Per the Principal Investigator: in coordination with the NASA Human Research Program, the research team has successfully modified its original proposal to more extensively and precisely define the countermeasure intervention that would be triggered by its spatial disorientation algorithm. See the Task Progress section for additional information. [Ed., 11/6/24.]

During transit in microgravity, astronauts will reinterpret neurovestibular stimuli, prior to initial exposure to partial gravity when landing on the Moon or Mars. This poses a risk of spatial disorientation and impaired manual control performance during piloted planetary landings. Here, we propose to develop, validate, and assess a system for detecting when astronauts may become disoriented in real-time, such that it can be used to trigger active countermeasures for piloted planetary landings. Our approach leverages a well-validated computational model for human spatial orientation, now applied to partial gravity planetary landings. Incorporating microgravity neurovestibular adaptation, the vehicle motions of each landing trajectory are processed in real-time by the computational model to detect pilot spatial disorientation. We will assess the system using a ground-based lunar landing analog, combining a gravity transition (3 Gx) with a motion-based planetary landing simulation. First, we will experimentally tune and re-validate the computational model for detecting spatial disorientation, accounting for the effects of the recent gravity transition. Then, using the high-fidelity Disorientation Research Device, we will assess the benefit of the active countermeasure triggering system. Critically, this approach of triggering manual control countermeasures only when they are needed (i.e., when the pilot is about to be disoriented) avoids the added burden on the pilot to continuously process additional sensory information or otherwise have increased workload. We aim to deliver a validated performance support tool for triggering active countermeasures for pilot spatial disorientation during manually controlled lunar landings.

In a second experiment, we systematically quantified the intensity of spatial disorientation, following various motion profiles. Following motions (which were designed to be more or less disorienting), subjects were suddenly presented with veridical instrument display information regarding their orientation and instructed to rate the severity/intensity of their spatial disorientation. Fourteen subjects completed the experiment of nominally 50 trials of motion and spatial disorientation rating. The results have been used to refine and fit parameters within our spatial disorientation algorithm to be able to predict the severity of spatial disorientation in real-time. Using a predictive modeling approach, we found quite accurate predictions of spatial disorientation using our computational model.

In a final experiment, we will assess the efficacy of the spatial disorientation algorithm in triggering the adaptive display countermeasure during a piloted lunar landing. In two groups (control group and countermeasure group), subjects will pilot a motion-based lunar landing simulator. The control group will receive no countermeasure in order to quantify the decrements in piloting performance. In the countermeasure group, the validated algorithm for estimating spatial disorientation in real-time will trigger a countermeasure when the pilot is likely to be disoriented. This adaptive display will help the pilot become reoriented, only when it is necessary, without overburdening the pilot when they are not spatially disoriented. We will assess pilot performance, mental workload, and situation awareness. Initial testing will be performed in our laboratory in preparation for our capstone experiment in the Navy Aeromedical Research Laboratory – Dayton (NAMRU-D) Disorientation Research Device (DRD).

In this third year of the project, substantial technical, scientific, and administrative progress has been made. This project has involved extensive coordination with colleagues associated with the NASA Human Research Program, NASA Langley, and NAMRU-D in coordination for our experiment using the DRD.

Coordinating with colleagues at NASA Langley, we have successfully integrated the detailed implementation of our countermeasure adaptive display into their lunar landing simulation. We had a site visit to coordinate technical details of implementing our system (and other associated experimental needs) into their lunar-landing simulation and display environment. In addition to coordinating the countermeasure implementation, we have collaborated to design 21 unique, but similar, lunar landing scenarios (defined by initial altitudes and other parameters, followed by redesignations to specific landing sites) that will be used in our experiment at NAMRU-D. Finally, we have coordinated a data streaming protocol to enable the Langley lunar landing simulation to integrate with our system for detecting spatial disorientation in real-time.

Finally, we have extensively coordinated with colleagues at NAMRU-D regarding plans for the capstone experiments using the DRD. This has included administrative coordination, including a signed CRADA document. We have written and gained approval from the local Institutional Review Board (IRB) for our planned experiments. Finally, we have coordinated a data streaming protocol to allow for DRD motion states to integrate with our system for spatial disorientation detection in real-time. In a recent site visit at NAMRU, we were able to successfully integrate our system with the Langley simulation computer and the DRD computers, streaming data between the three systems, to successfully detect pilot spatial disorientation in real-time during pilot landings on the DRD with a test pilot. Based upon this preliminary data, we have revised our system’s parameters, demonstrating technical readiness for our planned capstone experiment on the DRD. Our system is a complete implementation to process DRD motion states, continuously simulate our observer model of spatial orientation perception, and compare those model-predicted perceptions to actual Langley lunar landing vehicle states, combined across multiple aspects (linear velocity, vehicle tilt, etc.) and all three axes to yield a continuous, unidimensional metric of spatial disorientation intensity. When the predicted spatial disorientation is too great, it triggers the display countermeasure to help reorient the pilot without requiring unnecessary or excessive burden.

