Russian Scientists Discover How to Harness Chaos for Spacecraft Control
© Photo : Russian space agency Roscosmos
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Conventional scientific methods are limited in their ability to predict the behavior of complex dynamic systems over extended periods. For instance, weather forecasts typically cannot provide detailed predictions beyond 14 days. This unpredictable nature of systems is referred to as "chaos."
Researchers from Samara National Research University in Russia have proposed an innovative approach to controlling spacecraft using chaos theory. They believe this breakthrough could enhance the orientation of spacecraft in space. The findings were published in the esteemed journal Nonlinear Dynamics.
Pioneering American mathematician and meteorologist Edward Norton Lorenz was a key figure in the study of dynamic chaos. He identified a critical characteristic of chaotic systems and revealed that they are influenced by "strange chaotic attractors." These attractors are subsets of the phase space that draw all trajectories originating nearby over time.
In essence, diverse systems—ranging from atmospheric convection and nonlinear oscillations in various electrical and mechanical devices to the human heartbeat—exhibit intricate oscillatory processes. The laws governing these oscillations are continuously changing yet remain confined within specific limits, explains Anton Doroshin, head of the Department of Theoretical Mechanics at Samara University.
"Such oscillations never repeat themselves, and their graphs appear to the human eye as random signals with continuously varying amplitude and frequency. This instability arises because these oscillations persistently 'escape' from their neighboring modes. Nevertheless, they remain within a limited region of space, attracted to a strange attractor—a complex geometric entity with fractional dimensionality known as a fractal," he elaborated.
While the effects of chaos on dynamical systems are often perceived as detrimental—prompting many scientists to focus on identifying, preventing, and mitigating chaotic behavior—there is a growing body of research that recognizes chaos as a potentially beneficial phenomenon.
"The authors of certain studies have proposed chaotic trajectories for spacecraft traveling from Earth to lunar orbit, achieving more efficient fuel consumption than traditional pulsed GOMAN flights. They explored chaotic options for correcting erroneous flight paths resulting from launch-stage mistakes and showcased examples of successful missions salvaged by entering a chaotic regime—such as the Japanese Hiten lunar exploration spacecraft and the American HGS-1 communications satellite," said co-author Nikolay Elisov, a senior researcher at Samara University.
By employing a differential evolution algorithm, the researchers optimized the process of chaotic reorientation for spacecraft, enabling them to achieve the desired angular position while simultaneously reducing rotational speed.
"We synthesized the spatial reorientation of a spacecraft through the creation of dynamic chaos in its angular motion. To initiate this chaos, we utilized both established strange chaotic attractors and new ones we discovered, each capable of entrapping the spacecraft's motion in dynamic chaos. With our optimization algorithm, we determined the optimal timing to exit the chaotic regime and achieve a specified orientation in space with minimal residual angular velocity," summarized Doroshin.
The research team plans to continue investigating the fundamental properties of deterministic chaos and its advantageous applications, particularly in the realms of space mechanics and astrodynamics. This study was supported by a grant from the Russian Science Foundation (RSF).
