OreSat: A Student Team-Based Approach to an Inexpensive, Open, and Modular (1-3U) CubeSat Bus

Most educational CubeSat projects have the same dilemma: not enough money to buy capable COTS hardware, and not enough internal experience (even with teams of students) to build reliable, and inexpensive systems in-house. We present a middle road to the “COTS vs DIY” conundrum: the OreSat bus. OreSat is a fully open source 1U – 3U CubeSat system meant to be built, modified, and flown by student teams. It’s specifically designed to be put together by resource-constrained student teams with “gaps” in their interdisciplinary breadth, as most teams have. OreSat has everything you would expect from a CubeSat system: a 1 – 3U structure, multi-band deployable antenna, solar array, battery pack, on-board computer, radio system, star tracker, reaction wheels, magnetorquers, and SDR GPS receiver. OreSat is built around a high density card-cage system with roughly a 40% higher packing density than the commonly used PC/104-plus stack. Each system is a “card” based on inexpensive 2 and 4 layer PCBs that interface to a common backplane that is capable of carrying CAN, Ethernet, RF, and power. As each CubeSat is unique, the backplane is made bespoke for each mission with 30% of backplane connections available for customization. Student teams can take the existing OreSat systems and build them as is, or modify them for their missions. The OreSat bus is scheduled for first flight in late 2021 (OreSat0, a 1U technology demonstrator), and will be fully deployed in late 2022 as the 2U “OreSat” mission, accepted into the 2017 NASA CubeSat Launch Initiative (CSLI).