Per the Principal Investigator: in coordination with the NASA Human Research Program, the research team has successfully modified its original proposal to more extensively and precisely define the countermeasure intervention that would be triggered by its spatial disorientation algorithm. See the Task Progress section for additional information. [Ed., 11/6/24.]

During transit in microgravity, astronauts will reinterpret neurovestibular stimuli, prior to initial exposure to partial gravity when landing on the Moon or Mars. This poses a risk of spatial disorientation and impaired manual control performance during piloted planetary landings. Here, we propose to develop, validate, and assess a system for detecting when astronauts may become disoriented in real-time, such that it can be used to trigger active countermeasures for piloted planetary landings. Our approach leverages a well-validated computational model for human spatial orientation, now applied to partial gravity planetary landings. Incorporating microgravity neurovestibular adaptation, the vehicle motions of each landing trajectory are processed in real-time by the computational model to detect pilot spatial disorientation. We will assess the system using a ground-based lunar landing analog, combining a gravity transition (3 Gx) with a motion-based planetary landing simulation. First, we will experimentally tune and re-validate the computational model for detecting spatial disorientation, accounting for the effects of the recent gravity transition. Then, using the high-fidelity Disorientation Research Device, we will assess the benefit of the active countermeasure triggering system. Critically, this approach of triggering manual control countermeasures only when they are needed (i.e., when the pilot is about to be disoriented) avoids the added burden on the pilot to continuously process additional sensory information or otherwise have increased workload. We aim to deliver a validated performance support tool for triggering active countermeasures for pilot spatial disorientation during manually controlled lunar landings.

Our plan, the modification of the original proposal, was submitted to and approved by the NASA Human Research Program management team. The primary approach is for an adaptive display, which enhances the saliency (visual and auditory) of vehicle attitude and motion information in real-time based upon the spatial disorientation algorithm. Specifically, only when the algorithm deems the astronaut pilot is likely to be spatially disoriented does it automatically increase the saliency of critical information on the instrumentation display regarding vehicle attitude (roll and pitch) and motion to help the pilot reorient themselves in order to improve piloting performance and safety. When the algorithm estimates the pilot is not suffering from spatial disorientation, the nominal instrument display information (including landing point select, fuel remaining, terrain hazards, etc.) will be provided, avoiding an unnecessary burden upon the pilot. As such, we envision the adaptive display system will serve as a pilot aid, assisting the crewmember as needed. Completing this approval, we have exited the definition phase of our project.

Next, we have coordinated with colleagues at NASA Langley for the detailed implementation of our countermeasure adaptive display. We have a site visit planned for mid-November to coordinate technical details of implementing our system (and other associated experimental needs) into their lunar-landing simulation and display environment. Finally, we have extensively coordinated with colleagues at NAMRU-D regarding plans for the capstone experiments using the DRD. This has included technical discussions of necessary instrumentation (e.g., accelerometers and inertial measurement units) for our planned experiments, as well as administrative coordination (e.g., developing Cooperative Research and Development Agreement / CRADA documentation).

In addition to making progress in preparation for capstone experiments in the DRD, we completed our first set of preliminary experiments in our laboratory. First, we have developed a laboratory based capability for the hyper-Gx paradigm, planned for eventual use in the DRD, in a gravity transition analog. Participants spin on a centrifuge in hyper-Gx (i.e., the net force is “eye balls in”) for an extended period of time. When the centrifuge is spun down, the transition back from hyper-Gx tends to lead to impaired sensorimotor function and motion sickness, serving as an analog for astronaut gravity transitions. In our laboratory, the subject’s head is positioned 9 feet off-axis and spun to produce 2Gx for approximately 1 hour. In our first set of laboratory experiments, following the hyper-Gx exposure, subjects are transitioned to our Tilt Translation Sled (or TTS) and passively experience various tilts (and, in some cases, translation motions) and report their perception of tilt, using a common subjective haptic horizontal task. Beginning with roll tilt, perceptions are compared to those of subjects reporting in a control condition where they lay supine for 1 hour. This controls for the direction of the net gravito-inertial loading, but with only 1Gx, rather than 2Gx on the centrifuge.

While perceptions of roll tilt are qualitatively similar, we found significant underestimation of roll tilt following the hyper-Gx paradigm, in comparison to that following laying Supine. Next, we will expand upon our results for roll tilt perception and study pitch tilt perception, where we anticipate the orientation of the hyper-Gx paradigm may induce a larger effect. We will incorporate the previous and upcoming findings into our computational model for spatial orientation perception and the associated algorithm for identifying spatial disorientation.

