The power distribution systems of the future will require Solid-State Power Controllers (SSPCs) instead of the less reliable electro-mechanical circuit breakers. The power distribution systems of tomorrow will rely on computer intervention to off-load crews, improve fault handling, and improve system reliability, while protecting the wire and load. The growing diversity of applications and system architectures requires component SSPC manufacturers to offer many advanced features to meet the system designers demands. This paper will focus on the key SSPC features that are being demanded today. To be highlighted are: true I2T protection, Status reporting, BIT, controlled turn-on/off time, leakage current clamp protection, instant trip vs.current limiting, just to mention a few key items. This paper will review the advantages and trade-offs as to their impact on weight, size, safety, and the relative cost. Included as reference is the philosophy of design DDC has taken in its 28Vdc series, 270Vdc series and 28Vdc 80 ampere series of standard products.This paper will also highlight: the overall electrical and mechanical specifications that should be considered; a review of the technologies selected and how they help to keep pace with future applications; the impact of military screening on SSPC reliability through MIL-HDK-217 calculations will be touched upon; and the increase in High-REL Space and military applications will be reviewed from the design and military processing aspect for thick-film hybrid designs.