Kozo Otani, operations planning support software development and operations engineer, NEC Aerospace Systems

AKATSUKI's five on-board cameras will capture images of Venus by using a variety of modes. To control these cameras, new operations planning support software was introduced for AKATSUKI.

When development started, two people were in charge: Masafumi Kimura (described in the highlighted article below) and Kozo Otani. However, Masafumi Kimura, a veteran with years of experience, died suddenly during development. "What would Mr. Kimura have done?" Mr. Otani asked himself, relying on the support of those around him as he followed in his mentor's footsteps to finish the system.

- You helped develop the operations support software and are currently using the software as a member of the AKATSUKI operations team. What can you tell me about the software?

Concerning the software PCNAV, the PC in the name refers to the AKATSUKI project name PLANET-C. When you enter what sorts of operations you want to perform into the software, the software automatically judges various conditions and eventually outputs the commands to send to the probe.

- Can you explain the software in a little more detail?

Otani: These are the PCNAV windows. Information related to operations is arranged in an intuitive and easy-to-understand way. The center shows the waxing and waning of Venus and its apparent size. This window also shows where in the orbit the probe is.

PCNAV operation windows

As an example, the user might enter a request to perform observations at a certain time. The software then analyzes judgment conditions such as the direction of the Sun and Earth, the direction of the shadow of Venus, the angle of the orbit around Venus, and the period of time during which communication between AKATSUKI and the Usuda Deep Space Center (UDSC) is possible.

The software then uses the conditions to judge whether the entered request can be safely carried out, and then returns a result indicating that the request can be carried out or that there is a problem. Next, the software creates an operations plan consisting of a series of steps for safely carrying out the request and then outputs commands that can be directly sent to the probe.

- So, the software can only be used after AKATSUKI enters the orbit around Venus?

Otani: No, the software was designed so that it can output operations plans even during AKATSUKI's trip to Venus because several observations were planned for. For example, during the last third of October, the probe captured images of the ecliptic plane to observe zodiacal light.

- It seems like coordinating all of this would have been difficult for just one person. Have you always been involved in this field?

Otani: No, actually. I spent my time in college researching probe orbit determination at the National Aerospace Laboratory of Japan (NAL), which is now known as the Japan Aerospace Exploration Agency (JAXA) Chofu Aerospace Center (CAC). I researched methods for calculating where and how a probe is flying in the Solar System based on data received on the ground. I started working at NEC Aerospace Systems because I wanted to do this sort of work, but I initially worked in a different division for four and a half years. Luckily, I was eventually recommended due to my research of orbit determination and was moved to my current division in 2004.

After that, I was involved in the lunar orbit explorer Kaguya and started participating in the AKATSUKI project in 2008.

- Was the development of PCNAV Mr. Kimura's idea?

- So you're saying that developing the software was a coordinated effort?

Otani: Mr. Kimura was a really exceptional engineer. He freely used equations and calculations as though he were using nothing more complicated than scissors and glue. Not only that, but he had tons of experience. He was involved in probe operations from the time that Japan first launched Sakigake and Suisei into the Solar System, and, even though we failed to enter the orbit of Mars, he was instrumental in leading the orbit operations as the Mars explorer Nozomi struggled towards Mars. (This is described in detail in Shinya Matsuura's "Terrible journey: Mars "Nozomi" took in 12 years".) In other words, Mr. Kimura had loads of the sort of know-how that can only be acquired through life-and-death experiences on the field of battle.

Mr. Kimura applied the know-how he gained during his work to PCNAV to help reduce the possibility of mistakes. As I only had experience with the Kaguya operations, I learned a lot from him.

However, in August 2009, Mr. Kimura died of a sudden illness. The death was so sudden that no one could really believe he was gone.

At that time, we did not even have the complete specifications in document form. I'm sure that Mr. Kimura's head was just full of ideas for how to go about finishing the PCNAV software. Unfortunately, he died before all of the specifications could be documented.

I ended up having to finish developing PCNAV on my own. Every day was a struggle and a series of trials and errors. I found myself constantly wishing that Mr. Kimura was still around. In the end, I only managed to finish the software thanks to the support of Mr. Oshima, the project manager, and many other co-workers.

- How did you continue to develop the software after Mr. Kimura died?

Otani: I talked to people related to the project to gain a clear understanding of the user needs. For example, each of the five on-board cameras has a different observation target, person in charge, and operation requirements. I talked to space research professor Takeshi Imamura (an AKATSUKI project scientist), asked about camera-related needs, and eventually put together a list of several patterns for using the cameras in combination while in the orbit around Venus. I then set up the software so that a user could create an operations plan by selecting the pattern to use.

As the launch date approached, various specific user requirements for the software became apparent. I found out about these needs, determined which ones were feasible, and continued working to develop the specifications.

I continue to do this work even now. One aspect of software is that it must be corrected to match changing conditions even as it is used. I suspect that, when the actual observations of Venus begin, there will be more new requirements. If so, PCNAV will probably have to be upgraded even more. My goal is to ensure that the software is reliable and makes it possible to do what those in charge of operations want to do.

- What do you want to do next?

Otani: During my most recent work, I helped develop the software for AKATSUKI, which is bound for Venus, an inner planet, but I want to modify the software so that it can also be used for outer planets. Operations support software similar to PCNAV will probably also be required for the successor to Hayabusa. When we travel further into the Solar System, I suspect that we will need yet another new system. I'm looking forward to that.

On the fourth floor in a certain building at the NEC Fuchu Plant, there is a desk that lost its owner. A file on which "PLANET-C -PCNAV" is written remains there. Standing in front of that desk, Otani realized that he had inherited Kimura's dreams of planetary exploration.

"I think I achieved most of what Mr. Kimura planned."
Following Kimura's sudden death, Otani tried to do what he thought Kimura would have as he worked on AKATSUKI. Perhaps, even now, he can see his mentor ahead of him, pushing ever forward.

Researched and written by Shinya Matsuura, October 27, 2010

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