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The space industry is growing and space data are becoming accessible to businesses that were previously unthinkable. Constellations of small satellites in Very Low Earth Orbit (VLEO) have created a gap that is allowing small and medium-sized space companies to gain momentum by developing new strategies and technologies. According to Euroconsult forecasting, the NewSpace market will grow from $12.6 billion to $42.8 billion in the next decade (2019–2028). Despite the study’s limitations and the uncertainties of the small satellite market, the results obtained in this exploratory research suggest that the Low-Cost Carriers (LCC) market, an already established market in the aviation industry, and the growing market of EO small satellite constellations in VLEO have similar behaviours. This behaviour shows that the evolution of EO smallsat constellations in VLEO is comparable with the evolution of the LCC airlines. In addition, the result also identifies a set of competitive factors that allow the researchers to observe similar strategic behaviour in both markets Peer Reviewed Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura

The Satellite for Orbital Aerodynamics Research (SOAR) is a 3U CubeSat mission that aims to investigate the gas–surface interactions (GSIs) of different materials in the very low Earth orbit environment (VLEO), i.e. below 450 km. Improving the understanding of these interactions is critical for the development of satellites that can operate sustainably at these lower orbital altitudes, with particular application to future Earth observation and communications missions. SOAR has been designed to perform the characterisation of the aerodynamic coefficients of four different materials at different angles of incidence with respect to the flow and at different altitudes in the VLEO altitude range. Two conventional and erosion-resistant materials (borosilicate glass and sputter-coated gold) have first been selected to support the validation of the ground-based Rarefied Orbital Aerodynamics Research (ROAR) facility. Two further, novel materials have been selected for their potential to reduce the drag experienced in orbit whilst also remaining resistant to the detrimental effects of atomic oxygen erosion in VLEO. In this paper, the uncertainty associated with the experimental method for determining the aerodynamic coefficients of satellite with different configurations of the test materials from on-orbit data is estimated for different assumed gas–surface interaction properties. The presented results indicate that for reducing surface accommodation coefficients the experimental uncertainty on the drag coefficient determination generally increases, a result of increased aerodynamic attitude perturbations. This effect is also exacerbated by the high atmospheric density at low orbital altitude (i.e. 200 km), resulting in high experimental uncertainty. Co-rotated steerable fin configurations are shown to provide generally lower experimental uncertainty than counter-rotated configurations, with the lowest uncertainties expected in the mid-VLEO altitudes ($$\sim$$ ∼ 300 km). For drag coefficient experiments, configurations with two fins oriented at 90$$^{\circ }$$ ∘ were found to allow the best differentiation between surfaces with different GSI performance. In comparison, the determination of the lift coefficient is found to be improve as the altitude is reduced from 400 to 200 km. These experiments were also found to show the best expected performance in determining the GSI properties of different materials. SOAR was deployed into an orbit of 421 km $$\times$$ × 415 km with 51.6$$^{\circ }$$ ∘ inclination on 14 June 2021. This orbit will naturally decay allowing access to different altitudes over the lifetime of the mission. The results presented in this paper will be used to plan the experimental schedule for this mission and to maximise the scientific output.

Basic performances of the acousto-optical cells, which can be potentially involved into creating a novel triple-product acousto-optical processor for modern astrophysical applications, are under estimation. The main attention is paid to the time-bandwidth product, because just this parameter can be taken as the most general one for the characterization of performance data inherent in each individual cell. Functional capabilities peculiar to the cells operating over either normal or anomalous light scattering regime are under consideration. Evidently, the anomalous regime of light scattering promises better results. Both the theoretical estimations and the experimental data obtained for a large-aperture acousto-optical cell based on a tellurium dioxide crystal, exploiting the anomalous light scattering, gives the time-bandwidth product equal to about 4000 .

It is well known that an appropriate apodization of the light beam within acousto-optical data processing makes it possible to increase the potential dynamic range of a system up to 40 dB and more. Customary, the Gaussian apodization is used when a light beam incidents on a rectangular uniform operative aperture of acousto-optical cell. However, modern acousto-optics exploits often rather high-frequency radio-wave signals in a view of increasing the frequency bandwidth by itself or/and growing the time-bandwidth product inherent in a cell. Anyway, similar acoustooptical cells operate with such frequencies that acoustic losses become already pronounced, so that the effect of these losses along an aperture of a cell has to be taken into account. Typically, acceptable level of the acoustic losses accounts about 3 − 6 dB per cell’s aperture. By this it means that the expected no-uniformity of distributing the acoustic energy is now not negligible. To obtain really optimized profile of the incident light beam apodization the expected influence of acoustic losses ought to be analyzed and estimated. In connection with aforementioned no-uniformity or asymmetry, one can propose exploiting a quasi-Gaussian profile of the incident light beam reasonably shifted relative to the center of an aperture of the acousto-optical cell with appreciable acoustic losses.

Rather specific types of light diffraction in the condensed matters are analyzed theoretically, so that in fact a set of processes conditioned by a multi-phonon light scattering in the Bragg regime is under investigation. Besides of their scientific novelty, studying these phenomena promises real progress in applications, because practical exploiting of the m - phonon processes in frontier schemes for the acousto-optical spectrum analysis of both optical and radio-signals leads potentially to improving the frequency and/or spectral resolution of the corresponding analyzers by almost m - times. With this in mind, the wave-based description, the corpuscular approach as well as the quantum interpretation of acousto-optical interaction are used here to characterize various aspects related to improving the expected resolution of acousto-optical devices exploiting a multi-phonon light scattering. In so doing, the quantity of orders under consideration is limited by number N ≤ 4 , which is still hopefully possible to be achieved experimentally in Bragg regime. Additionally, a brief description of a multi-order light scattering by usual thin diffraction grating is presented in the appendix for the convenience of its physical comparison with the results obtained for acousto-optics.

