Cosmo ArduSiPM: An All-in-One Scintillation-Based Particle Detector for Earth and Space Application.

Thanks to advancements in silicon photomultiplier sensors (SiPMs) and system-on-chip (SoC) technology, our INFN Roma1 group developed ArduSiPM in 2012, the first all-in-one scintillator particle detector in the literature. It used a custom Arduino Due shield to process fast signals, utilizing the Microchip Sam3X8E SoC's internal peripherals to control and acquire SiPM signals. The availability of radiation-tolerant SoCs, combined with the goal of reducing system space and weight, led to the development of an innovative second-generation board, a better-performing device called Cosmo ArduSiPM, suitable for space missions. The architecture of the new detector is based on the Microchip SAMV71 300 MHz, 32-bit ARM® Cortex®-M7 (Microchip Technology Inc., Chandler, AZ, USA). While the analog front-end is essentially identical to the ArduSiPM, it utilizes components with the smallest possible package. The board fits in a CubeSat module. Thanks to the compact design, the board has two independent channels, with a total weight of only 40 grams within a CubeSat form factor. The ArduSiPM architecture is based on a single microcontroller and fast discrete analog electronics. It benefits from the continued development of SoCs related to the IoT (Internet of Things) market. Compared with a system with a custom ASIC, this architecture based on software and SoC capabilities offers considerable advantages in terms of cost and development time. The ability to incorporate new commercial SoCs, continuously emerging from advancements in the aerospace and automotive industries, provides the system with a robust foundation for sustained growth over the years. A detailed characterization of the hardware and the system's response to different photon fluxes is presented in this article. Additionally, coupling the device with a scintillator was tested at the end of this article as a preliminary trial for future measurements, showing potential for further enhancement of the detector's capabilities.

Multi-Modal Multi-Array Electrochemical and Optical Sensor Suite for a Biological CubeSat Payload.

CubeSats have emerged as cost-effective platforms for biological research in low Earth orbit (LEO). However, they have traditionally been limited to optical absorbance sensors for studying microbial growth. This work has made improvements to the sensing capabilities of these small satellites by incorporating electrochemical ion-selective pH and pNa sensors with optical absorbance sensors to enrich biological experimentation and greatly expand the capabilities of these payloads. We have designed, built, and tested a multi-modal multi-array electrochemical-optical sensor module and its ancillary systems, including a fluidic card and an on-board payload computer with custom firmware. Laboratory tests showed that the module could endure high flow rates (1 mL/min) without leakage, and the 27-well, 81-electrode sensor card accurately detected pH (71.0 mV/pH), sodium ion concentration (75.2 mV/pNa), and absorbance (0.067 AU), with the sensors demonstrating precise linear responses (R2 ≈ 0.99) in various test solutions. The successful development and integration of this technology conclude that CubeSat bio-payloads are now poised for more complex and detailed investigations of biological phenomena in space, marking a significant enhancement of small-satellite research capabilities.

Neuro-fuzzy system based proportional derivative gain optimized attitude control of CubeSat under LEO perturbations.

Prompt attitude stabilization is more challenging in Nano CubeSat due to its minimal capacity, weight, energy, and volume-constrained architecture. Fixed gain non-adaptive classical proportional integral derivative control methodology is ineffective to provide optimal attitude stability in low earth orbit under significant environmental disturbances. Therefore, an artificial neural network with fuzzy inference design is developed in a simulation environment to control the angular velocity and quaternions of a CubeSat by autonomous gain tuning of the proportional-derivative controller according to space perturbations. It elucidates the dynamics and kinematics of the CubeSat attitude model with reaction wheels and low earth orbit disruptions, i.e., gravity gradient torque, atmospheric torque, solar radiation torque, and residual magnetic torque. The effectiveness of the proposed ANFIS-PD control scheme shows that the CubeSat retained the three-axis attitude controllability based on initial quaternions, the moment of inertia, Euler angle error, attitude angular rate, angular velocity rate as compared to PID, ANN, and RNN methodologies. Outcomes from the simulation indicated that the proposed controller scheme achieved minimum root mean square errors that lead towards rapid stability in roll, pitch, and yaw axis respectively within 20 s of simulation time.

