satellite, hybrid rocket, space medicine, and ... rocket WG will take care of the development of small .... as an abbreviated expression of cascaded multistage.
24th, MIYAZAKI
ISTS 2004-u-8
Hokkaido Aerospace Science and Technology Incubation Center (HASTIC) as a Local Space Farm Harunori Nagata1), Ryojiro Akiba2), Kenichi Ito2) 1) Hokkaido University, Japan 2) Hokkaido Aerospace Science and Technology Incubation Center, Japan
24th International Symposium on Space Technology and Science Miyazaki, Japan May 30-June 6, 2004 24th International Symposium on Space Technology and Science 1-18-2, Shinbashi, Minato-ku, Tokyo 105-0004, Japan Tel : +81-3-3519-4808, Fax : +81-3-3519-9998
ISTS 2004-u-8
Hokkaido Aerospace Science and Technology Incubation Center (HASTIC) as a Local Space Farm Harunori Nagata1, Ryojiro Akiba2, Kenichi Ito2 1
2
Department of Mechanical Science, Hokkaido University Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628, JAPAN (E-mail : nagata@eng.hokudai.ac.jp)
Hokkaido Aerospace Science and Technology Incubation Center (HASTIC) Abstract
HASTIC, the Hokkaido Aerospace Science and Technology Incubation Center, was established June 2002 to create new industries applying space-related technologies and fostering of space technical experts and researchers. HASTIC is not a research and development institute but an information center among scattered space-related facilities and university laboratories in Hokkaido. Another function of HASTIC is a local key player of space development, contributing to the progress of national space development activities. HASTIC believes that various space development activities performed at “local space farms” distributing all over the country is indispensable to expand the base of space-related human resources and drive national space exploration and development. HASTIC aims to be the center of space-related activities in Hokkaido and the flagship of local space farms in Japan. Four working groups are active in HASTIC presently. These are micro satellite, hybrid rocket, space medicine, and microgravity utilization working groups. Based on these four working groups, HASTIC takes cooperation closely with local industries and space-related organizations in the country to realize our ultimate goal, to create space industries in Hokkaido.
1. Introduction HASTIC, the Hokkaido Aerospace Science and Technology Incubation Center, was established in June 2002, and it obtained a legal certification as an incorporated nonprofit organization in Jan. 2003. Main purposes of HASTIC are to create new industries Copyright© 2004 by the Japan Society for Aeronautical and Space Sciences and ISTS. All rights reserved.
applying space-related technologies and fostering of space technical experts and researchers. HASTIC is not a research and development institute but an information center among scattered space-related facilities and university laboratories in Hokkaido. Another function of HASTIC is a local key player of space development, contributing to the progress of national space development activities. We believe that various space development activities performed at “local space farms” distributing all over the country is indispensable to expand the base of space-related human resources and drive national activities of space utilization, exploration, and development. HASTIC aims to be the center of space-related activities in Hokkaido and the flagship of local space farms in Japan. Current activities of HASTIC are (1) management of research and development working groups, (2) holding of seminars regarding space-related technologies, (3) publication of a mail magazine, (4) holding of community seminars to introduce the latest space-related technologies to general public, and (5) holding scientific meetings regarding space-related research field including space environment utilization. Four working groups are active in HASTIC presently. These are micro satellite, hybrid rocket, space medicine, and microgravity utilization working groups. This paper describes the outline of the organization and some ongoing projects, and corroboration relationships among the working groups.
