Small Satellite Cluster Inter-Connectivity
Session
Pre-Conference: CubeSat Developers' Workshop
Abstract
The advances in microelectronics have made small satellite technology an effective alternative to large and expensive satellites by decreasing space mission costs, without greatly reducing the performance. Small satellites can be launched in close formation flying patterns to perform coordinated measurements of remote space missions. This will allow a cluster of small satellites to be used to collect data from multiple points and time, thereby providing spatial and temporal resolutions that cannot be achieved with a single, conventional large satellite. There are three different formation flying patterns under study; Leader-Follower (A-Train), Cluster and Constellation. Inter-satellite communication eliminates the use of expensive ground relay stations and ground tracking networks. When satellites fly in constellations, using inter-satellite communications, it’s not necessary to sink all the data from each of the small satellite to ground, thus eliminating the need of intermediate ground stations for sending data. The small satellite formation control problems, particularly, attitude and relative position can be solved using inter-satellite communication by exchanging the attitude and relative position information among the small satellites. It can also provide timing synchronization. Therefore, inter-satellite communication plays a vital role when small satellites fly in close formations. This presentation aims to propose and validate inter-satellite communication protocols for distributed small satellite networks. We investigate the possibility of implementing a feasible Medium Access Control (MAC) and routing layer protocols for the three different formation flying patterns. A modified MAC and routing protocols particularly the Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) with Request to Send/Clear to Send (RTS/CTS) protocol are analyzed. Our proposed system performance is evaluated using throughput, access delay and end-to-end delay by running extensive simulations. The throughput of the system is defined as the fraction of the total simulation time used for a valid transmission. For the Leader-Follower formation flying pattern the maximum throughput we can achieve using the proposed protocol is about 23% and for Cluster formation pattern, the maximum throughput is found to be 11%. Average access delay and end-to-end delay are less for Leader-Follower formation pattern compared to the Cluster formation flying pattern. We are currently working on the Constellation formation pattern. We have investigated the three types of formation for which we will describe the relative merits of each formation. The decision of which formation flying pattern has to be used depends on the mission architecture, e.g. number of satellites, orbits, power, etc.
Presentation Slides
Small Satellite Cluster Inter-Connectivity
The advances in microelectronics have made small satellite technology an effective alternative to large and expensive satellites by decreasing space mission costs, without greatly reducing the performance. Small satellites can be launched in close formation flying patterns to perform coordinated measurements of remote space missions. This will allow a cluster of small satellites to be used to collect data from multiple points and time, thereby providing spatial and temporal resolutions that cannot be achieved with a single, conventional large satellite. There are three different formation flying patterns under study; Leader-Follower (A-Train), Cluster and Constellation. Inter-satellite communication eliminates the use of expensive ground relay stations and ground tracking networks. When satellites fly in constellations, using inter-satellite communications, it’s not necessary to sink all the data from each of the small satellite to ground, thus eliminating the need of intermediate ground stations for sending data. The small satellite formation control problems, particularly, attitude and relative position can be solved using inter-satellite communication by exchanging the attitude and relative position information among the small satellites. It can also provide timing synchronization. Therefore, inter-satellite communication plays a vital role when small satellites fly in close formations. This presentation aims to propose and validate inter-satellite communication protocols for distributed small satellite networks. We investigate the possibility of implementing a feasible Medium Access Control (MAC) and routing layer protocols for the three different formation flying patterns. A modified MAC and routing protocols particularly the Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) with Request to Send/Clear to Send (RTS/CTS) protocol are analyzed. Our proposed system performance is evaluated using throughput, access delay and end-to-end delay by running extensive simulations. The throughput of the system is defined as the fraction of the total simulation time used for a valid transmission. For the Leader-Follower formation flying pattern the maximum throughput we can achieve using the proposed protocol is about 23% and for Cluster formation pattern, the maximum throughput is found to be 11%. Average access delay and end-to-end delay are less for Leader-Follower formation pattern compared to the Cluster formation flying pattern. We are currently working on the Constellation formation pattern. We have investigated the three types of formation for which we will describe the relative merits of each formation. The decision of which formation flying pattern has to be used depends on the mission architecture, e.g. number of satellites, orbits, power, etc.