Measuring and Energizing Sensor System for Digital Signal Monitoring of an Academic-Experimental CubeSat for Wireless Telemetry Purposes.

Space technology for small satellites has made significant progress in the academic and industrial fields, and an alternative focused on educational institutions is the CubeSat standard, created to promote various scientific projects of space exploration. In this context, a fundamental module of any satellite is the telemetry subsystem, which controls the communication with the Earth through electronic circuits dedicated to remote communication; also, the measurement and power supply modules are integrated into a CubeSat. Its construction costs range from USD 2500 to 55,000, with suppliers from Europe and the United States. This motivates the development of the present project, aimed at an academic-experimental CubeSat-1U prototype, to limit this technological dependence, focusing on the measurement generated by the acceleration sensors, angular velocity, magnetic fields, barometric pressure, temperature and ultraviolet light intensity, and the energization of each of them. For this, the main objective of the research is to identify the four basic subsystems of the CubeSat-1U: (a) energization subsystem, (b) sensing subsystem, (c) transmission and reception subsystem, and (d) control subsystem. To describe in detail the construction of (a) and (b), a set of diagrams is performed, defining their operation and its interaction. To explain the subsystem's construction, the components selection and integration are presented. As a result, the electrical measurements generated by the power system, the output of the sensors in laboratory conditions, and images of the developed circuits are presented, having as a contribution to the methodology of design, integration, and development of the four subsystems, the feasibility of construction and its implementation in an academic satellite.

Attitude Determination System for a Cubesat Experiencing Eclipse.

In the context of Kalman filters, the predicted error covariance matrix Pk+1 and measurement noise covariance matrix R are used to represent the uncertainty of state variables and measurement noise, respectively. However, in real-world situations, these matrices may vary with time due to measurement faults. To address this issue in CubeSat attitude estimation, an adaptive extended Kalman filter has been proposed that can dynamically estimate the predicted error covariance matrix and measurement noise covariance matrix using an expectation-maximization approach. Simulation experiments have shown that this algorithm outperforms existing methods in terms of attitude estimation accuracy, particularly in sunlit and shadowed phases of the orbit, with the same filtering parameters and initial conditions.

Demonstration of a Modular Prototype End-to-End Simulator for Aquatic Remote Sensing Applications.

This study introduces a prototype end-to-end Simulator software tool for simulating two-dimensional satellite multispectral imagery for a variety of satellite instrument models in aquatic environments. Using case studies, the impact of variable sensor configurations on the performance of value-added products for challenging applications, such as coral reefs and cyanobacterial algal blooms, is assessed. This demonstrates how decisions regarding satellite sensor design, driven by cost constraints, directly influence the quality of value-added remote sensing products. Furthermore, the Simulator is used to identify situations where retrieval algorithms require further parameterization before application to unsimulated satellite data, where error sources cannot always be identified or isolated. The application of the Simulator can verify whether a given instrument design meets the performance requirements of end-users before build and launch, critically allowing for the justification of the cost and specifications for planned and future sensors. It is hoped that the Simulator will enable engineers and scientists to understand important design trade-offs in phase 0/A studies easily, quickly, reliably, and accurately in future Earth observation satellites and systems.

Determination of Greenhouse Gas Concentrations from the 16U CubeSat Spacecraft Using Fourier Transform Infrared Spectroscopy.

Greenhouse gases absorb the Earth's thermal radiation and partially return it to the Earth's surface. When accumulated in the atmosphere, greenhouse gases lead to an increase in the average global air temperature and, as a result, climate change. In this paper, an approach to measuring CO2 and CH4 concentrations using Fourier transform infrared spectroscopy (FTIR) is proposed. An FTIR spectrometer mockup, operating in the wavelength range from 1.0 to 1.7 µm with a spectral resolution of 10 cm-1, is described. The results of CO2 and CH4 observations throughout a day in urban conditions are presented. A low-resolution FTIR spectrometer for the 16U CubeSat spacecraft is described. The FTIR spectrometer has a 2.0-2.4 µm spectral range for CO2 and CH4 bands, a 0.75-0.80 µm range for reference O2 bands, an input field of view of 10-2 rad and a spectral resolution of 2 cm-1. The capabilities of the 16U CubeSat spacecraft for remote sensing of greenhouse gas emissions using a developed FTIR spectrometer are discussed. The design of a 16U CubeSat spacecraft equipped with a compact, low-resolution FTIR spectrometer is presented.

