Microsatellites As Research Tools, Proceedings of Cospar Colloquium on Microsatellites as Research Tools

389 Pages·1999·27.89 MB·1-389\389

by  Fei-Bin Hsiao (Eds.)

PREFACE
The COSPAR Colloquium on Scientific Microsatellites was held between December 14-17 1997 in the
Institute of Aeronautics and Astronautics (lAA), National Cheng Kung University (NCKU), Tainan,
Taiwan, gathering about 150 participants from 18 countries in 5 continents. In order to reflect the
increasing importance and interest of the microsatellites in high technology and scientific applications in
space, the Colloquium on Microsatellites as Research Tools was organized to promote its usage and
technology development and to foster the intemational cooperation, especially in the area of Asia pacific
region. The Colloquium started in the first day's morning with the Welcome Address provided by
Professor Gerhard Haerendel, President of COSPAR, but unexpectedly read by Dr. Wing H. Ip to express
his wishes and regards to the success of this Colloquium. The Opening Session was then followed by
three distinguished guesses speaking. It was truly honored to have the participation of Dr. Jin Wu,
Minister of Education and former President of NCKU who clearly addressed the current and prospective
of space education and research activities in Taiwan. Prof Chao-Han Liu, President of National Central
University and also the space mentor and navigator of space research in Taiwan, then gave a very up-to-
dated presentation about the space development in Taiwan. The final Opening Session was concluded by
Professor Cheng-I Weng, President of NCKU and host of the Colloquium, showing his ambitious
willingness of leadership in space research in NCKU in addition to his warm welcome to all honored
guests and participants from abroad and domestic. The Keynote Presentation was given by the honorable
guest Dr. Jin-Fu Chang, Vice Chairman of National Science Council, to speak on "Striving toward a
technologically-advanced nation - vision for the 21st Century's science and technology."
Both oral and poster presentations of the contributed papers were organized in the colloquium in two days.
Five major themes arranged in serial were addressed: regional development, lessons learned, innovations,
scientific applications, and education. A special session was organized as well by the Organizing
Committee and supported by the National Space Program Office to present its development of the
Taiwan's satellite program and the current status of ROCS AT-1, which is scheduled to be launched at the
end of 1998 or beginning of 1999. Dr. David F.H. Chu, the Principal Investigator of ROCS AT-1, gave the
speech and answered all questions as related to this satellite. The Round Table Discussion Session was
arranged by Dr. Rickard Lundin and Dr. Wing Ip at the second day's afternoon to wrap up all conmients
and ideas in response to the paper and poster presentations. At least two conclusions were remarked:
Microsatellite in general is a very good means for doing space research and technology development and
a suitable vehicle to promote intemational collaborations. In addition, COSPAR Headquarters should
consider in the near future to host the second microsatellite colloquium such as the current one in
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realizing and enhancing the microsatelHte and related activities especially for the developing countries in
the Asia-pacific region.
Apart from the indoor paper presentations, two technical field trips outdoors were arranged after all paper
sessions, which included the visits to the Aerospace Science and Technology Research Center of NCKU
in Tainan County and the Hsinchu Science-based Park in Hsinchu City. The Hsinchu's trip by luxurious
bus contained the visits to Science Park Administration, National Radiation Synchrotron Laboratory,
Microelectronic Technology, Inc., and National Space Program Office, where to witness the real hardware
oftheROCSAT-1.
It should be grateful for the technical support by Dr. R. Lundin and Dr. Wing Ip who chaired the
Scientific Organizing Committee, and the local support by Prof Fei-Bin Hsiao and Lou C. Lee who
chaired the Local Organizing Committee. The excellent logistic support by the staff's and students in the
Institute of Aeronautics and Astronautics of NCKU were highly acknowledged. Special thanks extend to
such agencies who provided the financial supports as COSPAR, Academia Sinica, Ministry of Education,
National Science Council, Aeronautical and Astronautical Society (Taiwan), Center for Aerospace
Science and Technology, Tainan Hydraulics Laboratory. National Cheng Kung University serving as the
main sponsor university sincerely thanks to the COSPAR Headquarters for providing the opportunity with
honor to host this international event.
Finally, I would like to express my sincere thanks to Miss Linda Lin, who help type and edit all submitted
manuscripts, for her excellent performance and extreme patience, and to Elsevier Science Co. for
publishing this volume as the COSPAR Colloquia Series.
