also very memorable for me. I believe their determination is a testament to how fascinated everyone was by the HAYABUSA mission.

Q. HAYABUSA went through many difficulties, including instrument malfunctions. As the project manager, was there anything you paid special attention to?

Prof. Kawaguchi and his colleagues in the control room, watching the return of HAYABUSA

My title was project manager, but I barely recall managing in a traditional way. As I said earlier, everyone on the project team was highly motivated, so they all worked proactively without waiting for instructions. No matter what kind of crisis challenged them, each of them gave their best effort. However, if I were to say, I tried to create an atmosphere to make it easier for everyone to contribute ideas. I wanted to take in good ideas regardless of people’s prior achievement or status. For instance, when an untried new method was proposed, if I thought that it was the best idea, I adopted it instead of turning it down because of the risk.

Q. What does HAYABUSA mean to you?

Asteroid explorer HAYABUSA

HAYABUSA was like my child. An explorer is basically a machine that has had a program loaded onto it. But the program is never finished - after launch, it is frequently rewritten or added to. Program here means a set of rules to tell it what to do in certain circumstances. So to revise the program is to teach the explorer a new rule each time. This process really feels similar to bringing up a child.
Asteroid Itokawa is more than three hundred million kilometers away from Earth, and it takes 35 minutes for a command to reach the explorer via radio waves and a response to reach us in return. So we gave HAYABUSA the ability to navigate autonomously. Just after launch, HAYABUSA was controlled entirely from the control room on the ground, but as the rules were rewritten, it started learning to operate during cruise and navigate in proximity stay by itself. In other words, HAYABUSA learned to determine its own location and the proper direction to fly in while it descends for touching-down. Every time we revised the program, HAYABUSA learned something new and became more independent. To me, it was like a child I had brought up doing its best to try to accomplish what it was taught.

Q. How would you like to further develop what has been acquired through the HAYABUSA mission?

The last image of Earth taken by HAYABUSA. After this, it re-entered the atmosphere and burned up.

First of all, we need to continue sample-return exploration missions. We were lucky enough to be able to bring HAYABUSA home, but improving the reliability is an important next step to establish the technology ahead of the rest of the world. In the meantime, of course, I think the real goal is to return samples from another celestial body, so I would like to achieve this with HAYABUSA 2, which is now under review. We can attempt this thanks to our success with HAYABUSA.
And although the HAYABUSA spacecraft itself burned up during re-entry, I would like to keep the next one alive: instead of having HAYABUSA 2 re-enter, I would like to try to moor it at a Lagrangian point between the Sun and the Earth. A Lagrangian point is a position where the force of gravity between the Sun and the Earth is balanced out. I’d like to conduct such a flight demonstration so that one day a deep space port can be built as a kind of home port for cruising the solar system. The idea behind this is to use the space port as a base, and reuse a spacecraft or spaceship such as HAYABUSA many times. People might find the concept unrealistic, but when we started the HAYABUSA mission, I am confident every technology required is ready for the Deep Space Port operation. I hope the day will come, 20 or 30 years after the expedition, when people will pick up HAYABUSA 2 and bring it home.
There are always risks in conducting missions that have never been attempted before, such as we saw with HAYABUSA. However, even if there are risks, it is very important to continue to develop new technology and use it in space exploration. This is something that applies overall to science and technology, but in the case of space missions, it takes 10 or 20 years from developing a concept to achieving results. In fact, the concept for HAYABUSA came up in 1980s. It is wrong to invest only in short-term agendas just because a long-term mission takes too long to bring results. It may take time to achieve results, but when you keep at it, achievements eventually start occurring every year. I believe that continually working on long-term projects leads to the passing on of knowledge and technology. And it will give confidence and hope to the Japanese people, which will be a driving force for providing a positive view of the future.

Q. What are you expectations for future planetary exploration by Japan?

Asteroid explorer HAYABUSA 2 (courtesy: Akihiro Ikeshita)

Planetary exploration has not only a scientific purpose; it can inspire interest in science and in other celestial bodies. Science derives from curiosity, so the mysteries and wonderment of planetary exploration can be an important catalyst for young people to develop that curiosity. Also, gaining new knowledge contributes to the growth and development of culture. I think planetary exploration not only helps advance science and technology, but also enhances the public’s interest in science, and helps educate the next generation.

Q. What advice do you have for young people?

I want them to get interested in something, and most importantly, I want them to have the right attitude to take on new challenges. The world is filled with mysteries and wonders, but what to study is up to each person. Many questions might have already been answered, but that’s beside the point. What counts is having questions yourself.
Having a vision is also important. To make a new discovery, I think you need to have a dream - an immense idea. As long as you study only what the textbook tells you, you will probably not be able to do more than what is written there. I would like young people to be curious, and to try new things that are not in textbooks. For example, the primary objective of the HAYABUSA mission was to return samples from another celestial body - something completely new. But in a way, it was something that anyone could dream of doing.

Q. What is your goal or dream now?

Small Solar Sail Demonstrator IKAROS

I’d like to establish a route for solar-system flight. To do so, I am thinking of projects that could serve as steps towards building a deep space port at a Lagrangian point between the Sun and the Earth, and exploring the vicinity of Jupiter using a solar sail. The small solar sail demonstrator IKAROS, which was launched last May, was the first such spacecraft to achieve orbit control. To explore the area around Jupiter, we have a project to use a solar sail to observe Trojan asteroids situated at a Lagrangian point of Jupiter. By investigating Trojan asteroids, we may be able to learn new things about the origin of life on Earth and the birth of gas giant planets such as Jupiter.
HAYABUSA’s return was indeed our ultimate joy. I would like to continue to launch space missions that will inspire people to dream, just like the HAYABUSA mission did for us.