Astrophysics and particle physics rely on large-scale infrastructures, including telescopes, detectors, and accelerators, that are central to scientific inquiry yet often remain inaccessible to the public. These instruments pose specific challenges for engagement: how can they enable encounters with science as an ongoing process rather than a finished product? Recent initiatives have begun to explore how laboratory-based research can be made visible beyond static display. However, meaningful engagement with such infrastructure requires more than proximity or authenticity;it depends on mediation, narrative framing, and situated interaction. This paper reflects on the development of ELISA, a functioning proton accelerator integrated into the exhibitions at CERN's Science Gateway. Rather than offering a replicable model, the installation is presented as a negotiated arrangement shaped by technical constraints, safety considerations, and the need for meaningful public engagement. Its hybrid use as a demonstrator, exhibit, and occasional research tool offers a space where scientific practice becomes visible and open to interpretation. Through live demonstrations and guided facilitation, the project invites visitors to witness scientific work in action. Drawing on science communication and STS perspectives, this case contributes to broader reflections on how research infrastructures can be mobilised as sites of learning, encounter, and epistemic negotiation.
Annabella Zamora (Tue,) studied this question.