We propose to design and demonstrate a portable source of lattice-trapped, ultracold strontium (PLUS). The device uses simplified and robust techniques for loading the traps, and directly leverages hardware already developed by AOSense. The simplified architecture for PLUS makes it amenable to future space qualification. When paired with a sufficiently stable local oscillator, PLUS can be operated as an optical lattice clock. Alternatively, the lattice-trapped atoms could serve as a starting point for producing quantum degenerate Sr gases for use in future sensor technologies or fundamental science studies. In the latter case, possibilities span explorations of artificial gauge fields to quantum information processing. In Phase I, AOSense will optimize the expected device performance through extensive modeling, trade-space analysis, and technology validation of the highest risk hardware. The design will cover the physics package and control system at the level of CAD models, ready for procurement that will begin during Phase II. We will also model device applications and generate a parts list and cost estimate for the construction of a prototype during Phase II.