This Handbook, produced by the Marshall Space Flight Center (MSFC) Engineering Directorate, documents a broad range of critical engineering principles needed for communication between stakeholders and the engineering community. The principles and guidance contained in this Handbook help define MSFC design practices that have become a part of our engineering excellence. These principles are required to ensure proper technical integration across the entirety of the engineering disciplines at MSFC and products that can be physically integrated during production. The Handbook is a product of the combined MSFC engineering discipline community, including the Propulsion Systems Department, the Spacecraft & Vehicle Systems Department, the Space Systems Department, the Test Laboratory, the Mission Operations Laboratory, the Materials & Processes Laboratory, the MSFC Chief Engineer's Office, and the Safety and Mission Assurance organization.