2. Outline of the organization and projects Space environment utilization has a history of about 30 years, extending back to the project Skylab. However, the initial expectations such as dreamlike new materials or new medicines developments have
mutation and medical experiments with mice and rats not been achieved yet. The reason of the present in orbit [1]. The space experiments will be conducted disappointing achievements is that the platforms of by a small recoverable biosatellite. The detail of the space experiments are very limited and the researchers small recoverable satellite will be hereinafter described. cannot accumulate data promptly. A factor that has The micro satellite WG will contribute to the caused the limitation of the platform is that the development of the small biosatellite. The hybrid researchers and engineers of the space utilization field rocket WG will take care of the development of small have been supplied mainly large-scale and intensive deorbit thrusters. To develop experimental apparatus experimental platforms. Large-scale and intensive for the user module of the biosatellite, operation tests experimental platforms are inappropriate for the space utilization because the space environment users are extremely varied. They cannot share a multipurpose HASTIC Organization Chart apparatus. The experimental durations are extremely varied also. The conventional approach supplying General meeting NPO member expensive multipurpose equipment and selecting the Supporting member research themes that can use the equipment can nip excellent space utilization ideas in the bud. Because the experimental durations are extremely varied, the Board meeting Management planning committee space environment users are forced to conduct many adjustment works among the users sharing single HASTIC office platform. To solve this problem and enhance the space utilization activities, the platform of the space Four research working groups utilization should make the shift from the conventional Micro satellite WG large-scale and intensive system to the small-scale and Hybrid rocket WG distributed one. Microgravity utilization WG HASTIC, the Hokkaido Aerospace Science and Space medicine WG Technology Incubation Center, links the space Two business working groups environment users and the space engineers together to develop space utilization technologies precisely Education and human resource development responding to the demand. Figure 1 shows the Public information WG organization chart of HASTIC. Four research working groups, i.e., micro satellite, hybrid rocket, Fig. 1. Organization chart of HASTIC. microgravity utilization, and space medicine, are underway now. Hybrid rocket and HASTIC project outline micro satellite working groups consist of members with space engineering backgrounds. The space medicine Hybrid rocket WG: Microgravity utilization WG: WG is a group of space environment ・ CAMUI hybrid rocket ・ Microgravity combustion research ・ Staged combustion hybrid rocket ・ Development of new microgravity tools users in the medical field. The microgravity utilization WG consists of both users and engineers of Three minutes microgravity, especially on the second Operation test of the test microgravity experiment module under microgravity by CAMUI rocket time scale. These groups are Development of by CAMUI rocket recoverable satellite working on several projects together with strong partnerships. Figure 2 shows some ongoing projects and Space medicine WG: Micro satellite WG: contributions of working groups to ・ Recoverable bio-satellite in orbit ・ Development of micro satellite each project. The space medicine ・ Field medicine WG is planning experiments of breed Fig. 2. Project outline ongoing in HASTIC. improvements of edible plants by 1
by exchanging energy between potential and rotational energy of the flywheel. Because a part of potential energy is transformed into rotational energy, the drop phase of yo-yo cannot produce microgravity condition if no modification is made. Figure 4 shows the basic idea of the yo-yo type microgravity system. The dynamic equation of the drop capsule and the flywheel is
under microgravity are necessary. Small reusable sounding rockets, the CAMUI hybrid rocket being developed by the hybrid rocket WG, will afford three minutes microgravity condition by a ballistic flight for this purpose. Some members of the microgravity WG will be the users of the microgravity condition produced by CAMUI hybrid rocket also.
dv 1 = g, K = dt 1 + K 2 / r02
3. Microgravity utilization
I M
where v, t, r0, g, and M are the velocity of the drop capsule, time, the diameter of the shaft entwined by the thread, acceleration of gravity, and the mass of the drop capsule, respectively. Equation 1 shows that the apparatus can produce any low-gravity environment by adjusting K/r0, and the acceleration approaches g, i.e., the free fall, as r0 increases. However, the large r0 causes high impact when the capsule turns upward, giving away the advantage of the yo-yo system. One solution to avoid this problem is employing small K/r0 at drop and ascent phases and large K/r0 at the turnaround phase. The yo-yo type microgravity system uses a spiral pulley Fig. 5 shows during the braking and launching zone to realize this solution. The spiral is logarithmic, being represented as r = r0 exp(− cθ ) . (2)
Microgravity utilization WG mainly uses short period microgravity condition produced by a drop tower. Figure 3 shows an example of how the short period microgravity condition is used [2]. The photomicrograph shows carbon nanotubes in soot of a diffusion flame obtained under microgravity. Because the distributions of velocity, temperature, and density in the gas phase are easy to control due to the lack of convection under microgravity, microgravity condition is suitable to the mass production and the clarification of the production mechanism of carbon nanotubes. Drop tower most commonly provides short period microgravity. The microgravity utilization WG is developing a 45 m drop tower providing three seconds microgravity, which will come into service by the next October. While drop tower produces microgravity by only the drop phase, a quarter height tower can produce microgravity of the same duration if both ascent and drop phases are available. However, they have thought that this idea is not realistic because a launch mechanism is necessary to use the ascent phase, requiring huge facilities and heavy cost. The microgravity utilization WG has proposed yo-yo type microgravity system to use both ascent and drop phases by a simple and inexpensive mechanism. Yo-yo consists of a flywheel and a piece of string, and makes rise and fall
The dynamic equations of the drop capsule and the
Drop capsule Mass: M
Flywheel Moment of inertia: I
Braking and launching zone
Fig. 3.
