This project develops a standardized, modular satellite bus designed to simplify the integration of 450 kg-class payloads for commercial rideshare missions. Unlike traditional mission-specific spacecraft structures, the proposed bus provides a reusable platform with a configurable interior mounting interface, reducing development time, engineering effort, and integration costs for future missions. The design incorporates a lightweight conical isogrid structure optimized for launch loads, passive thermal management, and compatibility with the Rocket Lab Advanced Lightband (ALB) separation system and SpaceX Falcon 9 rideshare requirements. Structural, thermal, and modal analyses, along with prototype fabrication, are used to validate the design's performance, manufacturability, and commercial feasibility.