Fei-Bin Hsiao, Ph. D.
Editor
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KEYNOTE ADDRESS
Gerhard Haerendel, COSPAR President
Dear Distinguished Delegates, Ladies and Gentlemen,
I against my original intention I had to cancel my participation in this symposium on short notice, because
my presence was urgently required in Germany, in order to be present during a critical phase of
operations of our EQUATOR-S satellite, which was launched on December 2. Therefore, this message
has to be read to you, I apologize and hope for your understanding. The topic of this Colloquium,
Microsatellites as Research Tools, is particularly close to my heart since I started promoting research
using small satellites about a decade ago. I am very pleased to see that the concept is becoming accepted
in the scientific community, that many meetings now address the topic from one angle to another, and
that results are being obtained from research out with such tools.
However, let me also express a warning that we not be carried away by the enthusiasm arising from
opportunities created by small and mini-satellites. In my mind these tools have a role complementary to
that of big observatories and space probes, adding flexibility, short lead-times, and alternate means of
procurement and of sharing responsibility. For many tasks in astronomy, solar system research, and Earth
observations big missions will be indispensable and, after careful analysis, may prove to be more cost
effective than a number of small missions accomplishing the same work.
As we approach the end of the year, it seems fitting to take a moment to acknowledge certain recent
successes that will certainly have to a greater or lesser degree an impact on our work and in some cases
perhaps even on your discussions this week. I cannot but admire the elegance and technical prowess of
the Pathfinder mission to Mars, the success of which this past summer so justifiably enthralled tens or
perhaps even himdreds the potential of robotic exploration in space, especially encouraging in this era of
limited fimds.
In the past year we also witnessed successful launches of important space projects like the NASA/ESA
Cassini/Huygens mission to Saturn and its satellite Titan and the deployment by ISAS of the Haruka
space radio-telescope, the space segment of the MLBI Observatory. Let me also mention the spectacular
success of the Italian-Dutch Beppo-SAX satellite for X-ray astronomy. Its detection of the X-ray
afterglow of gamma-ray bursts, combined with optical and radio data, seems to have positively proved,
after three decades of debate, that these enigmatic bursts originate at cosmological distances.
I should like also to warmly salute the obvious scientific and technological maturity of our Spanish
colleagues who successfully launches their first satellite (Minisat-01) and express my satisfaction with the
positive decision by ESA to rebuU the Cluster mission.
To return to matters of more immediate concern, I have no doubt that this Colloquium will be very
fruitful given the dynamism that currently characterizes the Taiwanese space community. We have all
been impressed by the great strides made in recent years by our colleagues here. More generally,
COSPAR looks with great expectation and hope to the invigorating drive of many of the scientists whose
countries are represented at this meeting to master the techniques and technologies enabling man to
exploit successfully the potential of mini and microsatellites.
I would be most happy if your discussions these next few days also resulted in reinforced international
cooperative efforts, for I am convinced that it is only through greater cooperation among space
researchers on a wide scale that we can overcome limitations imposed by ever tighter budgets. COSPAR
shall, of course, continue its efforts to promote international collaboration, and as the President of the
premier organization working to this end specifically on behalf of space researchers, I am pleased to
inform you that as a participant in this meeting you will be conferred the status of Associate in our
committee.
As you may know, COSPAR's next big event after this Colloquium will be its 32"** Scientific Assembly
which will be held in July 1998 in Nagoya. Those of you who have seen the Call for Papers know that
this Assembly will be a memorable event because of the strength of the science that shall be presented.
The Nagoya Assembly will also be a special event because it marks the 40*** anniversary of our
committee's service to the international space research community. I hope many of you will attend the
Assembly next summer in order to help us celebrate this important anniversary and because I am sure that
you will all find in the program scientific events that suit your individual interests.
I would particularly like to draw your attention to the fact that COSTAR'98 will provide an opportunity
to increase interaction between the scientific and engineering communities through a joint event
organized with the International Astronautical Federation (lAF) entitled "Science and Engineering
Aspects of Solar System Exploration". As mutual understanding and smooth cooperation between the two
communities is a springboard for success in all our fields. I that exploration and utilization of space is
dependent on collaboration between researchers and engineers and on the close coordination of their
efforts. Even the greatest degree of interaction between the research and engineering communities cannot
be deemed excessive. Fortunately, this situation is well-understood and appreciated by the majority of
those concerned which includes many of us here today.
