Projects:2014S1-56 Inter-Satellite Links for CubeSats

QB50 is a project consisting of 50 international double and tripe CubeSats. The CubeSats will have various scientific instruments on board to carry out atmospheric research within the lower thermosphere, between 200 - 380km altitude, which is the least explored layer of the atmosphere. There will be 3 sets of scientific equipment onboard that will be used for the research. Another purpose of the project is to study the atmospheric re-entry process.

Project information

Our project aim is to design and implement intersatellite linking between satellites. In other terms this is passing information from one satellite to another until it hits the destination satellite which is in contact with the targeted ground station.

Since a CubeSat is only 30x10x10 cm satellite there are constraints that need to be considered such as:

• Wireless space links having high bit error rates
• Low power budget
• String of pearls constellation

The project will be using the MSP430 microcontroller range from Texas Instruments due to there low power outputs that will allow the low power budget to be achievable. The radio frequency chip that will be used is also made by Texas Instruments called the CC1120. This was chosen since it was easy to write software for the microcontroller and RF chip to communicate with each other. Also the RF chip has packet handling capabilities to combat the effect of high bit error rates.

Work Breakdown

The work has been broken down so that both are able to work on the project concurrently whilst in the end being able to integrate there software.

Robert Bulfon

• Design and Implementation of networking protocol
  • Random multiple access
  • Packet handling
• Design and Implementation of routing protocol
  • Routing table population
  • Choose shortest jump path

Troy Maylin

• Design and Implementation of wireless link
  • Create packet
  • Transmission of packets
  • Receiving of packets

Project Status

• Wireless link functional
• Networking protocol functional
• Routing protocol partially functional

Future

There are currently parts to the project that are unfinished such as the routing protocol and power management of the network. Also increasing the efficiency of the networking protocol could be implemented since at the moment it uses random multiple access whereas a more efficient method such as time division multiple access could be implemented.

Significant progress has been completed in the other aspects of the project and can be built on in the future.

Team

Group members

• Mr Robert Bulfon
• Mr Troy Maylin

Supervisors

• Associate Professor Michael Liebelt
• Prof. William Cowley

Resources

• MSP430F2410
• MSP430G2
• CC1120
• Code Composer Studio
• MSPDebug
• MSPGCC
• UART to USB serial interface
• PC
• DC power supply