Impact Objectives

• Investigate designs for innovative high performance and low-cost solid rocket fuel

• Demonstrate the use of the low-melting point propellant in a practical setting

• Develop further improvements to the full-scale rocket-grade solid fuel

Fuelling rocket launching success

Dr Yasuhiro Morita leads a team that is revolutionising the space rocket industry with its low cost, high performance solid rocket fuel

What research is satellite launches, ultimately invigorating its puncture-proof tyres of bicycles. The underway by your the space industry as a whole. We also company’s knowledge in its field is essential department at the want to make the same low-cost solid fuel in our current research on low-melting Institute of Space available for model rockets, with the goal point solid rocket fuel resin. Uematsu has and Astronautical of promoting scientific education to the experience in developing and using small- Science at JAXA? younger generation. scale hybrid rockets, and is our trusted partner in developing demonstration At the Institute, we What did you learn from your recent rockets and conducting static firing tests primarily focus on the development and demonstration flight? and launch procedures. HASTIC has been scientific research of challenges related to vital in fostering good relations with Taiki, spacecraft, such as satellites and planetary The flight has helped us demonstrate the in Hokkaido, where we have our launch site. probes, and their launch methods (space ability to significantly increase the efficiency To upscale the development, contributions rockets). One example of the former are the of rocket production. We have shown that of IA and NOF are inevitable with their missions of Hayabusa 2, the asteroid probe even as a model rocket-grade solid fuel, the experiences in full-scale solid fuel rockets scheduled to return to Earth in December low-melting point propellant is practically like Epsilon. 2020 with samples from its mission. We usable. Previously, it had taken us several have also been involved in SLIM, which months to produce and prepare the fuel, What results have you seen from your involves a small-scale lunar explorer, and but in our latest launch, we were able to launch tests so far? the MMX, which aims to provide a return complete this in around four hours. I believe sample from one of the two moons of that this is one of the biggest innovations so Radically reducing the cost of building a Mars. As for the launch methods, various far achieved in solid fuel rockets research! rocket is the primary goal of our work. Our research projects, such as the development We now hope to apply this to larger scale launch tests have proven most satisfactorily of Epsilon’s guidance system and small-scale rockets such as our Epsilon Launch Vehicle. that a significant increase in efficiency is reusable rockets, are underway. possible in new generations of rockets. In Can you talk about the importance of addition, the fact that our model rocket One of your projects involves research on collaborative relationships? grade rated, low-melting point fuel is innovative high performance and low-cost already practically usable is very significant. solid rocket fuel. What are your goals for To further push space development and Currently, model rockets for educational this? utilisation forward, we believe that it is vital use often require expensive imported to involve all key players at a fundamental solid fuel. By replacing it with our new The objective of this research project is to level. We want to incorporate other low-melting point solid fuel, we will make significantly reduce the cost of solid fuel businesses and organisations so we can all substantial contributions to the spread of rockets, with the final milestone being the benefit from these proprietary technologies related scientific education to the younger practical application of this fuel to a rocket in practical space applications. Katazen generation. l on the same scale as Epsilon. This will is a mid-scale private manufacturer that enable us to increase the frequency of small develops low-melting point resins for

36 www.impact.pub Epsilon rocket ©JAXA

The future of rocket fuel

Researchers at the Japanese Aerospace Exploration Agency (JAXA) are propelling humanity further than ever before by working in partnership with industrial partners to create low-cost, high-grade rocket fuel

Pushing the final frontier is an incredibly Morita’s team has already successfully tested low melting point propellant for real use with expensive endeavour, and as a result, space their innovative low melting point solid rockets. It must have a low melting point, exploration programmes take many years and rocket fuel in model rocket test launches. As preferably being able to melt in hot water huge budgets to complete. Vast resources in a result, they have been working on scaling at around 90 °C and be able to withstand terms of talent, finances and research work are up these developments to produce fuels that the vibrations and shock of a rocket launch. poured into the design of not just the payload can be used in full-scale rockets. They are also ‘The difficulty in the development of a low- that will be taken into space, but also of the exploring cost-saving, innovative technologies melting point solid propellant is the opposing rockets themselves. focusing on the launch itself. requirement for both its thermoplastic and mechanical/physical properties,’ explains The fuel for the rockets represents a With a background in general systems and Morita. ‘We have been working very hard significant investment for space programmes control, specifically related to rocket guidance researching this issue, including the as the energy required to propel the shuttles and spacecraft hardware dynamics, Morita is reformation of the low-melting point resins beyond our gravitational sphere is immense. ideally suited to this work. His specialty is in and oxidiser/resin mixture ratios,’ he adds. Dr Yasuhiro Morita, from the Japanese space launch systems, a niche field that has Aerospace Exploration Agency (JAXA), and seen him successfully building a robust, high- Morita’s ground-breaking solid fuel relies on his team have been developing new, high level control system for the M-5 rocket. ‘As the addition of a thermoplastic resin, and the performance, low-cost solid rocket fuels that the predecessor of the Epsilon launch vehicle, process he has developed can be modified to could revolutionise the industry. ‘Much like the developments on the M-5 saw our group allow smaller scale manufacturing to enable our Epsilon rockets, our country’s solid-fuel as one of the world pioneers in developing a smaller facilities to produce it. ‘With grant- rockets have been taking us to the global practical system utilising the H-infinity control funded research and cooperation from a local forefront of technology and development, theory for satellite launch vehicles,’ comments government, our partners, UE and THINKY, bringing huge contributions to the small- Morita. ‘We also successfully developed an have attempted to build a prototype mixer the scale satellite launch community,’ he autonomous antenna deployment mechanism size of a standard laboratory,’ he outlines. ‘The highlights. ‘We must now work on reducing for the Martian probe Nozomi.’ mixer has a combined rotation and revolution the operational costs involved in these cycle and automatically mixes the low-melting projects, and this means reducing the cost GROUND-BREAKING METHODOLOGY point resin and oxidiser into a solution with of fuel.’ There are many important considerations to heat introduced by friction as it operates.’ take into account when developing an effective He explains that no additional heating is

