• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.1
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• pp.110-115
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• 2006

STSAT-2 is the first satellite which will be launched by the first Korean Space Launch Vehicle(KSLV). Ground station Baseband Control system(GBC) is now developed for STSAT-2. GBC has two functions. One is control data path between satellite control computers and ground station antennas(1.5M, 3.7M, 13M) automatically. The other is sending and receiving data between ground station and satellite. GBC is implemented by FPGA(Field-Programmable Gate Array) which includes almost all logic(for MODEM, PROTOCOL and GBC system control). MODEM in GBC has two uplink FSK modulators(1.2[kbps], 9.6[kbps]) and six downlink FSK demodulators(9.6[kbps], 38.4[kbps]). In hardware, STSAT-2 GBC is smaller than STSAT-1 GBC. In function, STSAT-2 GBC has more features than STSAT-1 GBC. This paper is about GBC structure, functions and test results.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.293-295
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• 2004

The Engineering Model of on-board computer was developed and tested completely with other sub-systems for STSAT-2. We designed the on-board computer of STSAT-2 which has some improved features compared with that of STSAT-l. A remarkable change is that the on-board computer has a structure of centeralized network communication without a Network Controller of the STSAT-l. That is, the on-board computer directly manages a satellite network. In addition, as many logics are implemented by Field Programmable Gate Array, so we can reduce the weight and size of on-board computer. Also, the developed on-board computer has more improved tolerance against Single Event Upsets and faults than that of the STSAT-l.

• Bulletin of the Korean Space Science Society
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• 2006.04a
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• pp.92-92
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• 2006

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.5
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• pp.93-98
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• 2005

An Engineering Model(EM) of the Telemetry-Command Unit(TCU) for STSAT-2 was developed. The TCU of STSAT-2 has some improved features compared with that of STSAT-1. To reduce weight and size of TCU all logics are implemented in FPGA without CPU. EM I&T(Integration and Test) was successfully performed with no errors.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.2
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• pp.195-201
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• 2008

This paper compares the performance of Mass Memory Unit(MMU) between Science and Technology Satellite 1(STSAT-1) and STSAT-2 from developed Proto Flight Model(PFM) for Miniaturization, lightweight and low power consumption. MMU receives the payload data at 200Kbps and transmits them to XTX at 10Mbps in the STSAT-2. The performance of PFM MMU in the Functional and space environments test satisfies the requirements of STSAT-2.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.101-105
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• 2006

The Engineering Model of STSAT-2 on-board computer(OBC) was developed and tested completely with other sub-systems. The on-board computer of STSAT-2 has a high- performance PowerPC processors and a structure of centralized network communication. In addition, a lot of logics are implemented by Field Programmable Gate Array, such as interrupt controller, watchdog timer and UART. It could make the weight and size of OBC lighter and smaller. Also, the STSAT-2 on-board computer has more improved tolerance against Single Event Upsets and faults than that of the STSAT-1.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.8
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• pp.482-485
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• 2005

STSAT-2 is first satellite which is scheduled to launch by first Korea launcher. Ground station Baseband Controller(GBC) for operating STSAT-2 is now developing. GBC control data flow path between satellite operation computers and ground station antennas and count number of received data packets among demodulated audio signals from three antennas and also set data flow path to good-receiving antenna automatically In GBC two uplink FSK modulators(1.2kbps, 9.6kbps) and six downlink FSK demodulators(9.6kbps, 38.4kbps) are embedded. STSAT-2 GBC hardware is more simpler than STSAT-1 GBC by using FPGA in which all digital logic implemented. Now test and debugging of GBC hardware and Software(FPGA Code and CBC Manager Program) is well progressing in SaTReC, KAIST. This paper introduce GBC structure, functions and test results.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.116-118
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• 2005

STSAT-2 is first satellite which is scheduled to launch by first Korea launcher. After launch Ground station Baseband Controller(GBC) for operating STSAT-2 is now developing. GBC control data flow path between satellite operation computers and ground station antennas. and GBC count number of received data packets among demodulated audio signals from three antennas and set data flow path to good-receiving antenna automatically. In GBC two uplink FSK modulators(1.2kbps, 9.6kbps) and six downlink FSK demodulators(9.6kbps, 38.4kbps) are embedded. STSAT-2 GBC hardware is more simpler than STSAT-1 GBC by using FPGA in which all digital logic implemented. Now test and debugging of GBC hardware and Software(FPGA Code and GBC Manager Program) is well progressing in SaTReC, KAIST. This paper introduce GBC structure, functions and test results.

• Journal of Astronomy and Space Sciences
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• v.32 no.3
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• pp.189-200
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• 2015

In this study, we present the results of orbit determination (OD) using satellite laser ranging (SLR) data for the Science and Technology Satellite (STSAT)-2C by a short-arc analysis. For SLR data processing, the NASA/GSFC GEODYN II software with one year (2013/04 - 2014/04) of normal point observations is used. As there is only an extremely small quantity of SLR observations of STSAT-2C and they are sparsely distribution, the selection of the arc length and the estimation intervals for the atmospheric drag coefficients and the empirical acceleration parameters was made on an arc-to-arc basis. For orbit quality assessment, the post-fit residuals of each short-arc and orbit overlaps of arcs are investigated. The OD results show that the weighted root mean square post-fit residuals of short-arcs are less than 1 cm, and the average 1-day orbit overlaps are superior to 50/600/900 m for the radial/cross-track/along-track components. These results demonstrate that OD for STSAT-2C was successfully achieved with cm-level range precision. However its orbit quality did not reach the same level due to the availability of few and sparse measurement conditions. From a mission analysis viewpoint, obtaining the results of OD for STSAT-2C is significant for generating enhanced orbit predictions for more frequent tracking.

• Aerospace Engineering and Technology
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• v.10 no.2
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• pp.29-36
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• 2011

The Science and Technology Satellite-3 (STSAT-3) is based on the KITSAT-1, 2, 3 and STSAT-1, 2 which were Korea micro-satellites for the mission of space and earth science. The objectives of the STSAT-3 are to support earth and space sciences in parallel with the demonstration of spacecraft technology. The STSAT-3 carries an infrared (IR) camera for space & earth observation and an imaging spectrometer for earth observation. The IR payload instrument of the STSAT-3, Multi-purpose Infrared Imaging System (MIRIS), will observe the Galactic plane and North/South Ecliptic poles to research the origin of universe. The secondary payload instrument, Compact Imaging Spectrometer (COMIS), images the Earth's surface. The data acquired from COMIS are expected to be used for various application fields such as monitoring of disaster management, water quality studies, and farmland assessment. In this paper we present the operations concept of STSAT-3 which will be launched into a sun-synchronous orbit at a nominal altitude of 600km in late 2012.