Low-Cost Orientation Determination System for CubeSat Based Solely on Solar and Magnetic Sensors.

CubeSats require accurate determination of their orientation relative to the Sun, Earth, and other celestial bodies to operate successfully and collect scientific data. This paper presents an orientation system based on solar and magnetic sensors that offers a cost-effective and reliable solution for CubeSat navigation. Solar sensors analyze the illumination on each face to measure the satellite's orientation relative to the Sun, while magnetic sensors determine the Earth's magnetic field vector in the satellite's reference frame. By combining the measured data with the known ephemeris of the satellite, the satellite-Sun vector and the magnetic field orientation can be reconstructed. The orientation is expressed using quaternions, representing the rotation from the internal reference system of the satellite to the selected reference system. The proposed system demonstrates the ability to accurately determine the orientation of a CubeSat using only two sensors, making it suitable for installations where more complex and expensive instruments are impractical. Additionally, the paper presents a mathematical model of a low-cost CubeSat orientation system and a hardware implementation of the sensor. The technology, using solar and magnetic sensors, provides a reliable and affordable solution for CubeSat navigation, supporting the increasing sophistication of miniature payloads and enabling accurate satellite positioning in space missions.

Compact UHF Circularly Polarized Multi-Band Quadrifilar Antenna for CubeSat.

This article presents a multi-band right-hand circularly polarized antenna designed for the Cube Satellite (CubeSat). Based on a quadrifilar structure, the antenna provides circular polarization radiation suitable for satellite communication. Moreover, the antenna is designed and fabricated using two 1.6 mm thickness FR4-Epoxy boards connected by metal pins. In order to improve the robustness, a ceramic spacer is placed in the centerboard, and four screws are added at the corners to fix the antenna to the CubeSat structure. These additional parts reduce antenna damage caused by vibrations in the launch vehicle lift-off stage. The proposal has a dimension of 77 × 77 × 10 mm3 and covers the LoRa frequency bands at 868 MHz, 915 MHz, and 923 MHz. According to the measurements in the anechoic chamber, antenna gains with the values of 2.3 dBic and 1.1 dBic are obtained for the 870 MHz and 920 MHz, respectively. Finally, the antenna is integrated into a 3U CubeSat that was launched by a Soyuz launch vehicle in September 2020. The terrestrial-to-space communication link was measured, and the antenna performance was confirmed in a real-life scenario.

Fire reduces eucalypt forest flowering phenology at the landscape-scale.

Plant phenology describes the timing of reproductive events including flowering and fruiting, which for many species are affected by fire disturbance. Understanding phenological responses to fire provides insights into how forest demographics and resources may shift alongside increasing fire frequency and intensity driven by climate change. However, isolating the direct effects of fire on a species' phenology and excluding potential confounders (e.g. climate, soil) has been difficult due to the logistical challenges of monitoring species-specific phenological events across myriad fire and environmental conditions. Here, we use CubeSat-derived crown-scale flowering data to estimate the effects of fire history (time since fire and fire severity over a 15-year time span) on flowering of the eucalypt Corymbia calophylla across a Mediterranean-climate forest (814km2) in southwest Australia. We found that fire reduced the proportion of flowering trees at the landscape-scale, and flowering recovered at a rate of 0.15 % (±0.11% SE) per year. Further, this negative effect was significant due to high crown scorch fires (>20% canopy scorch), yet there was no significant effect from understory burns. Estimates were obtained using a quasi-experimental design which identifies the effect of time since fire and severity on flowering by comparing proportional flowering within target fire perimeters (treatment) and adjacent past fire perimeters (control). Given the majority of fires studied were managed fuel reduction burns, we applied the estimates to hypothetical fire regimes to compare flowering outcomes under more or less frequent prescribed burning. This research demonstrates the landscape-scale effects of burning on a tree species' reproduction, which could broadly impact forest resiliency and biodiversity.

