The objective of the task is to develop a risk-aware, machine learning-based planning and decision making capabilities that will enable a spacecraft to dynamically adapt to its environment while explicitly reasoning about risk to ensure safety.
Space exploration is fundamentally about exploring the unknown. When designing spacecraft autonomy, the traditional approach is to develop a point design that works robustly for all expected situations. However, when future missions dare to explore worlds that are even more remote, the traditional approach will fail due to the large uncertainty. This challenge requires to an adaptive approach, where the autonomous spacecraft learns about the risks of its new environment, updates its internal models, and flexibly adjusts its behavior.
Take, for example, Curiosity’s unexpected slippage on a low-slope, sandy terrain. The prediction of slippage of the Mars rover is largely based on the model derived from extensive experiments on Earth. However, Curiosity has repeatedly observed excessive (up to 80%) slip on a low-slope sandy terrain, where the Earth-based model predicts only 10-20% of slip. Such a high slip posed a major risk on the mission since it may result in embedding of the rover. A slow driving speed of Curiosity allowed the ground operators to adapt to the unexpected situation. However, in a future missions with more agile and autonomous mobility and increased communication latency, on-board learning and adaptation will be essential.
While machine learning has proven useful in Earth satellite missions (e.g., scene classification), it is not considered to be ready for mission-critical applications, such as on-board activity planning, for two reasons: 1) traditional machine learning requires a significant volume of training data, while space missions require quick adaptation to new environment; 2) on-board learning may result in potentially risky behavior that cannot be checked a-priori by ground operation. Overcoming these challenges is critical for advancing the frontier of space exploration.