www.impact.pub 37 required and the hardening process at normal single year, so these large-scale facilities are developing his solid fuel for large scale rockets temperatures can complete in a significantly usually never used for the rest of that time,’ like the Epsilon. By working on the mechanical short period as is not a time consuming he outlines. This inefficiency of large-scale properties of his existing product, as well as chemical reaction. This has resulted in a huge manufacturing with low output frequency and improving refuelling methods on large scales, reduction in production time, and Morita has long production times is one reason why costs he hopes to drive his research forward to been able to finetune the process so that the remain so high for solid-fuel rockets. benefit space research. Morita and his team timeframe from mixing to ignition is just two hours. ‘This marks an incredible improvement Much like our Epsilon rockets, our country’s solid-fuel from a couple of weeks it previously took to produce the fuel and represents what we rockets have been taking us to the global forefront of believe is a historical first in solid-fuel rocket innovation,’ enthuses Morita. technology and development, bringing huge contributions to the small-scale satellite launch community CHALLENGING THE ODDS These innovations are achieved in the face of great challenges as they overturn much of PUSHING THE BOUNDARIES have already made great strides in developing the accepted theories on solid rocket fuels. Solid rocket fuel manufacturing is currently a ground-breaking new solid fuel for evolving ‘All solid fuels in use today have some sort an intensive and inefficient process and a the rocket technology and his contributions of irreversible thermosetting property, and contributing factor to the high cost of space towards youth education will hopefully begin as such require large-scale manufacturing programmes. Where a low-melting point to bear fruit as more institutions are able to equipment,’ Morita states. In addition, the propellant such as that developed by Morita provide young scientists with the opportunities equipment used for this process can only be and his team can be used instead, a huge to use model rockets in their education. l utilised infrequently, whereas Morita’s low efficiency in cost and production times can melting point propellant comprises a reversible be achieved, saving considerable resources. thermoplastic component. ‘Owing to this The impact that this could have on space reverse nature, smaller-scale equipment can be development and utilisation cannot be over- used for continued, uninterrupted production,’ stated and it could prove to be a major leap Project Insights he continues. forward in space research. FUNDING Japan Society for the Promotion of Science, Ahead of the further challenge for a fuel with Although Morita’s solid fuel is currently rated Grants-in-Aid for Scientific Research opposing requirement for thermoplastic and model rocket grade, he is close to creating a (KAKENHI) Scientific Research (A) Grant mechanical properties, the reconstitution of rocket-grade version of the fuel as a practical- 19H00805 the propellant, a basic element of a solid-fuel scale sounding rocket application is planned rocket is probably one of the biggest obstacles next year. Yet even as a model rocket grade COLLABORATORS facing the researchers. ‘Currently, a powder – product, his work can have a big impact. ‘At • Hokkaido Aerospace Science and usually a mixture of ammonium perchlorate as the moment, most model rockets built for Technology Incubation Centre (HASTIC) • IHI AEROSPACE Co., Ltd. (IA) the oxidiser and aluminium as a metallic fuel educational purposes use expensive imported • IHI AEROSPACE ENGINEERING Co., – is combined with a thermosetting resin that solid fuel,’ he explains. ‘The high cost of Ltd. (ISE) makes the hardening process an irreversible acquiring fuel inhibits the use of these rockets • Institute of Space and Astronautical thermosetting procedure,’ observes Morita. for research, and by replacing this with cheaper Science, Japan Aerospace Exploration This manufacturing process requires huge alternatives, we can bring the use of model Agency (ISAS/JAXA) facilities as the entire fuel for each launch needs rockets within the financial reach of more • Institute of Space Utilization Technology to be made in the limited numbers of batches. educational institutions.’ This will stimulate (ISUT) • Katazen Co., Ltd. ‘In the case of JAXA’s large-scale operations, growth in scientific education for young people. • NOF Corporation launches can only be made a few times in a Looking forward, Morita has his sights set on • THINKY CORPORATION • Uematsu Electric Co., Ltd.

CONTACT DETAILS Professor Yasuhiro Morita

T: +81 50 3362 6234 E: morita.yasuhiro@jaxa.jp W: http://global.jaxa.jp/activity/pr/jaxas/ pdf/jaxatoday008.pdf - https://global.jaxa. jp/projects/rockets/epsilon/

BIO Professor Yasuhiro Morita is based at the Department of Space Flight Systems, ISAS/ JAXA. He has made major contributions for more than 35 years to the fields of astrodynamics and space propulsion. Morita has also served as the project manager of the M-V and the Epsilon launch vehicles, Japan’s advanced solid Static firing test of the low-melting point propellant ©Uematsu Electric Co., Ltd. fuel launcher.

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