One of the main challenges to be faced in deep space missions is to protect the health and ensure the maximum efficiency of the crew by preparing methods of prevention and in situ diagnosis. Indeed, the hostile environment causes important health problems, ranging from muscle atrophy, osteopenia, and immunological and metabolic alterations due to microgravity, to an increased risk of cancer caused by exposure to radiation. It is, therefore, necessary to provide new methods for the real-time measurement of biomarkers suitable for deepening our knowledge of the effects of space flight on the balance of the immune system and for allowing the monitoring of the astronaut’s health during long-term missions. APHRODITE will enable human space exploration because it fills this void that affects both missions in LEO and future missions to the Moon and Mars. Its scientific objectives are the design, production, testing, and in-orbit demonstration of a compact, reusable, and reconfigurable system for performing the real-time analysis of oral fluid samples in manned space missions. In the frame of this project, a crew member onboard the ISS will employ APHRODITE to measure the selected target analytes, cortisol, and dehydroepiandrosterone sulfate (DHEA-S), in oral fluid, in four (plus one additional desired session) separate experiment sessions. The paper addresses the design of the main subsystems of the analytical device and the preliminary results obtained during the first implementations of the device subsystems and testing measurements on Earth. In particular, the system design and the experiment data output of the lab-on-chip photosensors and of the front-end readout electronics are reported in detail along with preliminary chemical tests for the duplex competitive CL-immunoassay for the simultaneous detection of cortisol and DHEA-S. Different applications also on Earth are envisaged for the APHRODITE device, as it will be suitable for point-of-care testing applications (e.g., emergency medicine, bioterrorism, diagnostics in developing countries, etc.).
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.
Preliminary results of the in-orbit characterization of an analytical payload based on a lab-on-chip device with integrated thin-film photosensors relying on chemiluminescence immunoassay is presented. The paper addresses the characterization of the main components of the analytical system based on data acquired during the AstroBio CubeSat mission launched aboard the Vega-C maiden flight in summer 2022. In particular, the performances of the on-chip thin-film sensors and the lab-on-chip front-end readout electronics are reported in detail confirming the suitability of the proposed technology for space application.
Small satellites are known to provide low-cost access to space, enabling fast and cheap validation of new technologies for space missions. ASTROBIO is a 3U CubeSat (size 100xl00x300 mm3), that was injected into an orbit crossing several times a day the cloud of radiation known as the Van Allen Belts. As a result, the solar panels are exposed to an enhanced dose rate and undergo in a few days the same degradation that would be observed after several years of space flight in Low Earth Orbit. We used this unique opportunity to validate the new End-Of-Life optimized Triple Junction solar cells (CTJ-EOL) produced in Italy by CESI. The spacecraft solar panel comprises two types of solar cells produced by the same manufacturer: the well-established CTJ-30 and the new CTJ-EOL. Their performance was separately monitored and the related telemetries were downloaded for off-line elaboration. This manuscript reports and analyses the telemetries received by our Ground Station and by the networked stations distributed all over the globe. Data analysis clearly and unequivocally demonstrated the superior ruggedness of the End-Of-Life optimized devices: in the first week, the CTJ-30 performance dropped like it would be expected along a 10-years+ mission in the most-commonly-used orbits, whereas degradation of the CTJ-EOL was barely detectable. The results also show that in-orbit testing can provide unique information about the operation of solar cells in the intended operational environment as well as an easy verification of the device's functionality, useful to complement standard characterization procedures for radiation hardness involving costly and time-consuming laboratory tests under particle beams.
AstroBio CubeSat is a mission funded by the Italian Space Agency aimed at validating novel lab-on-chip technology, that would enable the use of micro- and nanosatellites as autonomous orbiting laboratories for research in astrobiology. This 3U CubeSat is equipped with a passive magnetic attitude control system (PMACS), including permanent magnets and hysteresis strips, which allows for stabilizing the spacecraft with the longitudinal axis in the direction of the geomagnetic field vector. This work presents the process followed for the experimental characterization of the system, performed on the engineering unit of the satellite by using a Helmholtz cage facility and a spherical air-bearing to recreate environmental conditions similar to the ones experienced during the orbital motion. The hysteresis strips are characterized starting from the determination of the hysteresis loop, from which the energy dissipation per cycle and the apparent magnetic permeability are extracted. Tests performed by using the Helmholtz cage and the air-bearing facility allows for further investigating the damping torque produced by the PMACS and validating the abovementioned parameters. Numerical analysis is then used to select the number of permanent magnets which allows for achieving a pointing accuracy within an error of 10∘ within 24 h from the deployment. The analysis of the flight data supports the results obtained from the experimental test campaigns, confirming the effectiveness of the proposed methods and of the PMACS design.