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The scientific mission objectives of the Stuttgart Operated University Research CubeSat for Evaluation and Education are meteor observation, measurement of the lower Earth's atmosphere during re-entry as well as technology demonstrations. The meteor observation is done by pointing a camera towards Earth and continuously taking images during Eclipse. Since it is not possible to downlink all images, an on-board detection algorithm is necessary and mission critical. Therefore, this algorithm needs to be tested thoroughly. Realistic test data showing meteors from orbit is needed to properly develop and test the algorithm. Existing videos, provided by the Planetary Exploration Research Center, captured from the ISS are used as a baseline but are not sufficient to test the algorithm. The videos do not have the diversity of meteors needed and the meteor properties are not settable which makes it difficult to test the detection algorithm in as many scenarios as possible. Therefore, an artificial meteor program was developed to simulate meteors with given properties as perceived from a meteor observation system in a low Earth orbit. Here, we present the details of the artificial meteor program, its working principle and how we tested an algorithm for meteor detection. The user can choose between different background videos, the existing ISS videos from PERC or the self-generated videos. Each different background is used to test a different aspect of the meteor detection algorithm. The ISS videos from PERC provide more diverse backgrounds than the self-generated videos with e.g., clouds and lightning. For these self-generated videos, a program is developed to take image sections of NASA’s Black Marble and putting them frame by frame together into a video. These videos are more suitable for simulating satellite rotation and camera properties. Independent of the background video, settable meteor properties contain important characteristics of a meteor like the light curve, brightness, speed, direction and shape. Additionally, the user can choose the meteor position in the video frame, in which frame it appears and which distance it covers. Furthermore, distortion settings can be applied which contain airplanes with adjustable parameters and scalable noise. Only a properly working meteor detection algorithm leads to a success of a mission critical part of the SOURCE CubeSat. Therefore, the development of this artificial meteor generation program is crucial. Furthermore, this technology demonstration of developing and especially testing a meteor detection algorithm will enable future space-based missions for meteor observations

The Educational Irish Research Satellite (EIRSAT-1) is a 2U CubeSat being designed, built and tested at University College Dublin. A FlatSat platform known as EIRFLAT-1 has been constructed to enable the testing and development of the CubeSat. EIRFLAT-1 facilitates the electrical connections between CubeSat components while leaving key interfaces accessible for test equipment and allowing for the hot swapping of components. Commercial Off The Shelf and in-house developed hardware has been tested using EIRFLAT-1 at component, subsystem and full system level. In addition, the FlatSat has been used for flight software development. This paper describes the design of EIRFLAT-1 including electrical and mechanical components and additional ground support equipment developed to assist in the testing and development activities. EIRFLAT-1 has proven to be an invaluable tool for testing and has led to the discovery of issues and unexpected behaviour with flight hardware which would have contributed to schedule delays if undiscovered until after the satellite was assembled. Moreover, EIRFLAT-1 facilitated early and incremental testing of both software and operations procedures. The schematics for the electrical design of EIRFLAT-1, which is compatible with all CubeSat Kit PC/104 components, has been made publicly available for use by other educational CubeSat teams

Student Satellite program at TalTech, Tallinn University of Technology, Tallinn, Estonia was initiated in 2014 with an aim to impart space technology knowledge to the Estonian students as well as assist towards development of new Space Technologies in Estonia. Two 1-Unit CubeSat named Koit and Hämarik that translates respectively as Dawn and Twilight in Estonian are part of the TalTech Satellite Program. The main scientific mission of the CubeSats was to demonstrate Earth observation and Optical Communication technology. Satellites had two types of cameras, an RGB Camera and an NIR Camera to carry out Earth Observation over Estonia. Testing High Speed Optical communication technology from LEO (Low Earth Orbit) was the second major scientific goal and for this purpose the CubeSats had LED (Light Emitting Diode). Koit CubeSat was successfully launched to space on-board Soyuz rocket on July 5, 2019 and Hämarik CubeSat was launched to Space on September 3, 2020 on-board Arianespace Vega Rocket. Koit CubeSat did not contact the Ground station for more than a year since its launch and it was assumed to be lost but on November 21, 2020 it made the first contact with the Ground Station. Hämarik CubeSat was first contacted on November 15, 2020. The team has been successful in updating software of Hämarik and further work is being done on the software with broader functions. Optical communication has not been tested yet because ground station for optical communication has not been developed yet but a good achievement in the path to optical communication was to see the satellites with small hobby telescope and one of the satellite team member was successful to detect the Hämarik CubeSat on 17 August 2021 which was at a distance of about 792 Kilometres. Satellite team is in contact with the Hämarik and has been successful to download a few thumbnails and is working to establish a quick data connection with it and determine its exact position so that the cameras can be focused towards the Earth in order to get the whole images captured by the CubeSat.

