YuSend-1 nanosatellite communication subsystem · students. This project attempts to recreate the...
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Ground Segment For the ground segment, the tasks were divided into the assembly and connection of the physical antenna, and the software and configuration to allow the antenna to be controlled from the console, and receive data from existing satellites. For software, the ground station console uses the program UniTrak, made for the Unitrak controller that allows the antenna to change elevation and azimuth. This UniTrak program is itself controlled by a program, Nova, which maintains a list of satellites, including information on position and velocity. The ground station is able to track and receive communications from satellites in this manner. Introduction YuSend-1 is a nanosatellite currently being developed by York University under the supervision of Dr. Regina Lee. The primary objective of this project is to provide the design for a reliable communication link between YuSend-1 and the ground station. This includes transmitting telemetry and command sequences from the ground station (uplink) and receiving analog and digital data obtained from the payload and sensors onboard the Cubesat (downlink) via RF transmission. This project is responsible for the design of the Space Segment, as well as the implementation, building and testing of both the Ground Segment (GS) and Space Segment (SS) of the communication system. In the past, design of Cubesat communications systems have primarily been undertaken by graduate students. This project attempts to recreate the achievements of other Cubesat design teams within the context of an undergraduate course, having very limited time and budget. These constraints are critical when making design decisions for this project, from the selection of TNC and Transceiver hardware, to the design and implementation of the antenna. Space Segment For the space segment, there are three main components: The computer/logic to process requests and control the system, the TNC (Terminal Node Controller) to convert data to an analog waveform, and the transceiver, to transmit and receive data on specified frequencies. After researching specifications, price, and flight history, the components were chosen. The Yaesu VX-3R (Fig. 2a) would be the tranceiver in the system. It is the successor to the VX-1R and 2R, which have significant flight history in previous Cubesat missions. The TNC for the system was chosen to be the PacComm PicoPacket (Fig. 2b), because of its flight heritage, small size, low power requirements and low cost. The On-board computer functionality is met by the Linuxstamp OBC (Fig. 2c), which combines a familiar linux ARM9 architecture with small form factor and minimal power usage. In order for the system to be tested in the Thermal Vacuum chamber, they are mounted onto a metal plate (Fig. 2d), and excess plastic and extraneous parts are removed. Acknowledgments We thank our Faculty advisor Dr. Regina Lee for her tireless effort and guidance, Professor Hugh Chesser for his advice and assistance., and Professor George Zhu for direction and advice. We would like to thank the YUSDG grad students: Mark Post, Matthew Cannata, David King, Nimal Navarathinam, Ian Proper, and Kartheephan Sathiyanathan. Special thanks to Associate Professor Brendan Quine for use of the T-Vac chamber. We would also like to thank our PEO advisor Steven Coates. Results The space segment of the communication system was tested in a Thermal Vacuum chamber (T-Vac), to test operations in space conditions. Conclusions Based on this design and the results we have obtained, it is possible to build a functioning communications system for Cubesat profile satellites for under $1000. This indicates that further projects are possible at an undergraduate level, and with similar funding requirements. The VX-3R transceiver appears to be a weak point in future designs and potentially a cause for failure in previous Cubesats. It was not able to operate in vacuum conditions, due to its excessive heat. A robust cooling solution is needed for this transceiver if it is to be used in the space environment. T. Crawford, M. Hughes, D. Ketcheson, M. Kuruvilla ENG 4000 Engineering Design Project, York University, Toronto, Canada Literature cited Yaesu Inc Instructional manual Yaesu G-5500 Unknown publishing date Roddy, Dennis Satellite Communications 4th Edition, Prentice-Hall Inc, 2006 Daniel Kuester, A 2.4GHz High Speed Communications System for Cubesat Applications, Colorado University, 2007 Klofas, Bryan, A Survey of CubeSat Communication Systems (draft), California Polytechnic State University, April 18 2008 Figure 1. Project overview Figure 3. Components of the system. A) Yaesu VX-3R tranceiver. (with case removed) B) PacComm PicoPacket TNC (with case removed) C) LinuxStamp embedded computer. D) All components mounted and connected on base for testing. For further information More information on this project can be found at http://yusend.timdc.com Figure 5. The results of T-Vac testing. The two spikes of temperature are from the communication system transceiver operation. The first spike in temperature causes the transceiver to shut down. It was able to be restarted . The second time it shut down, and was not able to be started again. YuSend-1 nanosatellite communication subsystem A) Figure 2. The ground segment console, and the ground segment antenna apparatus. B) C) D) Temp (°C) Temperature of transceiver Time Figure 4. (left) The space segment, prepared for the Thermal Vacuum chamber. (right) Securing the system into the chamber for testing. Outside the T-Vac chamber, under normal conditions, the system can exchange data from ground segment to space segment using amateur radio frequencies (RF). During the testing within the T-Vac chamber, the heat generated by the transceiver is difficult to dissipate. Using a temperature sensor mounted on the transceiver for the test, large increases in temperature were detected during transmission of data. Several transfers were made successfully, and then the temperature reached a point where the transceiver shuts down. After two such failures, both occurring at 65 degrees. After the first failure, the transceiver was power down and successfully restarted. However, after a second failure, the device was not recoverable. Figure 6., Using the Ground Station console to receive satellite communications Ground Segment Space Segment OBC TNC Transceiver Antenna PC TNC Transceiver Antenna Rx Tx Rx Tx Rx Tx Rx Tx
Transcript of YuSend-1 nanosatellite communication subsystem · students. This project attempts to recreate the...
