TigerCub: An Accessible, Open-Source PocketQube Platform

Abstract

The past few decades have seen an explosion of nanosatellite development, with the proposal of the CubeSat in 1999 followed by the PocketQube in 2009. CubeSats have seen wide use across educational, industry, and scientific applications. PocketQubes, a smaller 5-cm cubical form factor, have seen growing popularity in the past few years but still lack significant development and regulation compared to CubeSats. PocketQubes have a significant cost and time-of-development advantage over larger satellites due to their smaller size, and they have been launched by both commercial companies and educational institutions such as Alba Orbital, G.A.U.S.S., and T.U. Delft. One component of PocketQubes poses a significant challenge to first-time developers: the communications module. Many student-developed small satellite missions fail due to the loss of downlinking ability after launch; most radio modules are also difficult to test from the ground. A promising but yet-unproven option for PocketQube developers is the Iridium satellite network, which has been successfully used in CubeSat missions to provide communication from satellites to Iridium’s ground stations. Leveraging the Iridium satellite network will simplify PocketQube development and provide an opportunity for developers to perform conservative downlinking tests and prove link budgets from ground on Earth prior to launch. We propose TigerCub, a modular, mission-agnostic PocketQube platform designed for student development that features SparkFun’s RockBLOCK 9603, an Iridium-based communications module. The TigerCub platform aims to be an open-source, low-cost, accessible option for students. Besides the Iridium communications module, the TigerCub features an Arduino-based flight computer, an electrical power system derived from BHDynamic’s open-source DynOSSAT EDU, a sheet-metal structure, and allocated, interface-controlled space and power for a payload. We conduct testing and analyses to confirm the downlinking abilities of the Iridium module and power positivity for the spacecraft. Finally, we create a user's guide for developers who wish to use TigerCub. As a new PocketQube platform, TigerCub will contribute to the growing number of open-source platforms available and help establish best practices for future PocketQube development.