Summary
The space environment is still challenging but is becoming more and more attractive for an increasing number of entities. In the second half of the 20th century, a huge amount of funds was ...required to build satellites and gain access to space. Nowadays, it is no longer so. The advancement of technologies allows producing very small hardware components able to survive the strict conditions of the outer space. Consequently, small satellites can be designed for a wide set of missions keeping low design times, production costs, and deployment costs. One widely used type of small satellite is the CubeSat, whose different aspects are surveyed in the following: mission goals, hardware subsystems and components, possible network topologies, channel models, and suitable communication protocols. We also show some future challenges related to the employment of CubeSat networks.
A brief general survey on small satellites and CubeSats is provided, touching mission goals, hardware subsystems and components, network topologies, channel models, and communication protocols. Future challenges and open issues are pointed out.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Given the increasing number of space-related applications, research in the emerging space industry is becoming more and more attractive. One compelling area of current space research is the design of ...miniaturized satellites, known as CubeSats, which are enticing because of their numerous applications and low design-and-deployment cost. The new paradigm of connected space through CubeSats makes possible a wide range of applications, such as Earth remote sensing, space exploration, and rural connectivity. CubeSats further provide a complementary connectivity solution to the pervasive Internet of Things (IoT) networks, leading to a globally connected cyber-physical system. This paper presents a holistic overview of various aspects of CubeSat missions and provides a thorough review of the topic from both academic and industrial perspectives. We further present recent advances in the area of CubeSat communications, with an emphasis on constellation-and-coverage issues, channel modeling, modulation and coding, and networking. Finally, we identify several future research directions for CubeSat communications, including Internet of space things, low-power long-range networks, and machine learning for CubeSat resource allocation.
CubeSats are a class of miniaturized satellites that have become increasingly popular in academia and among hobbyists due to their short development time and low fabrication cost. Their compact size, ...lightweight characteristics, and ability to form a swarm enables them to communicate directly with one another to inspire new ideas on space exploration, space-based measurements, and implementation of the latest technology. CubeSat missions require specific antenna designs in order to achieve optimal performance and ensure mission success. Over the past two decades, a plethora of antenna designs have been proposed and implemented on CubeSat missions. Several challenges arise when designing CubeSat antennas such as gain, polarization, frequency selection, pointing accuracy, coverage, and deployment mechanisms. While these challenges are strongly related to the restrictions posed by the CubeSat standards, recently, researchers have turned their attention from the reliable and proven whip antenna to more sophisticated antenna designs such as antenna arrays to allow for higher gain and reconfigurable and steerable radiation patterns. This paper provides a comprehensive survey of the antennas used in 120 CubeSat missions from 2003 to 2022 as well as a collection of single-element antennas and antenna arrays that have been proposed in the literature. In addition, we propose a pictorial representation of how to select an antenna for different types of CubeSat missions. To this end, this paper aims is to serve both as an introductory guide on CubeSats antennas for CubeSat enthusiasts and a state of the art for CubeSat designers in this ever-growing field.
As small satellites become more popular and capable, strategies to provide in-space propulsion increase in importance. Applications range from orbital changes and maintenance, attitude control and ...desaturation of reaction wheels to drag compensation and de-orbit at spacecraft end-of-life. Space propulsion can be enabled by chemical or electric means, each having different performance and scalability properties. The purpose of this review is to describe the working principles of space propulsion technologies proposed so far for small spacecraft. Given the size, mass, power, and operational constraints of small satellites, not all types of propulsion can be used and very few have seen actual implementation in space. Emphasis is given in those strategies that have the potential of miniaturization to be used in all classes of vehicles, down to the popular 1-L, 1-kg CubeSats and smaller.
This paper focuses on the optimal design of a modulated retroreflector (MRR) laser link to establish a high-speed downlink for cube satellites (CubeSats), taking into account the weight and power ...limitations commonly encountered by these tiny satellites. To this end, first, a comprehensive channel modeling is conducted considering key real channel parameters including mechanical gimbal error, fast steering mirror angle error, laser beamwidth, MRR area, atmospheric turbulence, and channel coherence time. Accordingly, a closed-form expression for the distribution of the received signal is derived and utilized to propose a maximum likelihood based method to sense and estimate the initial position of the satellite. Subsequently, the distribution of the distance estimation error during the sensing phase is formulated as a function of the laser beamwidth and the gimbal error, which enables us to fine-tune the optimal laser beamwidth to minimize sensing time. Moreover, using the sensing and initial satellite distance estimation, two positioning algorithms are proposed. To compare the performance of the proposed positioning method, we obtain the lower bound of the positioning error as a benchmark. Finally, by providing comprehensive simulations, we evaluate the effect of different parameters on the performance of the considered MRR-based system in both the sensing and positioning phases.
