Picosatellite Design Incorporates Thin Aluminum Structure and Self-Clinching Fasteners

A reduced parts count and lower weight are attributable to less fastening-related hardware.

The CubeSat standard (10 × 10 × 10 cm and weighing 1kg) has evolved into one of the most widely accepted families of picosatellite designs. A CubeSat can package a universe of payload possibilities for launch into space at a fraction of the cost of traditional multimillion- dollar satellites. The success of any CubeSat project will owe much to how closely participants adhere to unforgiving timelines linked to launches scheduled far in advance. Serving to jumpstart projects and keep them on track within the typical 24 months from inception to launch, Pumpkin, Inc. created an off-the-shelf CubeSat Kit™ offering all the advantages of a standardized assembly. Conforming fully to the recognized CubeSat specification, the kit’s structure, electronics, and software are intended to save time and money.

The kit’s finished, ready-for-launch flight-module structure forms a unique sheet-metal solution, which is predesigned, pre-fabricated, and in stark contrast to how structures usually are produced. Historically, CubeSats have been machined from aluminum blocks carrying the worries over machining error and lost time and resources. Machined blocks further require thick cross-sections to accommodate threaded bosses for fasteners, which limits internal volume and adds bulk in a chassis where every millimeter and every gram will count. Precision sheet-metal construction instead of machining mitigates these issues and facilitates the thinnest possible chassis walls (0.0560" in thickness) without infringing on the overall dimensional tolerances (100 ±0.1mm on a side) demanded in the CubeSat specifications.

Envisioning a very thin 5052-H32 aluminum chassis, designers at Pumpkin turned to threaded fastening hardware for attachment functions. (Much thicker sheet metal can be tapped for threads, but, in this case, the necessarily thicker walls would constrain internal dimensions.) The need for reliable metal threads was fulfilled by installing selfclinching fasteners permanently in the sheet-metal assembly.