System-level verification and validation
The EXTREMA Simulation Hub (ESH) is DART's integrated environment for testing autonomous Guidance, Navigation, and Control (GNC) systems for deep-space missions. Several specialized hardware-in-the-loop (HIL) modules operate as one system with numerical simulation, onboard-computing emulation, data exchange, and experiment monitoring.
Navigation estimates, guidance commands, actuation measurements, attitude motion, and propagated spacecraft dynamics interact in a closed loop. A test can exercise this coupled behavior across an autonomous mission scenario.
Integrated modules
RETINA provides the optical stimulation chain for a real camera. It presents the scene associated with the simulated spacecraft state and returns the acquired images to the navigation software. ETHILE places a physical thrust and measurement chain between guidance and control commands and the simulated dynamics. STASIS uses a spherical air-bearing platform to reproduce near-frictionless three-axis attitude motion for attitude determination and control experiments.
ELAPSE, the EXTREMA fLAtsat Processing SystEm, provides the FlatSat computing and software environment. It runs autonomous navigation, guidance, and control applications in an onboard-computer-like context and connects them to the other ESH modules.
Simulation and monitoring infrastructure
High-fidelity numerical simulation coordinates the physical modules. SPESI propagates the simulated spacecraft state and associated quantities while keeping the HIL experiment synchronized. MoniCA monitors and controls the connected devices. Within ESH, both provide shared simulation and monitoring infrastructure.
Applications
ESH supports processor-in-the-loop and HIL verification and validation (V&V), periodic integration exercises, interface testing, and repeatable end-to-end experiments for autonomous interplanetary GNC. These experiments bring sensor, actuator, timing, communication, and hardware constraints into the same test.