Texting Through the Silence: (matrix-conf-2025)

Twenty seconds is a long time when someone can’t breathe. At ESA´s LUNA Analog Facility we turned that reality into a design constraint: a moonwalk emergency with voice cut by design, Matrix/Element carrying clinical guidance across a built-in one-way delay. We tested two styles of instant messaging, open free-text versus a tiny, structured grammar, to coordinate assessment, treatment, and evacuation over a delay-tolerant (store-and-forward) network. The first signals are clear: structure lowers cognitive load and keeps decisions moving even when replies arrive “late.” We’ll share what worked, what didn’t, and how the same patterns translate to Earth during hospital IT outages. With publications in progress, this talk focuses on early signals and the method itself, showing how Matrix enabled care under delay and how small changes could improve resilience. We start with a quick introduction of the LUNA Analog Facility, why a Moon-like regolith hall, ground segment, and “moonwalk” simulation are ideal for testing communications under stress, then walk through our method: we intentionally disabled voice, enforced ~20-second one-way delay, and coordinated clinical care entirely over Matrix/Element on a delay-tolerant (store-and-forward) link. You’ll see how we compared open free-text with a compact, structured chat grammar and which small conventions, clear end-markers, role tags, micro-acks, bounded message size, simple priority cues, reliably reduced ping-pong and cognitive load while keeping treatment safe. From there, we look beyond the Moon: practical takeaways for Earth hospitals facing outages (offline-first clients, lightweight message grammar for critical steps, prebuilt templates), and EVA-oriented tweaks that seem promising, such as lightweight clinical field sets and mobile/edge Matrix homeservers with opportunistic federation under delay. Publications are in progress; this session focuses on the method and early signals and what they imply for building resilient, message-driven care when “real-time” isn’t guaranteed. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://cfp.2025.matrix.org/matrix-conf-2025/talk/PUUXDL/