BioSentinel: Validating Sensitivity of Yeast Biosensors to Deep Space Relevant Radiation.

With the imminent human exploration of deep space, it is more important than ever to understand the biological risks of deep space radiation exposure. The BioSentinel mission will be the first biological payload to study the effects of radiation beyond low Earth orbit in 50 years. This study is the last in a collection of articles about the BioSentinel biological CubeSat mission, where budding yeast cells will be used to investigate the response of a biological organism to long-term, low-dose deep space radiation. In this study, we define the methodology for detecting the biological response to space-like radiation using simulated deep space radiation and a metabolic indicator dye reduction assay. We show that there is a dose-dependent decrease in yeast cell growth and metabolism in response to space-like radiation, and this effect is significantly more pronounced in a strain of yeast that is deficient in DNA damage repair (rad51Δ) compared with a wild-type strain. Furthermore, we demonstrate the use of flight-like instrumentation after exposure to space-like ionizing radiation. Our findings will inform the development of novel and improved biosensors and technologies for future missions to deep space.

AstroBio-CubeSat: A lab-in-space for chemiluminescence-based astrobiology experiments.

Space exploration is facing a new era in view of the planned missions to the Moon and Mars. The development and the in-flight validation of new technologies, including analytical and diagnostic platforms, is pivotal for exploring and inhabiting these extreme environments. In this context, biosensors and lab-on-chip devices can play an important role in many situations, such as the analysis of biological samples for assessing the impact of deep space conditions on man and other biological systems, environmental and food safety monitoring, and the search of molecular indicators of past or present life in extra-terrestrial environments. Small satellites such as CubeSats are nowadays increasingly exploited as fast and low-cost platforms for conducting in-flight technology validation. Herein, we report the development of a fully autonomous lab-on-chip platform for performing chemiluminescence-based bioassays in space. The device was designed to be hosted onboard the AstroBio CubeSat nanosatellite, with the aim of conducting its in-flight validation and evaluating the stability of (bio)molecules required for bioassays in a challenging radiation environment. An origami-like microfluidic paper-based analytical format allowed preloading all the reagents in the dried form on the paper substrate, thus simplifying device design and analytical protocols, facilitating autonomous assay execution, and enhancing the stability of reagents. The chosen approach should constitute the first step to implement a mature technology with the aim to conduct life science research in space (e.g., for evaluation the effect of deep space conditions on living organisms or searching molecular evidence of life) more easily and at lower cost than previously possible.

Mind the gap in data poor Natura 2000 sites and how to tackle them using Earth Observation and scientific diving surveys.

Charismatic species drives decisions for the conservation of marine areas in the view of the coverage of the Natura 2000 sites in the European Union and other forms of Marine Protected Areas in Europe. However, when used solely, critical seascapes and habitats are systematically ignored and practically it can take decades to fulfill baseline needs on habitats distributions, habitats conservation status and species distributions and biodiversity assessments. Luckily, in the last decade, the use of new technologies in conjunction with scientific diving and budget friendly hydroacoustic tools and applications, has allowed to fill the gap in knowledge in such situations and seascapes. The current work demonstrates the use of Earth Observation and Science Dive to fill the gap of knowledge in a newly established Natura 2000 area in Crete, Greece, East Mediterranean, paving the road for replicable approaches in similar situations.

Design of 4 × 4 Low-Profile Antenna Array for CubeSat Applications.