Faculty members, undergraduate and graduate students of the School of Communication and Aerospace Engineering (Polytechnical University of Catalonia) are participating in a series of studies to determine the thermospheric density. These studies involve planning a space mission, designing and constructing small satellites, and performing related data analysis. This article presents a method for determining the thermospheric density and summarises the academic context in which we develop our work. Several studies have reported the existence of a downtrend in thermospheric density, with relative values ranging from –2% to –7% per decade. Although it is well known that solar and geomagnetic activity are the main drivers of the variations of the thermospheric density, this downtrend was reported to be caused by the rise of greenhouse gases. We present an update of this progression, considering the last solar cycle (2009-2021) and using Two-Line Elements sets (TLE) of 1U CubeSats and the spherical satellites ANDE-2. TLEs were used to propagate the orbits numerically using SGP4 (Simplified General Perturbations), and then compute the average density between two consecutive TLEs by integrating the appropriate differential equation. Then, using the NRLMSISE-00 (Picone 2002) and JB2008 (Bowman 2008) atmospheric models, we calculated an average density deviation per year. We built a comprehensive time series of the thermospheric density values, ranging from 1967 to the present. We merged Emmert (2015) thermospheric density data and our results computed both with NRLMSISE-00 and with JB2008. A linear regression on the combined dataset yields a decreasing trend of –5.1% per decade. We also studied the geomagnetic and solar activity to isolate the possible greenhouse gasses effect during the considered period. Our results show a strong correlation between geomagnetic activity and density deviation near the solar minima, and we propose that the cause of the previously reported long-term density deviation could be a poor adjustment of the effects of geomagnetic activity. Finally, we proved that orbital information from small satellites could be efficiently used to assess the evolution of thermospheric density variations. Additional data obtained from future missions (as the one proposed by our group) will eventually allow a better characterisation of the atmospheric density and help disentangle the possible greenhouse gasses effects on its variations

The Earth Observation Satellite System Design training course was first offered in 2018 at ESA Academy’s Training and Learning Facility at ESA’s ESEC Galaxia site in Belgium, and again in 2021 in an online format under the Covid-19 pandemic situation. The course covers the end-to-end design and development process of satellite Earth observation systems. Two major challenges were faced by the teaching experts, consisting of the active and retired ESA staff, as well as ESA Academy’s instructional designers for its development: (1) Condensing such a vast subject domain, associated with a complex, multi-disciplinary engineering undertaking, into a compact format (e.g. 4.5 days in 2018) without sacrificing the quality of the essential technical knowledge, engineering practices and logic as taught; (2) Presenting the course materials in a comprehensive form to a group of 30 M.S. and Ph.D. students with their backgrounds generally not covering all of the technical disciplines associated with the course subject domain. The 2021 online edition of the training course, which drew on lessons learnt from 2018, consisted of 18 lectures, plus 5 group project sessions where the students put their acquired knowledge into practice and learned to work in a project team environment. This paper concentrates on the approach and logic adopted by the instructional team to address the above 2 challenges. Difficulties encountered in some of the areas, e.g. remote sensing instrumentation designs, are discussed

Thermal knife HDRMs (Hold Down and Release Mechanisms) are commonly used in CubeSats and other small satellites. However, detailed information on proven designs is difficult to find. Design of a robust and reliable mechanism can present technical challenges which may only become apparent during testing, and often only when tested in a space representative environment. A custom thermal knife HDRM was designed and built for the antenna deployment module of EIRSAT-1 to deploy four coil spring antenna elements, but the same or a similar design could be repurposed quite easily to release a wide range of CubeSat deployables. In this design resistors are used to cut dyneema lines. For robustness and reliability, the thermal response of the mechanism must be well understood. To reach the melting point of the dyneema (150C) the power dissipated in the resistors must often exceed the maximum rated value. Therefore, choosing the operating current and the burn time is a careful trade-off between ensuring that the resistor reliably cuts the dyneema line and ensuring that the resistor, solder joints, PCB and nearby components are not damaged by the high temperatures. These choices are further complicated by the requirement that the mechanism operates over a range of temperatures. A thermal vacuum test campaign was carried out to better understand and characterise the thermal behaviour of the EIRSAT-1 mechanism. For the test a model of the mechanism was built with several temperature sensors installed. Two of these sensors were installed directly on the body of the resistors using a thermally conductive epoxy. Burn tests were performed in vacuum at temperatures between -37C and +56C. The test shows many interesting results including the effect of the dyneema lines on the thermal response, the possibility of desoldering the burn resistors and a comparison between the performance at ambient and vacuum conditions. Finally, a summary is given of the key technical challenges associated with this type of mechanism along with some recommendations to help make future designs more robust and reliable.

The Remote sensing and Interference detector with radiomeTry and vegetation Analysis (RITA) is one of the Remote Sensing payloads selected as winners of the 2nd GRSS Student Grand Challenge in 2019, to fly on board of the 3U AlainSat-1. This CubeSat is being developed by the National Space Science and Technology Center (NSSTC), United Arab Emirates University. RITA has been designed as an academic mission, which brings together students from different backgrounds in a joint effort to apply very distinct sensors in an Earth Observation mission, fusing their results to obtain higher-accuracy measurements. The main payload used in RITA is a Total Power Radiometer such as the one on board the FSSCat mission. With these radiometric measurements, soil moisture and ice thickness will be obtained. To better characterize the extensive Radio-Frequency Interferences received by EO satellites in protected bands, several RFI Detection and Classification algorithms will be included to generate a worldwide map of RFI. As a novel addition to the 3Cat family of satellites and payloads, a hyper-spectral camera with 25 bands ranging from 600 to 975 nm will be used to obtain several indexes related to vegetation. By linking these measurements with the soil moisture obtained from the MWR, pixel downscaling can be attempted. Finally, a custom- developed LoRa transceiver will be included to provide a multi-level approach to in-situ sensors: On-demand executions of the other payloads will be able to be triggered from ground sensors if necessary, as well as simple reception of other measurements that will complement the ones obtained on the satellite. The antennas for both the MWR and the LoRa experiments have been developed in-house, and will span the entirety of one of the 3U sides of the satellite. In this work, the latest development advances will be presented, together with an updated system overview and information about the operations that will be conducted. Results obtained from the test campaign are also presented in the conference.