Barrelhand is a San Francisco design and engineering studio building mechanical hardware for spaceflight, founded by Karel Bachand. Its work centres on tools intended to stay serviceable and legible over very long timescales — the Monolith EVA/IVA toolwatch, the NanoFiche Memory Disc archive module, and Project One. Development leans heavily on aerospace materials and additive manufacturing, with parts made in collaboration with specialist suppliers rather than in-house.