Autonomous Guidance & Control of Earth-Orbiting Formation Flying Spacecraft
- Paper number
IAC-06-C1.7.01
- Author
Mr. Jean-Francois Hamel, Universite de Sherbrooke, Canada
- Coauthor
Dr. Jean de Lafontaine, NGC Aerospace Ltd., Canada
- Year
2006
- Abstract
Formation flying of spacecraft has been identified a key technology for the 21 st century. There is a trend toward replacing large expensive spacecraft by a group of smaller and cheaper spacecraft. Two of the main advantages of formation flying are reconfigurability and an increased robustness to system failures. The main drawback of formation flying spacecraft is an increased complexity of the systems. This is particularly true for the guidance, navigation and control system, which complexity grows rapidly with the number of spacecraft in the formation.
There is however at the same time an increasing need for autonomy to decrease the cost of ground support. Ground support operations are a non-negligible part of the cost of a mission, especially for small and cheap scientific exploration missions. Therefore, the guidance and control system needs to perform autonomous decisions and trade-offs in real-time to decrease the tasks that need to be performed by the ground segment and make formation flying affordable. Moreover, to increase the robustness to single spacecraft failure, the guidance and control of the formation needs to be decentralized. This is all especially challenging when the number of spacecraft in the formation becomes large.
The paper shows how analytical decentralized guidance and control laws, suitable for autonomy, can be developed considering a J 2-perturbed elliptical orbit. Formation flying algorithms have to take into account several conflicting goals: mission requirements, collision avoidance, single spacecraft propellant lifetime and formation propellant lifetime. Complying with the mission requirements involves having all the spacecraft with the desired orbital elements. Increasing the lifetime of each single spacecraft is reached through minimizing fuel consumption. Extending the lifetime of the whole formation is achieved by ensuring equal fuel consumption between all the spacecraft and by sticking to J 2-invariant non-drifting trajectories. Therefore, in some cases some mission requirements must be relaxed in order to avoid an excessive fuel consumption. The guidance and control algorithms take into account all the conflicting goals to provide ways of autonomously reconfiguring a formation and recovering from spacecraft failure.
- Abstract document
- Manuscript document
IAC-06-C1.7.01.pdf (🔒 authorized access only).
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