(1)
CNTs produced under microgravity.
Fig. 4. 2
Yo-yo type microgravity system.
flywheel are
M
dv = Mg − T dt
(3)
dω = Tr dt
(4)
I
rocket has a potential to reduce the launch cost because the propellant is very cheap and it does not use any explosive and liquid fuel, resulting in low management cost. However, the drawback of hybrid rocket, i.e., poor thrust comparing with solid rocket, has hampered the practical application for small sounding rockets. To solve this problem, the hybrid rocket WG has proposed a new fuel configuration designated CAMUI as an abbreviated expression of cascaded multistage impinging-jet [3]. Figure 8 shows the schematic view of the fuel grain. Several cylindrical fuel blocks with two ports line up behind each other with small gap spaces in the combustion chamber. A key feature of this design is that the oxidizing gas collides with the forward end surfaces of fuel blocks, enhancing the heat
where ω and T are the angular velocity of the flywheel and the tension of the string, respectively. Rearranging equations 3 and 4, keeping in mind that v = rω 1 + c 2 , gives the following relation.
dv = dt
c Mg − Iω2 r I M+ r 2 1 + c2
(5)
Note that Eq. 5 coincides with Eq. 1 when c equals zero. As Eq. 5 shows, the length of the braking and launching zone and the deceleration of the drop capsule during the braking can be controlled by changing the value of c. The yo-yo type microgravity system has already been at the stage of commercialization. Figure 6 shows a production version for educational purposes, providing one-second microgravity in room. This microgravity duration is equal to that of a 5 m drop tower. Although the level of microgravity yo-yo method can provide is not better than 10-2 g, better quality of microgravity is available by employing an inner capsule falling freely in the drop capsule.
θ
r0
r
Fig. 5.
Spiral pulley.
4. Development of reusable sounding rocket There is a great demand for microgravity on the minute time scale by a sounding rocket from researchers mainly in material and medical fields. However, the microgravity of this time scale is hardly used, especially in Japan, because of the extremely high launch cost of sounding rocket. The hybrid rocket WG is developing a fully reusable small-scale hybrid rocket, which uses plastic as fuel and liquid oxygen as oxidizer, to achieve a serious cost reduction. Figure 7 shows the outline of the ballistic flight experiment. The vehicle produces microgravity of about three minutes by a ballistic flight to 110 km high. After the experiment, the vehicle descends by a rotating glide around a target. The vehicle carrying a user module is recovered by a splashdown on a lake and the vehicle is reused to the next flight. Hybrid
Fig. 6. 3
A production version of the Yo-yo type i it t
required to be inexpensive, simple, and convenient. Key technologies to fill these demands are space flight with GPS navigation system, development of service satellites to provide electric power and communication with ground stations, unmanned operation using robot technology, automatic rendezvous and docking technology, and automatic recovery system. Japan has developed all these technologies already and the small recovery satellite system is feasible without any doubt. Figure 10 shows a schematic view of the recoverable satellite. The satellite consists of a standardized module for rendezvous and docking and a user module for space experiment. To provide electric power and communication service with ground stations to the recoverable satellite, service satellites are prepared in orbit. The recoverable satellite docks to a service satellite according to need. After the end of the mission, the onboard rocket engines decelerate the satellite to make an entry into the atmosphere. Figure 11 shows the structural plan of the recoverable satellite system. Because the application of the infrastructures on the ground (ground stations and recovery systems) and in orbit (service satellites) is not limited for the recoverable satellites, government
transfer from the diffusion flame to the solid fuel and the mixing of oxidizer and gasified fuel. Because of the high regression rate and the simultaneous burning of all fuel blocks, the CAMUI hybrid rocket matches the thrust of conventional solid rockets. Recently, the authors have succeeded to launch 50 kgf thrust class flight models of CAMUI hybrid rocket and proved the reliable performance of the motor in the flight condition [4]. A winged launch, gliding, and landing test followed these accomplishments this year [5]. Figure 9 shows a schematic view of the winged test vehicle. The length and span of the delta wing are 1280 mm and 1000 mm, respectively, and the weight of the vehicle is 16.5 kg including 1.2 kg propellants. The vehicle glided with the terminal velocity of about 40 m/s was successfully recovered on a snowfield without injury. The hybrid rocket WG is planning to provide three minutes microgravity to 20 kg payload with the price of $50,000 per flight, and the researchers in the space medicine WG will be the first users.
