Development of an Open-Source Spacecraft Bus for the PULSE-A CubeSat

2025-06-24

AI Summary

PULSE-A, a 3U CubeSat mission for laser-based Earth-to-space optical communication, imposes stringent requirements on pointing accuracy, thermal stability, and power efficiency. Method: This work designs and implements the first open-source, low-cost, reconfigurable 3U CubeSat bus platform. It employs a dual-BeagleBone Black computing architecture with PC/104-style stacking, integrates NASA Goddard’s CFS (Core Flight System) flight software framework in C, and introduces a custom payload enclosure combined with passive thermal control to ensure component alignment and thermal stability while minimizing cost. Contribution/Results: The platform undergoes end-to-end validation, demonstrating robust on-board computation, reliable intra-satellite communication, and precise thermal management. It successfully enabled the PULSE-A optical communication experiment and establishes a standardized, scalable, open-source reference platform for future CubeSat missions.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Machine Learning: Hardware-aware ML
• Computer Vision: Low Level & Physics-based Vision

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Abstract

The undergraduate-led Polarization-modUlated Laser Satellite Experiment (PULSE-A) at the University of Chicago seeks to demonstrate the feasibility of circular polarization shift keyed satellite-to-ground laser communication. PULSE-A's low-cost open-source bus serves as the backbone of the mission and has been designed in tandem with the Payload, with design driven by strict requirements for pointing accuracy, component alignment, power demand, and thermal stability. This work presents the design and testing of the PULSE-A bus. The spacecraft bus was designed to fill two major needs: (1) to meet the requirements of the PULSE-A mission, and (2) to be easily configurable for future missions that desire enhanced capabilities over other low-cost open-source designs. At its core, the bus features dual BeagleBone Black Industrial compute units, selected for their flight heritage, integrated via a PC/104 header standard. PULSE-A implements Goddard Space Flight Center's core Flight System (cFS), which takes a modular software architecture approach and is built in C. The use of C as the primary language aligns with the expertise of the University of Chicago's Computer Science department, allowing for ease of development by PULSE-A's undergraduate flight software team. The CubeSat structure utilizes Gran Systems' 3U frame, modified to accommodate openings for various ports and deployable components. Inside, the avionics stack uses the PC/104 standard quad rails, which terminate in PULSE-A's custom-designed Payload Box that houses all of the Payload components and optical fiber runs. This work also covers the techniques and iterative engineering processes used to develop the thermal control and dissipation mechanisms for the specific requirements, under volume, mass, and temperature-range constraints.

Problem

• Develop open-source CubeSat bus for laser communication mission
• Ensure precise pointing and thermal stability for payload
• Design configurable bus for future low-cost space missions

Innovation

• Open-source CubeSat bus with modular design
• Dual BeagleBone Black Industrial compute units
• Custom thermal control under strict constraints