When Hackaday announced winners of the 2014 Hackaday Prize, a bunch of hackers from Greece picked up the grand prize of $196,418 for their SatNOGS project – a global network of satellite ground stations for amateur Cubesats.
The design demonstrated an affordable ground station which can be built at low-cost and linked into a public network to leverage the benefits of satellites, even amateur ones. The social implications of this project were far-reaching. Beyond the SatNOGS network itself, this initiative was a template for building other connected device networks that make shared (and open) data a benefit for all. To further the cause, the SatNOGS team set up the Libre Space Foundation, a not-for-profit foundation with a mission to promote, advance and develop Libre (free and open source) technologies and knowledge for space.
Now, the foundation, in collaboration with the University of Patras, is ready to launch UPSat – a 2U, Open Source Greek Cubesat format satellite as part of the QB50 international thermosphere research mission. The design aims to be maximally DIY, designing most subsystems from scratch. While expensive for the first prototype, they hope that documenting the open source hardware and software will help kickstart an ecosystem for space engineering and technologies. As of now, the satellite is fully built and undergoing testing and integration. In the middle of July, it will be delivered to Nanoracks to be carried on a SpaceX Dragon capsule and then launched from the International Space Station.
A typical Cubesat like this one consists of several sub-systems. The main one being the structural unit that holds it all together. The Electrical Power Subsystem (EPS) module produces, stores, distributes and controls the Cubesat’s electrical power. The Science Unit (SU) is the main payload, consisting of a multi-needle Langmuir Probe instrument which works by measuring the current collected individually from four needle probes, placed in front of the satellite.
The secondary payload is the Image Acquisition Component (IAC) that does terrestrial imagery using a DART4460 Linux embedded board running a custom build of OpenWRT, a Ximea MU9PM-MH USB Camera and a 50mm lens attached to the camera, providing resolution between 11 m to 18 m per pixel depending on the Satellite’s altitude. The Attitude Determination and Control Subsystem (ADCS) stabilizes the satellite and orients it in desired directions during the mission.
The On Board Computer subsystem (OBC) is the brains of the satellite. It facilitates all core flight functionality and implements all major decision-making and monitoring of all subsystems. At its heart is a STM32F4 microcontroller running a customised version of FreeRTOS. Ground communication is implemented using ECSS-CCSDS telemetry and telecommand packet standard as defined by ECSS-E-70. The on-board Communications Subsystem (COMM) is based on the CC1120 RF Transceiver chip, a device that has been employed successfully in previous missions.
All of the extensive project documentation is available on their GitHub Repository, and blog posts on their website record the major milestones along their journey, so do check it all out. And then keep a lookout for announcement of the launch and deployment of the UPsat sometime in July. In the meanwhile, check out this post announcing the winners of the 2014 Hackaday Prize. May the Force be with you, UPsat.