AAUSAT 6: An Experimental Platform in Space
AAUSAT6, is our sixth student-developed satellite from Aalborg University. As with our previous missions, the primary purpose is education, where we want to elevate students and our members to their highest potential.
To achieve this goal, the satellite bus itself is the payload. It contains multiple software-defined elements that can be reconfigured and updated over the air. This includes critical elements and non-critical systems such as the Camera and Software Defined Radio (SDR). These systems will be able to serve the next generation of students and researchers at AAU, enabling in-orbit experimentation.
- 2U CubeSat spanning 20x10x10cm
- A complete redesign with knowledge from former missions
- Video streaming enabled by DVB-S2 & improved pointing accuracy
- Firmware Image Server enabling over-the-air updates
- An In-orbit experimental platform for UHF & S-band radio
A CubeSat designed entirely by students.
Following our objective of education, we have a mantra of doing everything DIY and in-house at our lab. This entails that every system from satellite-bus to payload has our members’ fingerprints all over it. They are engaged from design, construction, testing and operating the satellite once it reaches orbit.
This gives our students a unique opportunity to learn cooperation and advanced system engineering from hands-on experience.
The mission payload
The first satellite from AAU, AAU Cubesat had the objective of taking an image of Aalborg. This required a camera, active attitude control of the satellite and a radio capable of transmitting the image back to a ground station located at AAU.
While the original mission was a success, no satisfactory images were obtained by the satellite due to limited altitude control. AAUSAT6 hopes to redeem this goal and achieve in-orbit imagery both through stills and live video! The satellite includes onboard processing, allowing students to experiment with image processing and machine learning. This coupled with a versatile SDR-subsystem to evaluate new communication protocols, ensuring the satellites brings value throughout its entire mission duration.
Camera in space
For this mission, the IMX477 camera sensor has been chosen, together with optics capturing Aalborg municipality. The sensor supports streaming of 4K@60fps via the MIPI CSI-2 protocol to the Onboard Data Handling system (OBDH), for onboard processing.
However, the communication chain is designed to support a livestream at 1080p@60fps to the ground station localised at AAU in Aalborg, through the use of the DVB-S2 protocol.
The unused resolution leaves room for digital signal processing, which can include algorithms such as digital zoom, narrowing FoV by intelligently tracking features and improving attitude determination.
Onboard Data Handling
Former AAU Satlab missions consisted of hardware and software, made to serve a primary objective throughout their entire lifetime. This has limited the appeal for the next generation of students to continue using the satellites in their later stages of life, when the mission is finished. AAUSAT6 aims to serve new students and researchers until it fails or decays. It is achieved through its software defined subsystems such as the OBDH.
The OBDH is a non-critical subsystem allowing us to lower the entrance level for running experiments onboard. It runs embedded Linux for high-level code execution and has direct access to the camera feed and sensor data from the whole satellite.
It will serve users as a powerhouse of a centralised computing platform, based on the NXP I.MX 8M Plus System-On-Chip (SoC). This computing unit contains onboard graphics and neural processing capabilities, which make it ideal for machine learning and computer vision applications. Examples could be the previously mentioned image processing and advanced fault detection of the satellite.
The Neural Processing Unit (NPU) can run machine learning models up to 2.3 TOPS. The maximum power consumption is limited to 4.5W when the CPU, GPU and NPU all run at full speed [www.compulab.com].
Software defined radio platform
A UHF telemetry & Control link is with the CC1120 transceiver. Besides this stabile connection, two SDR systems enables reconfigurable uplink-downlink capabilities.
To achieve this the hardware combination known from the “adalm-pluto” is used. This allows a wide variety of configurations between the satellite and ground-station to be tested.
The ground station itself consists of UHF equipment used by former AAUSAT missions, however with the addition of the dish antenna used by the first danish satellite [Ørsted], refitted as a S-band receiver with tracking capability.
In orbit experimentation for students
Inspired by initiatives like Astro Pi, a satellite subsystem is dedicated to behave as a sandbox enabling practically anyone to execute their own programs, read sensors & collect data, onboard a “Student Sensor Board”.
The hopes of this is to allow students as early as high school level to get a hands on experience with the STEM, and the danish aerospace sector.
The Satellite bus
what makes this project unique, is the goal of designing every subsystems inhouse, by AAU students! This ambitious goal have fortunately been achieved before by former Asand grants us a huge bank of knowledge to go from.