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The Forefront of Space Science

Solid Rocket Research Challenge: World's number one in the past and worlds' number one in the future
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Innovation of launch system - pursuing next-generation technology

Another important aspect is the establishment of a next-generation launch system. In other words, a scheme where we can launch small satellites one after another. Ideas to realize this include improving efficiency in launch operations, such as rocket assembly and checkups, and optimizing lead time and manpower necessary for launch preparation by making ground inspection and test facilities compact. The key is in the innovation of avionics as well as a newly designed rocket structure enabling easy rocket operation.

For the next solid rocket, we plan to create information networking of avionics by linking them with a high-speed serial bus as well as making the rocket more intelligent so that it can perform very complicated checks autonomously before the launch. Although the term “autonomous checkup” sounds impressive, it is not unusual in other industries. The automatic checking of a car’s airbag system is a good example. Mechanism of airbag works on the principle that when a car senses shock, explosive ignites to generate gas to expand the airbag. Automobiles use a similar ignition system as rockets. The important point is the timing of the airbag check: it is not completed in the factory, but tested automatically every time the engine is started. The engine can start only when no fault is detected. The rocket ignition system check requires high safety, and demands great manpower and time even if the check is a very simple one such as the connection of a check-up cable. In the future launch system, such tests will be performed immediately by remote control.

In addition to the ignition system test, the future system will also test autonomously other payload systems. Accordingly, a number of complex devices and facilities occupying rocket control room will no longer be required. Rocket control in the future will be as simple as one laptop PC (Fig. 3). In order to expand the flexibility of the checks, we plan to devise a mechanism to perform detailed manual checks inside the payload systems using the vehicle’s network function. We said before that we aimed to make rocket control as compact as possible to relocate it easily. Currently, rocket control will likely be advanced far beyond such old ideas. It might be compact enough to fit in our hands. We will call it mobile control. It is forecasted that this dreamlike launch system will become a standard of next-generation rocket technology in both liquid and solid rockets. Such a system is indispensable for us to maintain the world’s state-of-the-art technology in space-transportation systems.

Our intention is to make rocket launch as easy as a daily activity. I expect that future rockets will be a system that flies every week like Thunderbirds. The next solid rocket is the first important step toward such a futuristic rocket.

Figure 3
Figure 3. Control concept for the next-generation rocket at launch.


More than one year has passed since the last M-V rocket launched the solar-observation satellite HINODE. With progress in research over the period, the concept of the next solid rocket has become very clear. Our goals are a low-cost rocket with high-performance comparable to the M-V and innovations in the launch system to pave the way for the next generation. Of course, the next solid rocket will be very user-friendly. We are also continuing research on the relaxation of the severe payload environment peculiar to solid rockets. Moreover, we are exploring the possibility of introducing a velocity-adjusting stage carrying a small liquid engine in order to improve accuracy in orbit injection.

With these advances, the wheel of history of solid rocket research originally promoted in Japan will roll forward much more stronger than ever. We must have an outstanding rocket to be qualified as a successor to the world’s number one, the M-V rocket.

(Yasuhiro MORITA)