Reproducing spacecraft attitude motion
STASIS, the SpacecrafT Attitude SImulation System, is DART's hardware-in-the-loop (HIL) platform for spacecraft attitude testing. It reproduces the rotational dynamics of a space probe on the ground, allowing attitude determination and control functions to operate with physical motion and representative onboard hardware.
The platform is supported by a spherical air bearing. A thin film of air carries the rotating assembly and reduces friction, allowing near-free motion around three rotational degrees of freedom. The platform's physical attitude becomes part of the experiment.
Closed-loop attitude experiments
Sensors observe the platform state, while onboard control functions process the measurements and command representative actuators. The resulting motion can be measured by an independent ground-truth system and compared with the estimated state and requested maneuver. Balancing, state estimation, power, communication, and safe operating limits are part of preparing a repeatable test.
Role in the EXTREMA Simulation Hub
Within the EXTREMA Simulation Hub (ESH), STASIS provides physical attitude dynamics. It can receive control commands from the integrated onboard-computing environment and return measured orientation information to the broader simulation. The resulting attitude behavior interacts with optical sensing, guidance, translational actuation, and numerically propagated mission dynamics.
Typical uses include attitude determination and control validation, estimator assessment against ground truth, actuator-response testing, interface checks, and integrated autonomous Guidance, Navigation, and Control (GNC) experiments.