This paper presents a low-profile microstrip antenna with high gain for fifth-generation (5G) CubeSat applications. The proposed design consists of 16 miniaturized patch antennas distributed in a uniform 4 × 4 topology with a feeding network on Rogers TMM10 substrate. The antenna array was simulated in CST Studio Suite® software and fabricated for performance testing on the CubeSat structure. The prototype works perfectly from 3.46 GHz to 3.54 GHz. The simulated and measurement results reveal remarkable performance. The design obtained a measured gain of 8.03 dBi and a reflection coefficient of -17.4 dB at the center frequency of 3.5 GHz. Due to its reduced dimensions of 10 × 10 cm, this design is an excellent alternative for mounting on a CubeSat structure as it combines efficient performance with a low profile.

BioSentinel: Long-Term Saccharomyces cerevisiae Preservation for a Deep Space Biosensor Mission.

The biological risks of the deep space environment must be elucidated to enable a new era of human exploration and scientific discovery beyond low earth orbit (LEO). There is a paucity of deep space biological missions that will inform us of the deleterious biological effects of prolonged exposure to the deep space environment. To safely undertake long-term missions to Mars and space habitation beyond LEO, we must first prove and optimize autonomous biosensors to query the deep space radiation environment. Such biosensors must contain organisms that can survive for extended periods with minimal life support technology and must function reliably with intermittent communication with Earth. NASA's BioSentinel mission, a nanosatellite containing the budding yeast Saccharomyces cerevisiae, is such a biosensor and one of the first biological missions beyond LEO in nearly half a century. It will help fill critical gaps in knowledge about the effects of uniquely composed, chronic, low-flux deep space radiation on biological systems and in particular will provide valuable insight into the DNA damage response to highly ionizing particles. Due to yeast's robustness and desiccation tolerance, it can survive for periods analogous to that of a human Mars mission. In this study, we discuss our optimization of conditions for long-term reagent storage and yeast survival under desiccation in preparation for the BioSentinel mission. We show that long-term yeast cell viability is maximized when cells are air-dried in trehalose solution and stored in a low-relative humidity and low-temperature environment and that dried yeast is sensitive to low doses of deep space-relevant ionizing radiation under these conditions. Our findings will inform the design and development of improved future long-term biological missions into deep space.

BioSentinel: A Biological CubeSat for Deep Space Exploration.

BioSentinel is the first biological CubeSat designed and developed for deep space. The main objectives of this NASA mission are to assess the effects of deep space radiation on biological systems and to engineer a CubeSat platform that can autonomously support and gather data from model organisms hundreds of thousands of kilometers from Earth. The articles in this special collection describe the extensive optimization of the biological payload system performed in preparation for this long-duration deep space mission. In this study, we briefly introduce BioSentinel and provide a glimpse into its technical and conceptual heritage by detailing the evolution of the science, subsystems, and capabilities of NASA's previous biological CubeSats. This introduction is not intended as an exhaustive review of CubeSat missions, but rather provides insight into the unique optimization parameters, science, and technology of those few that employ biological model systems.

BioSentinel: A Biofluidic Nanosatellite Monitoring Microbial Growth and Activity in Deep Space.

Small satellite technologies, particularly CubeSats, are enabling breakthrough research in space. Over the past 15 years, NASA Ames Research Center has developed and flown half a dozen biological CubeSats in low Earth orbit (LEO) to conduct space biology and astrobiology research investigating the effects of the space environment on microbiological organisms. These studies of the impacts of radiation and reduced gravity on cellular processes include dose-dependent interactions with antimicrobial drugs, measurements of gene expression and signaling, and assessment of radiation damage. BioSentinel, the newest addition to this series, will be the first deep space biological CubeSat, its heliocentric orbit extending far beyond the radiation-shielded environment of low Earth orbit. BioSentinel's 4U biosensing payload, the first living biology space experiment ever conducted beyond the Earth-Moon system, will use a microbial bioassay to assess repair of radiation-induced DNA damage in eukaryotic cells over a duration of 6-12 months. Part of a special collection of articles focused on BioSentinel and its science mission, this article describes the design, development, and testing of the biosensing payload's microfluidics and optical systems, highlighting improvements relative to previous CubeSat life-support and bioanalytical measurement technologies.

