New in the NSS Space Settlement Journal is the article Gravitat: Proposal for a Standard Design Vessel for Space Settlement, by Dr. Pietro Calogero.
In this paper I propose a “gravitat” as a two-pod vessel rotating around a central truss. I argue that a standard vessel design can serve multiple roles for extended crewed missions: as a vehicle, as an orbiting station, and as a surface base mounted on low-gravity planetary bodies. These roles share substantially overlapping design constraints: low total mass for both delta-V and station-keeping; spin-gravity for crew health and simplification of system design; and a nearly-closed environmental life-support system with significant fault-tolerance. Furthermore, a common design enables the most rapid accumulation of field-test time to identify strengths, weaknesses, and overall risk management of a complex vessel.
The proposed design includes two pods enclosed in three concentric fabric envelopes, tethered to a central truss by cables arranged to minimize oscillation. The pods consist of internal trusses, parallel to the axis of rotation, that support their dwelling decks and multiple garden shelves. The structural design is deliberately simple, to maximize reliability and durability. Complexity emerges in the details of long-term life-support, which requires years of empirical testing and observation to enable actual settlement of space.