5. Small recoverable satellite system HASTIC has proposed small recoverable satellite system to realize small-scale and distributed space platforms. This system is
Copper pipe Fuel block Injector
Fuel spacer
Ablator
Graphite nozzle
Fig. 8. Grain of the cascaded multistage impinging-jet (CAMUI) hybrid rocket.
Fig. 7. Ballistic flight experiment by a winged hybrid rocket system.
Fig. 9. 4
Schematic view of the winged test vehicle.
Thrusters for should establish the infrastructures. attitude control Hybrid rocket The rendezvous and docking module User module has a potential to be a business and space-related companies are likely to Devices for develop the module. The user recovery module deals with the varied demands of the users in the space utilization field. Assuming that the satellite is 500 kg in weight and the Oxidizer tank launch cost is $10,000 per kilogram, BUS module Docking port the launch cost is about $5 million. The total cost including the operation Fig. 10. Schematic view of the recoverable satellite. and recovery will run out at $10 million. Although this price and the flexibility of the Service satellite in orbit system are attractive comparing with the conventional Government space experiments in ISS or space shuttle, the price is still out of the price range for general space users. Rendezvous Reduction of the launch cost is indispensable to docking User module module expand the space utilization field.
Ground infrastructure
6. Conclusion
Users
Space-related companies
A key function of HASTIC is to link the space environment users and the space engineers together to develop space utilization technologies precisely responding to the demand. The space environment users are extremely varied. The durations of their space experiments are extremely varied also. HASTIC believes that the platform of the space utilization should make the shift from the conventional large-scale and intensive system to the small-scale and distributed one to enhance the space utilization activities. Solutions HASTIC is proposing are the short period microgravity by the yo-yo system, microgravity on the minute time scale by the fully reusable CAMUI hybrid rocket, and the platforms in orbit by the recoverable small satellite system.
Fig. 11. Structural plan of the recoverable satellite system.
Microgravity Experiments Opportunity and Diffusion Flame Synthesis of Carbon Nanotubes under Microgravity,” Proceedings of the 41st Combustion Symposium, pp. 200-202, 2004 (in Japanese). [3] Nagata H., Watanabe, M., Sanda, T., Satori, S., Aoki, Y., Kudo, I., Akiba, R., Kubota, I., “Improvement of Fuel Regression Rate by Impinging Jet for High Thrust Hybrid Rocket Motors,” Proceedings of the 22nd International Symposium on Space Technology and Science, Vol.1, pp.121-126, 2000. [4] Nagata, H., Watanabe, M., Nakayama, H., Satori, S., Takada, T., Shiba, K., Toyoda, K., Kudo, I., Ito, K., Akiba, R., Kubota, I., “Development Study at University Laboratories on Small Scale Reusable Launch Systems Part 1: Project Outline and Development of a Jet Impinging Type Hybrid Rocket Engine,” 22nd International Symposium on Space Technology and Science, ISTS-2002-g-19, 2002.
References
[1] Yano, S., Yoshioka, M., Torigoe, T., Kaba, H., Uyeda, I., Otsuka, K., Matsubayashi, K., “The Use of mice/rats for space-medicine and production of fertile food seeds under microgravity and cosmic rays,” Proceedings of the Twentieth Space Utilization Symposium, pp.144-147, 2004 (in Japanese). [2] Ito, H., Fujita, O., Ito, K., “Creation of 5