Wideband Versatile Receiver for CubeSat Microwave Front-Ends.

One of the main features of CubeSats is represented by their extreme versatility, e.g., maintaining the same overall structure for different purposes. This requires high technological flexibility achievable in a cost-effective way while maintaining compact sizes. In this contribution, a microwave receiver specifically designed for CubeSat applications is proposed. Due to the wide input operating bandwidth, i.e., 2 GHz-18 GHz, it can be exploited for different purposes, e.g., satellite communication, radars, and electronic warfare systems. This is beneficial for CubeSat systems, whereby the possibility to share the same front-end circuit for different purposes is a key feature in reducing the overall size and weight. The downconverter was designed to minimize the spurious contributions at low frequency by taking advantage, at the same time, of commercial off-the-shelf components due to their cost-effectiveness. The idea behind this work is to add flexibility to the CubeSat communication systems in order to be reusable in different contexts. This feature enables new applications but also provides the largest bandwidth if required from the ground system. An accurate experimental characterization was performed to validate the downconverter performance with the aim of allowing easy system integration for the new frontier of CubeSat technologies. This paves the way for the most effective implementation of the Internet of Things (IoT), machine-to-machine (M2M) communications, and smart-everything services.

On-orbit electrical power system dataset of 1U CubeSat constellation.

This article presents a database containing on-orbit data samples of the Electrical Power System (EPS) from 4 different 1U CubeSats belonging to the BIRDS constellation. The EPS is responsible for providing uninterrupted power to overall satellite both during sunlight and eclipse. The satellites are based on the BIRDS open-source standardized bus designed by Kyutech for research and education. BIRDS bus was used for six satellites that were delivered to ISS on board the Cygnus re-supply spacecraft launched by Antares rocket and released from International Space Station (ISS) into ISS orbit (altitude 400 km, inclination: 51.6°, duration: 92.6 min). The dataset contains the data of voltage (mV), current (mA) and temperature (Celsius) of the battery and solar panels attached to 5 sides of the satellite. This data is collected by the on-board computer every 90 seconds in nominal operation or every 10 seconds in fast sampling mode. The data is downloaded from the satellite memory by the ground station operators. Next, space engineering experts from Kyushu Institute of Technology have analysed the dataset to classify each data sample into normal or anomaly classes. This paper provides one datafile per satellite, that includes data from solar panels and battery since their deployment into orbit until the end of its life for the UGUISU, RAAVANA, and NEPALISAT satellites, first two showing a failure in one of their panels during more than two years of operation on-orbit. The TSURU satellite dataset includes data since its deployment into orbit and will continue to be collected until the end of its life. The dataset generated will be useful for 1U CubeSat, such as BIRDS platform, users, and satellite developers by using it as a reference to compare the behaviour of their Electric Power System under different operating scenarios and align their missions according to the available power on-orbit. At the same time, the dataset can help computer science researchers to build and validate new models for fault diagnosis and outlier detection.

Separation of Spacecraft Noise From Geomagnetic Field Observations Through Density-Based Cluster Analysis and Compressive Sensing.

The use of magnetometers for space exploration is inhibited by magnetic noise generated by spacecraft electrical systems. Mechanical booms are traditionally used to extend magnetometers away from noise sources. If a spacecraft is equipped with multiple magnetometers, signal processing algorithms can be used to compare magnetometer measurements and remove stray magnetic noise signals. We propose the use of density-based cluster analysis to identify spacecraft noise signals and compressive sensing to separate spacecraft noise from geomagnetic field data. This method assumes no prior knowledge of the number, location, or amplitude of noise signals, but assumes that they have minimal overlapping spectral properties. We demonstrate the validity of this algorithm by separating high latitude magnetic perturbations recorded by the low-Earth orbiting satellite, SWARM, from noise signals in simulation and in a laboratory experiment using a mock CubeSat apparatus. In the case of more noise sources than magnetometers, this problem is an instance of underdetermined blind source separation (UBSS). This work presents a UBSS signal processing algorithm to remove spacecraft noise and minimize the need for a mechanical boom.