Technology

Research Director Dr. Hironori Sahara

Dr. Hironori Sahara

Faculty of System Design, Tokyo Metropolitan University
Professor, Division of Aerospace Engineering

Seems like some strong talents are joining the team
I believe so. I was more than excited to learn that Dr. Abe is joining: he is an expert on shooting stars. This is because of the media coverage that Dr. Okajima has been receiving lately; I would not have met Dr. Abe had I been working alone on this project.

What was your first impression of Dr. Okajima?
I thought she was very approachable. I had been in contact with her since Axcelspace approached me, but I only met her three years later. We got along really well since the very beginning: it felt as though we have known each other for a very long time.

What are the difficulties associated with technical development?
Ensuring accuracy and reproducibility, since for artificial shooting stars to function as a form of entertainment, the audience needs to be able to see the shooting star in their sight. There's no use being able to see it in Washington when we aimed for New York for example.
I am not too concerned about attitude control, but I need to be very careful when it comes to discharging the particle. It is possible for the shooting star to appear hundreds of kilometers apart with just 1% difference in the speed of the satellite. The path of the shooting star also changes with the angle of discharge, atmospheric condition and density.
I believe the key to success is to ensure that the shooting star appears within an acceptable range of error. My simulations play a very important role to this end. In my perspective, it is also imperative that the software and the hardware work together seamlessly. It is very common for the combination to not work properly despite the fact that the individual components are working perfectly as a standalone.

Sounds very tough. Will you make it for the service launch in 2017?
Yes, definitely.
A prototype simulator is already functional. Within the next year, in 2016, an official version will begin servicing which will account for many more parameters, such as the sunspot, and simultaneously calculating probabilities of colliding with debris.
In terms of the technical aspect, we have a clear prospect on the particle source, and there are many hardware issues that can be solved financially.
Researchers like myself often try to solve a problem by improving upon a device at hand. We love tinkering.
However, if you look around the world of technical development, a persistent problem a bulb that costs 20000 yen/piece could not solve maybe be easily solved with a bulb at 2000000 yen/piece. We are very fortunate to know which technical aspect can be solved by trial-and-error and which aspects can be solved with finance. On top of it all, ALE has attracted a lot of interest from a variety of fields, as a very innovative aerospace business.