Session
Swifty Session 1
Abstract
Many spacecraft have brief ground station contact time. Consequently, high data rate is the key to mission success. Since data transmission rate is proportional to transmitter power, the reliable generation of power enters the return on investment (ROI) equation. Therefore, most spacecraft trade analyses consider several solar array designs. This paper presents an approach for evaluating the data rate potential of five solar array system options. A CubeSat (10cmonedge) example is used to demonstrate the approach. The Cube Sat is fixed to an LVLH reference frame with five sides available for solar cells. The sixth side is Earth oriented and dedicated to the payload and data antennas. Realistic electrical power and communication system models provide a data rate coefficient as a function of solar direction cosines. Relationships are developed for the direction cosines as a function solar beta angle and panel deployment angles. Data rates are estimated for five solar array options. It is shown that data rate increases with respect to body fixed panels of 55% and 60% are achievable. The impact of higher data rates on other sub systems is discussed. Selection of the best configuration requires customer/designer evaluation of total ROI considering cost and reliability
Spacecraft System Options for Best Data Rate
Many spacecraft have brief ground station contact time. Consequently, high data rate is the key to mission success. Since data transmission rate is proportional to transmitter power, the reliable generation of power enters the return on investment (ROI) equation. Therefore, most spacecraft trade analyses consider several solar array designs. This paper presents an approach for evaluating the data rate potential of five solar array system options. A CubeSat (10cmonedge) example is used to demonstrate the approach. The Cube Sat is fixed to an LVLH reference frame with five sides available for solar cells. The sixth side is Earth oriented and dedicated to the payload and data antennas. Realistic electrical power and communication system models provide a data rate coefficient as a function of solar direction cosines. Relationships are developed for the direction cosines as a function solar beta angle and panel deployment angles. Data rates are estimated for five solar array options. It is shown that data rate increases with respect to body fixed panels of 55% and 60% are achievable. The impact of higher data rates on other sub systems is discussed. Selection of the best configuration requires customer/designer evaluation of total ROI considering cost and reliability
