Cubesat Fastener Selection: Critical Considerations for a Successful Mission

Fasteners may seem like a small detail in the grand scheme of cubesat design, but their selection is crucial for mission success. Cubesats are subjected to a variety of harsh conditions throughout their lifecycle, from the intense vibrations of launch to the extreme temperatures and vacuum of space.

Here's a quick rundown of factors to consider when choosing the right fasteners:

• Material Compatibility: The materials used for fasteners must be compatible with the cubesat structure and other components to prevent galvanic corrosion and ensure structural integrity. Aluminum 6061-T6 is often used for the main structure.

• Strength and Durability:  Fasteners must withstand the loads experienced during launch, deployment, and on-orbit operations. The selected fasteners should have a sufficient factor of safety to account for unforeseen circumstances. The Artemis CubeSat Kit, for example, has a factor of safety of 4.98 for its fasteners under launch acceleration load.

• Locking Mechanisms: To prevent loosening due to vibration, fasteners should incorporate locking features such as prevailing torque nuts, lock wire, or threadlocker. These features ensure that fasteners remain securely in place despite the dynamic environment of spaceflight.

• Size and Weight: Every gram counts in a cubesat, so fastener size and weight must be minimized without compromising strength.

• Corrosion Resistance:  Space is a harsh environment, and fasteners must be resistant to corrosion to maintain their functionality throughout the mission. Hard anodizing is often used on aluminum surfaces to prevent cold welding.

• Rework Considerations: Fasteners might need to be removed and reinstalled during assembly, testing, and integration. Fastener selection should consider the ease of rework and the potential for damage during these processes.

• Compliance with Standards: Fasteners must meet the specific requirements outlined in the CubeSat Design Specification (CDS) and the interface control document (ICD) for the chosen dispenser and launch vehicle.

  
  

Thorough consideration of these factors will ensure a robust and reliable cubesat structure, paving the way for a successful mission!