A Comprehensive Review on Small Satellite Microgrids Yaqoob, Mohammad; Lashab, Abderezak; Vasquez, Juan C. ...
IEEE transactions on power electronics,
2022-Oct., 2022-10-00, Volume:
37, Issue:
10
Journal Article
Peer reviewed
Open access
The small satellite (SmallSat) industry has recorded incredible growth recently. Within this class, among mini-, micro-, and nanosatellites, the cube satellite (CubeSat) is primed for an explosion of ...growth. These satellites are fascinating for remote sensing, Earth observation, and scientific applications. Remarkable attention from the space operators makes it valuable because of its low cost, cubic shape, less manufacturing time, lightweight, and modular structure. Among the various subsystems comprising the SmallSat, the electrical power system (EPS) is the most crucial one because unreliable power supply to the rest is most of the time detrimental to the mission. The EPS is formed by electrical sources, storage units, and loads, all interconnected via different power converters, the operation of which must be closely orchestrated to accomplish efficient use of photovoltaic power, optimal battery management, and resilient power delivery. At the same time, the EPS design must address a series of challenges such as size restrictions, high power density, and harsh space environments (e.g., atomic oxygen, radiation, and extreme temperatures), which significantly impact the EPS electrical and electronic equipment. In terms of power systems, a SmallSat EPS can be considered a space microgrid owing to coordination and control of distributed generation, storage, and loads in a small-scale electrical network. From this point of view, this article reviews and explores SmallSat microgrid's research developments, energy transfer and architectures, converter topologies, latest technologies, main challenges, and some potential solutions, which will enable building a more robust, resilient, and efficient EPS. The research gaps and future developments are underlined before this article is concluded.
•The risk to spacecraft from impact damage by space debris is characterised by debris size and shown to peak at 1–10 mm.•Use of CubeSats to host impact detectors for 1 mm size debris is shown to be ...feasible and cost-effective.•The impact detector technologies available for use on CubeSats are summarised.
Impacts on spacecraft by mm-sized debris in Earth orbit can have severe consequences including loss of a spacecraft and generation of more debris. This hazard and potential mitigation are discussed herein, and the risk of an impact (the product of flux and damage) is found vs. size. Reduction of the future flux of mm-sized debris by de-orbiting life-expired space vehicles, only reduces, not eliminates, this hazard. It is thus vital that the flux of mm-sized objects in orbit is well defined, but this requires on-orbit determination. To provide statistically meaningful debris flux data, large detection areas are traditionally required. CubeSats could host debris detectors, but only have small surface areas, and the data from many would be required. Accordingly, flux data from historic small space exposed surfaces are compared herein to MASTER flux model predictions, with good agreement for exposure times of just a few years, demonstrating a viable method to determine the debris flux. The cost of a network of CubeSat mounted impact detectors is also estimated found, and, for fleets of order 100 CubeSats, is comparable to the traditional single large satellite mounted instrument.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Retrogressive thaw slumps (RTSs) are among the most dynamic landforms in permafrost areas, and their formation can be attributed to the thawing of ice-rich permafrost. The spatial distribution and ...impacts of RTSs on the Tibetan Plateau are poorly understood due to their remote location and the technical challenges of automatic mapping. In this study, we innovatively applied DeepLabv3+, a cutting-edge deep learning algorithm for semantic segmentation, to Planet CubeSat images, which are satellite images with high spatial and temporal resolution. Our method allows us to automatically delineate 220 RTSs within an area of 5200 km2 with an average precision of 0.541. The corresponding precision, recall, and F1 score are 0.863, 0.833, and 0.848 respectively, when the threshold of intersection over union is 0.5. Moreover, approximately 100 experiments on k-fold cross-validation (k = 3, 5, and 10) and data augmentation show that our method is robust. And a test in a different geographic area shows that the generalization of the trained model is very good. We find that (1) most of the RTSs are small (areas < eight ha and perimeters < 2000 m) and (2) RTSs preferentially develop at locations with gentle slopes (four to eight degrees), and in areas lower than the surroundings (the mean topographic position index is −0.17) and receiving less solar radiation (i.e., north-facing slopes). The results show that the method can map RTSs automatically from Planet CubeSat images and can potentially be applied to larger areas.
•The first automated mapping of retrogressive thaw slumps (RTS) on Tibetan Plateau.•The method successfully delineates small and obscure RTSs from CubeSat Images.•Robustness of the method is proved by approximately 100 independent experiments.•Data augmentation improves delineation accuracies but introduces false positives.•Analysis reveals that RTSs tend to initiate at locations lower than the surroundings.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
