SPACE MATERIALS & PROCESS ENGINEERING - SELECTION - VALIDATION - APPLICATION

Selection of materials and processes, along with validation based on the application, are the foundation of structural integrity and mission success for spacecraft. The selected materials and processes are considered Single Point Failure Items because any glitch in them could jeopardize the mission success of multimillion-dollar spacecraft.

Spacecrafts are launched into Geostationary Earth, Medium Earth, and Low Earth Orbits depending on the application. 9,700-pound Global Positioning System GPSIII SV01 spacecraft of the Space Force was launched into MEO, 11,000-pound Geostationary Operational Environmental Satellite (GOES-R) of NASA was launched into GEO, and 24,500-pound Hubble Space Telescope of NASA was launched into LEO. The selected materials must be compatible with LEO, MEO, or GEO, depending on which orbit the spacecraft will operate in during its planned lifetime (~ 15 years). For example, the presence of ultraviolet radiation in LEO converts 96% of Oxygen to Atomic Oxygen. Atomic Oxygen is very reactive and energetic enough to break chemical bonds on the surface of many materials, reacting with them to form oxides.

A typical spacecraft comprises many systems such as, Structure and Mechanisms, Propulsion, Thermal, Electrical & Electronics, Power, Attitude Control, Payload, Communication/Command/Data Handling, etc. Each system requires precise selection of materials and processes to fabricate parts, components, sub-assemblies, and assemblies. The selection is based on the application and functionality of the system, space environment including temperature extremes and radiation effects, compatibility of materials, lifespan of the spacecraft, etc.

Adequate knowledge and experience in Material Science & Engineering, Metallurgical Engineering, Process Engineering, Corrosion Science including Galvanic and Stress Corrosion, Fracture Mechanics, and Failure Investigation & Analysis are necessary for the selection of materials (metals and non-metals) and processes.

A detailed study of the aforementioned aspects will be discussed in the presentation for fabricating exemplary spacecraft considering selection of flawless materials and processes.