TY - GEN
T1 - Vehicle and mission design options for very low earth orbit cubesats
AU - Williams, James W.
AU - Gray, Michael I.
AU - Putnam, Zachary R.
N1 - Publisher Copyright:
© 2020, Univelt Inc. All rights reserved.
PY - 2020
Y1 - 2020
N2 - Aerodynamics provide a small but significant effect on the dynamics of vehicles operating in low Earth orbit, especially CubeSats with limited control authority. Current analysis tools treat the translational and attitude dynamics of these vehicles in a decoupled sense. A coupling of these effects provides a more holistic view of the problem. In this work, various control system and physical properties of CubeSats are compared based on metrics of detumble time, total mission lifetime, and ram-pointing effectiveness. The control systems used are a magne-torquer with either a simplified Bcross detumble algorithm or a Quaternion Rate Feedback (QRF) pointing algorithm, or a set of reaction wheels using QRF. The physical properties examined are the total available control effort, the initial apoapsis of the orbit, the duty cycle of the control system, and the percent of eclipse in which control is active. Results indicate that a vehicle equipped with the Bcross algorithm will have limited pointing performance which limits the mission lifetime, while reaction wheels using QRF are capable of asymptotic stability around the ram direction, and magnetorquers using the same algorithm are able to provide nearly the same total mission duration, at a cost of worse pointing acquisition time.
AB - Aerodynamics provide a small but significant effect on the dynamics of vehicles operating in low Earth orbit, especially CubeSats with limited control authority. Current analysis tools treat the translational and attitude dynamics of these vehicles in a decoupled sense. A coupling of these effects provides a more holistic view of the problem. In this work, various control system and physical properties of CubeSats are compared based on metrics of detumble time, total mission lifetime, and ram-pointing effectiveness. The control systems used are a magne-torquer with either a simplified Bcross detumble algorithm or a Quaternion Rate Feedback (QRF) pointing algorithm, or a set of reaction wheels using QRF. The physical properties examined are the total available control effort, the initial apoapsis of the orbit, the duty cycle of the control system, and the percent of eclipse in which control is active. Results indicate that a vehicle equipped with the Bcross algorithm will have limited pointing performance which limits the mission lifetime, while reaction wheels using QRF are capable of asymptotic stability around the ram direction, and magnetorquers using the same algorithm are able to provide nearly the same total mission duration, at a cost of worse pointing acquisition time.
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M3 - Conference contribution
AN - SCOPUS:85096475846
SN - 9780877036654
T3 - Advances in the Astronautical Sciences
SP - 133
EP - 151
BT - AAS/AIAA Astrodynamics Specialist Conference, 2019
A2 - Horneman, Kenneth R.
A2 - Scott, Christopher
A2 - Hansen, Brian W.
A2 - Hussein, Islam I.
PB - Univelt Inc.
T2 - AAS/AIAA Astrodynamics Specialist Conference, 2019
Y2 - 11 August 2019 through 15 August 2019
ER -