On this note, distinguished delegates, ladies and gentlemen, I would like to wish you all a most agreeable
and worthwhile Colloquium.
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ROCSAT PROGRAM AND SOME RELATED RESEARCH TOPICS
Jia-Ming Shyu
Director, National Space Program Office, 8th Floor, No. 9 Prosperity First Road, Hsin-Chu Science-
Based Industrial Park, Hsin-Chu, Taiwan 30077, ROC
ABSTRACT
While the ROCSAT-1 project proceeds to the integration and test stage, we expect to launch the first
satellite of the Republic of China with three pay load instruments on board in December 1998. The
following ROCSAT series are now in planning. Among them a supporting program for "microsatellite as
research tool" with international cooperation is also under consideration. Besides introducing ROCSAT-
I's recent development, this presentation will suggest some areas of interest for further discussion. The
results of the discussion may be included into the future NSPO's mission oriented research topics of the
following ROCSAT projects.
PREFACE
The ROCSAT program started from October 1990. The first runner of this program, the ROCSAT-1
project, granted it's spacecraft contract on June 1994. Subsequently, the ROCSAT Ground Segment
(RGS), the Ocean Color Imager (OCI) payload, the Ionosphere Plasma and Electrodynamic Instrument
(IPEI) payload, the Experimental Communication Payload (ECP) and the integration and test facilities
were contracted to foreign and domestic companies. Under the close cooperation between NSPO and
contractors, this project is going on smoothly and has finished integration of spacecraft and payloads.
Now the satellite is under testing. We expect to launch ROCSAT-1 some time between December 1998
and March 1999 with the launch vehicle LMLV-1 from Cape Canaveral, Florida, USA.
Since all three payloads of the ROCSAT-1 have been delivered and integrated to satellite, and science
teams of OCI, IPEI and ECP have been established and are preparing for the experiments quite a few time,
it is now impossible to add on any extra payload to the satellite. Any researcher, who has interests about
the experiment using these payloads, may contact directly with following primary investigators (PI) of the
science teams:
OCI — Prof Sien-Wen Li, National Taiwan Ocean University (NTOU)
e-mail: [email protected]
IPEI — Prof Shin-Yi Su, National Central University (NCU)
e-mail: 2700146@ncu865 .ncu.edu.tw
ECP — Prof Yen-Hsyang Chu, National Central University (NCU)
e-mail: [email protected]
Prof Szu-Lin Su, National Cheng Kung University (NCKU)
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e-mail: [email protected]
Prof. Yun-Chang Chen, National Tsing Hua University (NTHU)
e-mail: [email protected]
After the launch of ROCS AT-1, the downlinked data of ROCS AT-1 will be open to science community
worldwide through Science Data Distribution Centers (SDDC) located in NTOU (for OCI), NCU (for
IPEI) and NSPO (for ECP).
The mission life of ROCS AT-1 is two years and design life is four years. The extended mission in the
third and fourth years after launch has not been decided yet. We will consider any meaningftil suggestions
when the time is near.
THE TREND OF SMALL/MICRO SATELLITE AND CONSTELLATION
As we all well know, the recent satellite development trend is "smaller, faster and cheaper" as advocated
by NASA. Besides, we can add "constellation" as one of the new trends. Smaller is possible through
fimctional simplification, faster is conceivable through reduction of documents and tests, and cheaper can
be achieved through deduction of documents and tests, and cheaper can be achieved through deduction of
redundant parts and modulation. Constellations to upgrade the ftmction from static to dynamic or from
non-real-time to real-time through mission repeat and it will bring far more benefits than of a single
satellite.
Tlie selection of subsequent ROCSAT missions is concentrated on small satellites and based on the
requirements survey, supply sources investigation, and the trends of space technology development. It
shows that small satellites and microsatellite constellation are suitable for domestic demand on remote
sensing, meteorology, and science research.
RESEARCH TOPICAS OF FOLLOWING ROCSAT SERIES
While ROCSAT-2 is defined as a remote sensing satellite and ROCSAT-3 is planning as a microsatellite
constellation for meteorology, some traditional major research topics for the main missions are under
planning. Besides, there are some research topics needed to discuss.
