Portal:Concept Studies/Spacecraft Autonomy
From TeamFrednetWiki
The purpose of this article is to describe spacecraft autonomy in relation to mission and system dependencies.
Maximizing autonomy, subject to mass, reliability and feasibility, results in simpler requirements for ground stations and ground support systems, and a higher degree of assurance of total mission sucess.
Classes of autonomy include
- Completely autonomous
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- Autonomous orbital determination
- Interaction from ground on a high level of abstraction, in inertial coordinate frame, etc
- Highly autonomous
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- Interaction from ground on a high level of abstraction, in inertial coordinate frame, etc
- A collection of S/C systems that maintain a large, distributed S/C state vector
- Simple autonomy
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- Interaction in S/C relative terms
- A simpler S/C state vector shared among simpler systems
- No autonomy
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- Fly by wire
- The S/C doesn't maintain a real state vector
Due to communications delays, the general scarcity of bandwidth, and the general level of system and human complexity that is the terrestrial network of ground stations and their operation, we need a high degree of autonomy coupled with minimizing the consumption of both bandwidth and packet message count.
Considering this, we need to design for flying by TM/TC exclusively. The more compact and effective these most essential operations are, the more reliable our operations will be.
The cost of simple autonomy would be to essentially push the mission flight control problem away from the spacecraft where it's most assured, and onto communications and support systems which then become more critical and more complex.
We really need a highly autonomous flight control system. Ideally one completely autonomous. There's some evidence that it's possible. One possible approach to this problem is a described in "Decision-Making in Embedded Reasoning System" [1].
In the completely autonomous case, mission assurance is maximized as its dependence on the ground stations' network is minimized. And, ground support systems and operating procedures are substantially simplified.
