Browsing by Author "Kuo, Ying-Hwa"

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Constellation Deployment for the FORMOSAT-3/COSMIC Mission
(2008-11-01)
Fong, Chen-Joe
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Shiau, Wen-Tzong
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Lin, Chen-Tsung
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Kuo, Tien-Chuan
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Chu, Chung-Huei
The FORMOSA Satellite Series No. 3/Constellation Observing System for Meteorology, Ionosphere and Climate (FORMOSAT-3/COSMIC) spacecraft constellation consisting of six low-earth-orbiting satellites is the world's first operational Global Positioning System (GPS) radio occultation mission. The mission has been jointly developed by the National Space Organization of Taiwan and the University Corporation for Atmospheric Research of the U.S. in collaboration with the Jet Propulsion Laboratory, NASA, and the Naval Research Laboratory for three onboard payloads, including a GPS Occultation Receiver, a triband beacon, and a tiny ionospheric photometer. The FORMOSAT-3/COSMIC mission was successfully launched from Vandenberg into the same orbit plane of the designated 516-km circular parking orbit altitude on April 15, 2006. After the six satellites completed the in-orbit checkout activities, the mission was started immediately at the parking orbit for in-orbit checkout, calibration, and experiment of three onboard payloads. Individual spacecraft thrust burns for orbit raising were performed to begin the constellation deployment of the satellites into six separate orbit planes. All six FORMOSA717-3/COSMIC satellites are maintained in a good state of health except spacecraft flight model no. 2, which has had power shortages. Five out of the six satellites had reached their final mission orbits of 800 km as of November 2007. This paper provides an overview of the constellation spacecraft design, constellation mission operations, constellation deployment timeline evolution, associated spacecraft mass property and moment of inertia results, orbit-raising challenges, and lessons learned during the orbit-raising operations.
FORMOSAT-3/COSMIC Constellation Spacecraft System Performance: After One Year in Orbit
(2008-11-01)
Fong, Chen-Joe
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Yang, Shan-Kuo
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Chu, Chung-Huei
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Huang, Cheng-Yung
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Yeh, Jia-Jing
The FORMOSAT-3 mission, also known as Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), is the third major project of the Formosa Satellite (FORMOSAT) series implemented by the National Space Organization of Taiwan. FORMOSAT-3/COSMIC is a joint Taiwan/U.S. mission consisting of six identical low Earth orbit satellites. All six cluster satellites were successfully launched by a single Minotaur launch vehicle on April 15, 2006. The retrieved global positioning system (GPS) radio occultation (RO) data have been freely available online to the science community since shortly after the completion of satellite bus in-orbit checkout. Having completed the verification and validation, the worldwide science communities are highly satisfied with the RO data. Scientists have hailed the RO sensors as offering the most accurate, precise, and stable thermometers in space. After one year in orbit, all six FORMOSAT-3/COSMIC satellites were in good condition (except FM2, which had power shortage issues) and were on their way toward the final constellation of six separate orbit planes with 30 degrees separation. Four out of six satellites had already reached their final mission orbit of 800 kin by mid-May 2007. Together, the six satellites have generated a total of more than 2500 RO data per day. However, only 50%-70% of the RO data as received one year after launch could be retrieved into useful atmosphere profiles. The retrieved RO data, about 1800 per day on average, have been assimilated into numerical weather prediction models by many major weather forecast centers and research institutes. This paper provides an overview of the constellation mission, the spacecraft system performance after one year in orbit, the technical challenges we have encountered, and the performance enhancements we have accomplished.
FORMOSAT-3/COSMIC Spacecraft Constellation System, Mission Results, and Prospect for Follow-On Mission
(2009-02-01)
Fong, Chen-Joe
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Yen, Nick L.
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Chu, Chung-Huei
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Yang, Shan-Kuo
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Shiau, Wen-Tzong
The FORMOSAT-3/COSMIC spacecraft constellation consisting of six LEO satellites is the world's first operational GPS Radio Occultation (RO) mission. The mission is jointly developed by Taiwan's National Space Organization (NSPO) and the United States' UCAR in collaboration with NSF, USAF, NOAA, NASA, NASA's Jet Propulsion Laboratory, and the US Naval Research Laboratory. The FORMOSAT-3/COSMIC satellites were successfully launched from Vandenberg US AFB in California at 0 140 UTC 15 April 2006 into the same orbit plane of the designated 516 km altitude. The mission goal is to deploy the six satellites into six orbit planes at 800 kin altitude with a 30-degree separation for evenly distributed global coverage. All six FORMOSAT-3/COSMIC satellites are currently maintaining a satisfactory good state-of-health. Five out of six satellites have reached their final mission orbit of 800 kin as of November 2007. The data as received by FORMOSAT-3/COSMIC satellites constellation have been processed in near real time into 2500 good ionospheric profiles and 1800 good atmospheric profiles per day. These have outnumbered the worldwide radiosondes (similar to 900 mostly over land) launched from the ground per day. The processed atmospheric RO data have been assimilated into the Numerical Weather Prediction (NWP) models for real-time weather prediction and typhoon/hurricane forecasting by many major weather centers in the world. This paper describes the FORMOSAT-3/COSMIC satellite constellation system performance and the mission results that span the period from April 2006 to October 2007; and reviews the prospect of a future follow-on mission.
Mission Results from FORMOSAT-3/COSMIC Constellation System
(2008-11-01)
Fong, Chen-Joe
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Huang, Cheng-Yung
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Chu, Vicky
;
Yen, Nick
;
Kuo, Ying-Hwa
The FORMOSAT-3/COSMIC spacecraft constellation consisting of six low-Earth-orbit satellites is the world's first operational Global Positioning System radio occultation mission. Its mission is jointly developed by Taiwan's National Space Organization and the United States's University Corporation for Atmospheric Research in collaboration with NASA's Jet Propulsion Laboratory and the Naval Research Laboratory for the three onboard payloads, which include the Global Positioning System occultation receiver, the triband beacon, and the tiny ionospheric photometer. The FORMOSAT-3/COSMIC mission was launched successfully from Vandenberg Air Force Base on 15 April 2006 into the same orbit plane of the designated 516 km circular parking orbit altitude. All six FORMOSAT-3/COSMIC satellites are maintained in a good state of health except spacecraft flight model 2, which has a power shortage, and flight model 3, currently staying at an orbit of 711 km due to a mechanism problem to be solved, and are on their way toward the final constellation of six separate orbit planes with 30 deg separations as planned. Five out of six satellites have reached their final mission orbit of 800 km as of November 2007. The FORMOSAT-3/COSMIC has processed over 1800 good atmospheric sounding profiles per day on average, which is larger than the number of worldwide radiosondes launched per day (similar to 900, mostly above the land). The atmospheric radio occultation sounding data are assimilated into the numerical weather prediction models for real-time weather prediction and typhoon/hurricane forecast. The global and some major nations' weather prediction centers have shown a significant positive impact and the forecast result will be also adapted to Taiwan's disaster warning and relief system once constellation deployment is completed by the end of 2007. With the invention of the open-loop technique by University Corporation for Atmospheric Research, the quality, accuracy, and lowest penetration altitude of the radio occultation sounding profiles are better than CHAMP data. This paper also describes the mission highlight, the constellation spacecraft system performance summary, the constellation mission operation result, and the mission science results.