Neural Network-Based Optimization of LEO Transfers

This study investigates the application of neural networks to the evaluation of minimum-time low-thrust transfers in low Earth orbit. The findings demonstrate the effectiveness of utilizing costates to regularize the training loss, significantly enhancing the accuracy of the predictions of the neural networks, even when working with limited datasets. Remarkably precise estimates of transfer times are achieved by training the regularized networks on datasets comprising one million samples. The incorporation of a warm-started guess strategy, involving simpler neural networks to provide transfer time and costates predictions for new transfers, accelerates the data collection process, making this approach highly practical for real-world applications. Overall, the methodology employed in this research study holds significant promise for low-thrust space missions, particularly when the evaluation of multiple minimum-time transfers is necessary in mission planning. In fact, the trained neural networks significantly speed up convergence when solving optimal control problems with indirect optimization methods. Furthermore, the remarkable accuracy in estimating both minimum transfer times and costates provides the flexibility of relying entirely on neural networks for determining minimum time.