Detection of Groundwater OverJJtilizaj[qn
The southwest coast of Taiwan has suffered from flood in recent years. The flood was induced fi-om
landsinking, which according to the report [1], cost us in average 11 Billion NT dollars every year. The
over suction of groundwater by aquaculture farmer is the major cause of landsinking. The Environment
Protection Bureau warned this situation, but was not capable to identified anyone who excessively
pumped the groundwater out to feed his fish pond.
If we can use suitable instrument, such as inft-ared sensor from LEO satellite to get the water temperature
distribution map with isothermal line, then we can see the cold/warm water sources. These cold/warm
water sources are identical to the place where the groundwater, with different temperature as nearby areas,
pours in. In addition, the density of isothermal lines will show the volumetric flow of the groundwater. It
is therefore possible to identify the offender of the environment protection.
Rain may disturb the water temperature distribution. However, on raining days the fishfarmer will not use
groundwater to dilute their fish pond. So, there is no need to remote sense water temperature in raining
days.
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Microclimate
The resolution of the cloud maps provided by the GEO meteorological satellite is about 3 km nowadays.
This resolution is obviously too rough for small, mountainous and densely populated area like Taiwan.
We need more accurate microclimate information such as cloud maps with resolution about 200 m and
delivered every hour. Through integration of GEO cloud maps with lower resolutions and LEO cloud
maps with higher resolution we expect to have near continuos pictures of cloud motions. From these
pictures and other weather informations we may differentiate and derive local wind speed, vapor, air
pressure, air temperature, etc. more precisely.
Qualifying of Space Use Components
To secure the reliability of the satellite, it is important to test the components of the spacecraft as well as
payload instruments before launch. We use ground test facilities to simulate space environment for
verifying the survivability of the satellite. Nevertheless, it is still needed to prove its reliability in the real
space environment.
Since constellation has many small satellite with the same conditions, we have more test opportunities to
test components or instruments. The construction and circuitry of small satellite is mostly rather simple,
and the down data of the satellite is far less than the big satellite. Therefore, it is easier to add on some
ground-qualified components or instruments for space proving.
Space Gravity Field of Earth
The gravity of the earth is not homogeneous around the earth at the same altitude. And the changes of the
gravity at the same moment in different places are not thoughtfully investigated so far. To better
understand our planet earth it is desirable to measure the gravity of the earth using constellations of
equally distributed satellites. The high accurate position determination with the GPS receiver on board of
the micro-satellite constellation may precisely determine the gravity field.
Sprites
On the terrestrial upper atmosphere there are many newly discovered phenomena associated with
thunderstorms, such as red sprites, blue jets, elves, lightening-induced electron precipitation, pairs of VLF
pulses and gamma-ray flashes of atmospheric origin. Observations and theories of these lightning
associated physics have been the subject of special topics sessions on several international scientific
conferences. Direct observations of sprites to date, mainly from ground and airborne, have been limited to
their visible or near-infrared (400-900 nm) emissions. However, numerous micro-physical processes
deriving from these phenomena are expected on general theoretical grounds to released energy over a
broad band of wavelengths extending fi-om the ultraviolet into the infrared. It is difficult to observe the
ultraviolet emission from ground and a systematic observation from satellite becomes important. Use of
the sprites imaging science payload on the ROCSAT-2 program will provide a first hand systematic
global coverage observation data of these upper atmospheric lighting related phenomena and will have
certain impacts and contributions to the international science community.
CONCLUSION
Although the small and microsatellite as space research tool is well known since the beginning of the
space age in 1950s, its application is limited to amateur area since then. The function and performance of
microsatellite improved quite a lot in recent years in conjunction with the development of ASIC, VLSI
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based microprocessor, lightweight antenna, lightweight spacecraft structure, and MMIC, etc. The
miniaturization of satellite and payload instrument enables microsatellite get breakthrough in many
science and practical application fields.
The lower cost of microsatellite allows more satellites to perform designated missions. The smaller size
and lighter weight of microsatellite makes the launch of microsatellite/constellation either dedicate or
piggyback possible. Moreover, since the concept of backup and reliability of microsatellite is different
from big satellite's, cost reduction from elimination of redundant components and direct utilization of
conmiercial/military components make the micro-satellite more competitive. The future of microsatellite
as research tools is therefore bright. The usage of microsatellite constellation in ROCSAT-3 is hence
feasible.