Ground SegmentFor the ground segment, the tasks were divided into the assembly and connection of the physical antenna, and the software and configuration to allow the antenna to be controlled from the console, and receive data from existing satellites.
For software, the ground station console uses the program UniTrak, made for the Unitrak controller that allows the antenna to change elevation and azimuth. This UniTrak program is itself controlled by a program, Nova, which maintains a list of satellites, including information on position and velocity.
The ground station is able to track and receive communications from satellites in this manner.
IntroductionYuSend-1 is a nanosatellite currently being developed by York University under the supervision of Dr. Regina Lee. The primary objective of this project is to provide the design for a reliable communication link between YuSend-1 and the ground station. This includes transmitting telemetry and command sequences from the ground station (uplink) and receiving analog and digital data obtained from the payload and sensors onboard the Cubesat (downlink) via RF transmission. This project is responsible for the design of the Space Segment, as well as the implementation, building and testing of both the Ground Segment (GS) and Space Segment (SS) of the communication system.
In the past, design of Cubesat communications systems have primarily been undertaken by graduate students. This project attempts to recreate the achievements of other Cubesat design teams within the context of an undergraduate course, having very limited time and budget. These constraints are critical when making design decisions for this project, from the selection of TNC and Transceiver hardware, to the design and implementation of the antenna.
Space SegmentFor the space segment, there are three main components: The computer/logic to process requests and control the system, the TNC (Terminal Node Controller) to convert data to an analog waveform, and the transceiver, to transmit and receive data on specified frequencies.
After researching specifications, price, and flight history, the components were chosen. The Yaesu VX-3R (Fig. 2a) would be the tranceiver in the system. It is the successor to the VX-1R and 2R, which have significant flight history in previous Cubesat missions. The TNC for the system was chosen to be the PacComm PicoPacket (Fig. 2b), because of its flight heritage, small size, low power requirements and low cost. The On-board computer functionality is met by the Linuxstamp OBC (Fig. 2c), which combines a familiar linux ARM9 architecture with small form factor and minimal power usage.
In order for the system to be tested in the Thermal Vacuum chamber, they are mounted onto a metal plate (Fig. 2d), and excess plastic and extraneous parts are removed.
AcknowledgmentsWe thank our Faculty advisor Dr. Regina Lee for her tireless effort and guidance, Professor Hugh Chesser for his advice and assistance., and Professor George Zhu for direction and advice. We would like to thank the YUSDG grad students: Mark Post, Matthew Cannata, David King, Nimal Navarathinam, Ian Proper, and KartheephanSathiyanathan. Special thanks to Associate Professor Brendan Quinefor use of the T-Vac chamber. We would also like to thank our PEO advisor Steven Coates.
ResultsThe space segment of the communication system was tested in a Thermal Vacuum chamber (T-Vac), to test operations in space conditions.
ConclusionsBased on this design and the results we have
obtained, it is possible to build a functioning communications system for Cubesat profile satellites for under $1000. This indicates that further projects are possible at an undergraduate level, and with similar funding requirements.
The VX-3R transceiver appears to be a weak point in future designs and potentially a cause for failure in previous Cubesats. It was not able to operate in vacuum conditions, due to its excessive heat. A robust cooling solution is needed for this transceiver if it is to be used in the space environment.
T. Crawford, M. Hughes, D. Ketcheson, M. KuruvillaENG 4000 Engineering Design Project, York University, Toronto, Canada
Literature citedYaesu Inc Instructional manual Yaesu G-5500 Unknown publishing
dateRoddy, Dennis Satellite Communications 4th Edition, Prentice-Hall
Inc, 2006Daniel Kuester, A 2.4GHz High Speed Communications System for
Cubesat Applications, Colorado University, 2007Klofas, Bryan, A Survey of CubeSat Communication Systems (draft),
California Polytechnic State University, April 18 2008
Figure 1. Project overview
Figure 3. Components of the system. A) Yaesu VX-3R tranceiver. (with case removed) B) PacComm PicoPacket TNC (with case removed) C) LinuxStamp embedded computer. D) All components mounted and connected on base for testing.
For further informationMore information on this project can be found at http://yusend.timdc.com
Figure 5. The results of T-Vac testing. The two spikes of temperature are from the communication system transceiver operation. The first spike in temperature causes the transceiverto shut down. It was able to be restarted . The second time it shut down, and was not able to be started again.
YuSend-1 nanosatellite communication subsystem
A)
Figure 2. The ground segment console, and the ground segment antenna apparatus.
B) C)
D)
Temp(°C)
Temperature of transceiver
Time
Figure 4. (left) The space segment, prepared for the Thermal Vacuum chamber. (right) Securing the system into the chamber for testing.
Outside the T-Vac chamber, under normal conditions, the system can exchange data from ground segment to space segment using amateur radio frequencies (RF).
During the testing within the T-Vac chamber, the heat generated by the transceiver is difficult to dissipate. Using a temperature sensor mounted on the transceiver for the test, large increases in temperature were detected during transmission of data. Several transfers were made successfully, and then the temperature reached a point where the transceiver shuts down. After two such failures, both occurring at 65 degrees. After the first failure, the transceiver was power down and successfully restarted. However, after a second failure, the device was not recoverable.
Figure 6., Using the Ground Station console to receive satellite communications
Ground Segment
Space Segment
OBC TNC Transceiver Antenna
PC TNC Transceiver Antenna
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
