The ESA Parastronaut Feasibility Project: Investigating the Need and Contents of Physical Performance Tests for an Inclusive European Astronaut Corps.

INTRODUCTION: In 2022, the European Space Agency (ESA) held the first astronaut selection since the beginning of space flight that allowed physically impaired astronaut candidates to be selected in an inclusive European astronaut corp. The main objective of the 'parastronaut feasibility project' is to investigate if physical performance tests (PPTs) should be part of future astronaut recruitments for an inclusive ESA astronaut corps to test their flight readiness. The objectives of this study are (1) to assess if future (para-)astronaut recruitment campaigns should include PPTs to ensure flight readiness, safety, and mission success; (2) if so, which areas of physical performance should be tested to mimic nominal and off-nominal crew activities during all phases of a space mission; and (3) to assess whether PPTs are compatible with the ethical principles of equal opportunity for an inclusive pool of astronaut candidates. METHODS: 58 subject matter experts with specialisations in space physiology, operational human space flight, space medicine, medical ethics or parasports were interviewed in two rounds using the Delphi method. Both qualitative and quantitative data were obtained, analysed, categorised, and visualised using the qualitative research tool NVivo and Excel. RESULTS: Two thirds of the experts were in favour of adding PPTs to future astronaut selections and recommended to implement them for both physically unimpaired and physically impaired astronaut candidates. The main physical skills that should be examined are space-related, mission-specific coordination skills of the upper extremities, followed by endurance performance and stamina, dexterity of the upper extremities, motor learning ability and mobility. CONCLUSION: Based on this study, it is clear that PPTs should be part of future astronaut selection campaigns. However, the content of these PPTs must be carefully evaluated and validated using existing data on crew activities before, during, and after space flight, while considering equal opportunities in the context of human space flight. Historical considerations have influenced current astronaut requirements, but this study's findings indicate a need to reassess these requirements for future inclusive selection campaigns, as their validity and necessity remain uncertain.

Unimodal and crossmodal working memory representations of visual and kinesthetic movement trajectories.

The present study investigated whether visual and kinesthetic stimuli are stored as multisensory or modality-specific representations in unimodal and crossmodal working memory tasks. To this end, angle-shaped movement trajectories were presented to 16 subjects in delayed matching-to-sample tasks either visually or kinesthetically during encoding and recognition. During the retention interval, a secondary visual or kinesthetic interference task was inserted either immediately or with a delay after encoding. The modality of the interference task interacted significantly with the encoding modality. After visual encoding, memory was more impaired by a visual than by a kinesthetic secondary task, while after kinesthetic encoding the pattern was reversed. The time when the secondary task had to be performed interacted with the encoding modality as well. For visual encoding, memory was more impaired, when the secondary task had to be performed at the beginning of the retention interval. In contrast, memory after kinesthetic encoding was more affected, when the secondary task was introduced later in the retention interval. The findings suggest that working memory traces are maintained in a modality-specific format characterized by distinct consolidation processes that take longer after kinesthetic than after visual encoding.

Working memory maintenance contributes to long-term memory formation: evidence from slow event-related brain potentials.

Behavioral research has led to conflicting views regarding the relationship between working memory (WM) maintenance and long-term memory (LTM) formation. We used slow event-related brain potentials to investigate the degree to which neural activity during WM maintenance is associated with successful LTM formation. Participants performed a WM task with objects and letter strings, followed by a surprise LTM test. Slow potentials were found to be more negative over the parietal and occipital cortex for objects and over the left frontal cortex for letter strings during WM maintenance. Within each category, they were enhanced for items that were subsequently successfully remembered. These effects were topographically distinct, with maximum effects at those electrodes that showed the maximum negativity during WM maintenance in general. Together, these results are strongly consistent with the ideas that WM maintenance contributes to LTM formation and that this may occur through strengthening of stimulus-specific cortical memory traces.