— 8
AN INTRODUCTION TO THE KITSAT PROGRAM AND THE
ACTIVITIES AT THE SATREC IN KOREA
Soon-Dal Choi, Byung Jin Kim, and Ee-Eul Kim
SaTReQ KAIST, 373-1 Kusung-Dong, Yusung-Gu, Taejon 305-701, Korea
ABSTRACT
The Satellite Technology Research Center (SaTReC) in the Korea Advanced Institute of Science and
Technology (KAIST) is an institute for education and research in the field of satellite engineering, space
science, and remote sensing. SaTReC was selected in 1990 as an Engineering Research Center' (ERC) by
the Korea Science and Engineering Foundation in order to make it the center of excellence in satellite
engineering. It has successfully produced and operated the first and second Korean microsatellites,
KITSAT-1 and 2. A brief description of the history of SaTReC is presented. KITSAT-1 and 2 that
produced some valuable scientific and satellite engineering results are described. The current mission in
the KITSAT series, KITSAT-3 which is an engineering test satellite, is introduced. The activities of the
SaTReC in remote sensing and its participation in international collaboration are also summarized. The
future plan of the development of the new generation satellite, KITSAT-4, is finally envisioned.
INTRODUCTION
The Satellite Technology Research Center (SaTReC) in the Korea Advanced Institute of Science and
Technology (KAIST) is an institute dedicated to the education and research in satellite engineering, space
science, and remote sensing. In 1990, the SaTReC was selected as an Engineering Research Center (ERC)
by the Korea Science and Engineering Foundation (KOSEF), which marked the beginning of the space
activities in Korea. Since then, the SaTReC has acquired the capability to manufacture micro and small
satellites through the international cooperation and the interdisciplinary collaboration in the KAIST. By
sending a number of KAIST graduates abroad since 1989, the SaTReC has obtained the trained personnel
in various fields related to the space.
The SaTReC has successfully developed and operated two micro satellites, KITSAT-1 and 2, the first two
satellites of Korea. Both of them are equipped with several payloads to perform experiments in satellite
engineering, space science, and earth observation. In addition to the scientific results, they produced the
valuable information on the satellite engineering and gave the indispensable experience to engineers.
The SaTReC is presently developing KITSAT-3, a small engineering test satellite, based upon the
experience and knowledge acquired from the two previous missions. It has several improved payloads
such as the Space Environment Scientific Experiment (SENSE) and the multi-spectral optical camera.
The SaTReC has also established the KAIST Remote Sensing Center (KRSC) in 1995 to perform the
research in remote sensing and to support the acquisition, preprocessing,, and distribution of the remote
sensing data in Korea.
9 —
The SaTReC has actively participated in various international activities and is looking forward to the
international cooperation in its future missions. The SaTReC will play a key role in promoting Korea as
one of active countries in space science, satellite engineering, and remote sensing.
OVERVIEW OF KITSAT-1 & 2 MISSIONS
The KITSAT-1 was developed through the international collaboration with the University of Surrey in the
UK. Ten KAIST graduates from the SaTReC were sent to the University of Surrey as postgraduate
students and were deeply involved in the development of the UOSAT-F. With the invaluable experience
they gained from this program, they played key roles in the development of KITSAT-1. Returning back to
Korea, they independently developed the next micro-satellite, KITSAT-2. Figure 1 shows the
configuration of KITSAT-2.
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ASS
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Solar Panel
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DSPE / LEED IIREX
NAV. MAG OCEeICS lMTR ARNASMPOUtTSEKR / OSFCE
EXPANSION / OeC BO
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Antenna-
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System
Figure 1. Configuration of KITSAT-2.
These two satellites, which are very similar in structure but different in their orbits, provide a unique
opportunity to study the effects of the radiation environment characterized by their orbits. Both KITSAT-
1 and 2 carry simple space science experimental modules to measure the radiation particles. Each of them
also has two Earth observation CCD cameras, one for wide angle and the other for narrow angle
observations. In cooperation with a Korean industry, the Samsung Electronics, a color CCD camera was
developed and used as the wide angle camera sensor in KITSAT-2. The general features of two satellites
are shown in Table 1.
Table 1. General features of KITSAT-1 and 2.
KITSAT-l KITSAT-2
Ahitude 1330 Km 800 Km
Inclination 660 98.7 0
Size(mm) 352 X 356 X 670 352 X 356 X 670
Weight 48.6 Kg 47.5 Kg
Power 30W max 30Wmax
Attitude Gravity Gradient Boom Gravity Gradient Boom
Control Magnetorquer: Pointing 5° Magnetorquer: Pointing 5
10