Post by Dr. Joannes Paulus T. Hernandez, DComm, MAN, RN, CHSE

Have been working on this paper since 2024. Just completed this timely for the 2026 Asian Microgravity Symposium in Japan. "A Multiscale Digital Twin for Modeling Human Sexual Health and Physiology in Outer Space" Dr. Joannes Paulus Tolentino Hernandez Background: As spaceflight expands to commercial operations and long-duration settlements, sexual health and intimacy remain understudied despite their importance for psychosocial well-being (Santaguida & Dubé, 2023). Objective: To develop a multiscale computational digital twin simulating biomechanical, physiological, and behavioral aspects of sexual activity under microgravity, normal gravity, and hypergravity. Methods: A modular digital twin integrated gravity-sensitive movement models, a dual-segment intercourse dynamics model, a penile blood-flow module, and video-derived motion analysis. Simulations were performed at 0.1 g, 1.0 g, and 2.0 g. Results: Gravity strongly affected movement dynamics. Microgravity caused prolonged angular displacement, while hypergravity increased peak velocities. Penile blood-flow remained constant at ~1.50 × 10⁻⁶ m³/s. Multi-metric analysis showed stable center-of-mass with intermittent stress spikes. Conclusions: This early framework suggests microgravity may impair mechanical efficiency of sexual activity, with implications for restraint design, habitat ergonomics, and astronaut well-being. It provides a foundation for future aerospace sexual health research and countermeasures. Keywords: microgravity; sexual health in space; digital twin; biomechanics; aerospace physiology