In addition, we have made advancements to our human-rated motion device, the Tilt Translation Sled (or TTS), which we plan to use for preliminary investigations prior to the capstone assessments in the DRD. Specifically, we have implemented a manual control piloting mode that is analogous to lunar landing, whereby joystick deflections lead to a roll tilt motion, which is then coupled to a lateral acceleration in the same direction (i.e., tilt to the left leads to acceleration to the left). The subject is tasked with controlling translation motions via this coupled motion, similar to the manual control task during the final stages of lunar landing prior to touchdown. This control mode has been fully implemented and tested with pilot subjects in the loop. Finally, as an initial demonstration we have created a software implementation of our preliminary spatial disorientation algorithm on the TTS device. In real-time, the algorithm processes TTS motions (roll tilt and lateral translation) through our computational model for human spatial orientation perception and then computes a unidimensional metric of how disoriented the pilot is likely to be at that instant in time. The spatial disorientation metric is programmed on the TTS to trigger a change in the instrument display shown on a tablet in front of the participants.

As a major activity, team personnel attended and participated in a multi-day meeting at NASA Langley Research Center. Activities included sharing of technical information and demonstrations of prototype displays, interfaces, and control modes planned for piloted lunar landing as part of the Artemis program. The team presented to NASA colleagues within the Human Research Program, crew training, and flight simulation groups, regarding the proposed approached, planned experiments, and deliverables of this project. Feedback from NASA colleagues was documented and is being integrated into our project plans. Finally, our team has coordinated with colleagues at the NAMRU-D regarding initial plans for the capstone experiments using the DRD. This has included technical discussions of necessary instrumentation (e.g., accelerometers and inertial measurement units) for our planned experiments, as well as administrative coordination (e.g., developing Cooperative Research and Development Agreement / CRADA documentation).

Through coordination with NASA Human Research Program personnel and managers, our team was tasked with modifying our original proposal to more extensively and precisely defining the countermeasure intervention we envisioned implementing and assessing, that would be triggered by our spatial disorientation algorithm. Through considering various alternatives, either that our team has previous experience with, or those which have been proposed by others, we refined the potential alternatives. Our plan, the modification of the original proposal, and its resubmission to the NASA Human Research Program is nearly complete. At this time, we envision the primary approach is for an adaptive display, which enhances the saliency (visual and auditory) of vehicle attitude and motion information in real-time based upon the spatial disorientation algorithm. Specifically, only when the algorithm deems the astronaut pilot is likely to be spatially disoriented does it automatically increase the saliency of critical information on the instrumentation display regarding vehicle attitude (roll and pitch), and motion, to help the pilots reorient themselves in order to improve piloting performance and safety. When the algorithm estimates the pilot is not suffering from spatial disorientation, the nominal instrument display information (including landing point select, fuel remaining, terrain hazards, etc.) will be provided, avoiding an unnecessary burden upon the pilot. As such, we envision the adaptive display system will serve as a pilot aid, assisting the crewmember as needed. In addition, we are considering a few alternative countermeasure interventions and envision initial human-in-the-loop evaluation in our laboratory, prior to final selection for the use in NAMRU’s DRD lunar landing simulator.

In addition to making progress in preparation for capstone experiments in the DRD, we are making technical progress for preliminary experiments in our laboratory. First, we have developed a laboratory based capability for the hyper-Gx paradigm, planned for eventual use in the DRD, in a gravity transition analog. Participants spin on a centrifuge in hyper-Gx (i.e., the net force is “into the chest”) for an extended period of time. When the centrifuge is spun down, the transition back from hyper-Gx tends to lead to misperception of orientation, impaired sensorimotor function, and motion sickness, serving as an analog for astronaut gravity transitions. In our laboratory, the subject is positioned 9 feet off-axis and spun to produce 2Gx for approximately 1 hour. Thus far, we have safety tested and assessed the hyper-Gx analog in a number of participants, demonstrating feasibility.

In addition, we have made advancements to our human-rated motion device (the Tilt-Translation Sled, or TTS) which we plan to use for preliminary investigations prior to the capstone assessments in the DRD. Specifically, we have implemented a manual control piloting mode that is analogous to lunar landing, whereby joystick deflections lead to a roll tilt motion, which is then coupled to a lateral translation in the same direction (i.e., tilt to the left leads to translation to the left). The subject is tasked with controlling translation motions via this coupled motion, similar to the manual control task during the final stages of lunar landing prior to touchdown. This control mode has been fully implemented and tested with pilot subjects in the loop. Finally, as an initial demonstration, we have created a software implementation of our preliminary spatial disorientation algorithm on the TTS device. In real-time, the algorithm processes TTS motions (roll tilt and lateral translation) through our computational model for human spatial orientation perception and then computes a unidimensional metric of how the pilot is likely to be disoriented at that instant in time. The spatial disorientation metric is programmed on the TTS to trigger a change in the instrument display shown on a tablet in front of the participants. Initial pilot tests have shown that when the spatial disorientation metric triggers the instrument display, the pilot is better able to pilot the manual control motions of the TTS. Future work will build upon this to perform a preliminary human subject experiment, leading up to the capstone DRD experiment.