The communications link in a space program is a crucial point for upgrading its performance by handling data between spacecraft bus and payloads, because spacecraft’s missions are related to the data handling mechanism using communications ports such as a controlled area network bus (CAN Bus) and a universal asynchronous receiver and transmitter (UART). The NEXTSat-1 has a lot of communications ports for performing science and technology missions. However, the top level system requirements for the NEXTSat-1 are mass and volume limitations. Normally, the communications for units shall be conducted by using point to point link which require more mass and volume to interconnect. Thus, our approach for the novel communications link in the NEXTSat-1 program is to use CAN and serializer and deserializer low voltage differential signal (SerDesLVDS) to meet the system requirements of mass and volume. The CAN Bus and SerDesLVDS were confirmed by using already defined communications link for our missions in the NEXTSat-1 program and the analysis results were reported in this study in view of data flow and size analysis.

1. INTRODUCTION
 2. SYSTEM CONFIGURATION
 3. COMMUNICATIONS PORTS
  3.1 Link Applications and Requirements for Subsystems
  3.2 Size of SoH and Mission Data Being Generated
  3.3 Link Design and Performance Check
 4. RESULTS AND DISCUSSION
 5. CONCLUSIONS
 ACKNOWLEDGEMENTS
 REFERENCES

• Goo-Hwan Shin(Satellite Technology Research Center, Korea Advanced Institute of Science and Technology) Corresponding Author
• Jang-Soo Chae(Satellite Technology Research Center, Korea Advanced Institute of Science and Technology)
• Kyung-Wook Min(Department of Physics, Korea Advanced Institute of Science and Technology)
• Jong-Dae Sohn(Department of Physics, Korea Advanced Institute of Science and Technology)
• Woong-Seob Jeong(Korea Astronomy and Space Science Institute)
• Dae-Hee Lee(Korea Astronomy and Space Science Institute)