Both a high level of developing the spatially spot-like and one-dimensional input devices and the flexibility of a design inherent in two-dimensional optical systems with similar modulating components make it possible to realize various high-bit-rate opto-electronic processors. This is why a one-dimension acousto-optic technique has been involved in data processing and its modeling based on the algorithm of triple product correlations. Practically, triple product correlations originate within an optical scheme including the modulated light source, representing the first input port, and two wideaperture acousto-optical cells forming two other input ports. Due to specifically constructed lens system, initially modulated light beam is crossing sequentially the apertures of acousto-optical cells oriented at right angle to each other. Finally, a CCD-matrix integrates the received optical signal with respect to time and registers the resulting triple product correlations. In a view of arranging similar acousto-optical processor for modeling triple product correlations, we characterize a novel version of the acousto-optical cells exploiting now tellurium-dioxide crystals. Together with this, potential performances of the progressed design for similar processor are estimated as well.

Some practical aspects of creating an acousto-optical processor oriented to the calculation of triple auto- and cross-correlations of low-power short optical pulses in time domain are under preliminary consideration. In so doing, the shapes of both the triple auto-correlations and the bispectra inherent in the most commonly used pulses are mathematically expressed and numerically illustrated, and the needed general schematic arrangement for a triple correlation acousto-optical processor is designed and briefly discussed. Then, in a view of exploiting the one-channel wide-aperture acousto-optical cells within operating similar processor, the performances of lead-molybdate crystalline cells are tentatively estimated.

A business roadmap is a high-level strategic management tool that maps the actions to develop new industries. It serves as a guide to plan and forecast technological, market and product developments in a more operational way. Precisely, the business roadmap of this article highlights the main actions to be taken by the European Union (EU) space ecosystem with regards to Low Earth Orbit (LEO)—orbits from 450 to 2000 km—and Very Low Earth Orbit (VLEO)—orbits from 150 to 450 km. On the one hand, it is necessary to (1) develop industrial and technological space capabilities, (2) continue investing public funds in European Programs to develop new vehicle concepts of access to space, (3) improve testing, demonstration and exploration for faster the Technology Readiness Level (TRL) development, (4) promote an entrepreneurial and risk-taking culture, and (5) leverage the private investment to boost the development of advanced access to space technologies, attract talent, promote collaboration between public and private companies, and finance NewSpace Small–Medium sized Enterprises (SMEs). On the other hand, it should also strengthen its relationship with the European Space Agency (ESA) to foster its space capabilities and become a competitive player in the access to space market in the medium term (5–10 years). The implementation of these actions will help the EU to improve its international positioning, and adapt the technology to the needs and requirements of NewSpace demand, mobilizing around €40,500 million euros for the EU economy during the first 10–15 years of operations with an average Leverage Factor (LF) of 4 Peer Reviewed Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura

DISCOVERER is a European Commission funded project aiming to revolutionise satellite applications in Very Low Earth Orbits (VLEO). The project encompasses many different aspects of the requirements for sustainable operation, including developments on geometric designs, aerodynamic attitude and orbital control, improvement of intake designs for atmosphere breathing electric propulsion, commercial viability, and development of novel materials. This paper is focused solely on the description of the experimental facility designed and constructed to perform ground testing of materials, characterising their behaviour in conditions similar to those found in VLEO. ROAR, Rarefied Orbital Aerodynamics Research facility, is an experiment designed to provide a controlled environment with free molecular flow and atomic oxygen flux comparable to the real orbital environment. ROAR is a novel experiment, with the objective of providing better and deeper understanding of the gas-surface interactions between the material and the atmosphere, rather than other atomic oxygen exposure facilities which are mainly focused on erosion studies. The system is comprised of three major parts, (i) ultrahigh vacuum setup, (ii) hyperthermal oxygen atom generator (HOAG) and (iii) ion-neutral mass spectrometers (INMS). Each individual part will be considered, their performance analysed based on experimental data acquired during the characterisation and commissioning, thus leading to a complete description of ROAR’s capabilities. Among the key parameters to be discussed are operational pressure, atomic oxygen flux, beam shape and energy spread, mass resolution, signal-to-noise ratio and experimental methodology.

We present the validation of ADBSat, a novel implementation of the panel method including a fast pseudo-shading algorithm, that can quickly and accurately determine the forces and torques on satellites in free-molecular flow. Our main method of validation is comparing test cases between ADBSat, the current de facto standard of direct simulation Monte Carlo (DSMC), and published literature. ADBSat exhibits a significantly shorter runtime than DSMC and performs well, except where deep concavities are present in the satellite models. The shading algorithm also experiences problems when a large proportion of the satellite surface area is oriented parallel to the flow, but this can be mitigated by examining the body at small angles to this configuration (${\pm}$ 0.1{\deg}). We recommend that an error interval on ADBSat outputs of up to 3\% is adopted. Therefore, ADBSat is a suitable tool for quickly determining the aerodynamic characteristics of a wide range of satellite geometries in different environmental conditions in VLEO. It can also be used in a complementary manner to identify cases that warrant further investigation using other numerical-based methods., Comment: 30 pages, 15 figures. Submitted to Computer Physics Communications