CubeSat Class Research Articles

Model-based controllers for CubeSat ORU installation: A comparative study

The increasing space debris population in critical orbits due to spacecraft failure dictates the need for action. On-Orbit Servicing (OOS) has been proposed as a method for mitigating this trend by repairing existing space assets. The development of large servicing spacecraft has been given significant attention. In this paper, we are approaching the problem with a new paradigm for a servicing spacecraft by proposing a CubeSat class servicer equipped with a one-degree-of-freedom (DoF) robotic arm. Considering the OOS context, we choose the Orbital Replacement Unit (ORU) installation on a target spacecraft as a challenging benchmark task for the proposed servicer configuration. To carry out this task, we formulate and compare performance of four controllers to achieve coordinated control of both the CubeSat and the robotic arm for the installation task. We start with a basic PD controller and progress to the more advanced impedance controller, Model Predictive Control (MPC) and Model Predictive Impedance Control (MPIC) designs. The controllers are evaluated and compared across several relevant metrics for the ORU installation and their merits for practical implementation are discussed.

Багатокритеріальне оцінювання стандартизованих інтерфейсів бортових мереж наносупутників CubeSat

The technology of building CubeSat-class nanosatellites has created a breakthrough in exploring near space for research and education. The availability of commercial solutions for the rapid integration of hardware and software of a CubeSat under development and the launch of such a nano-satellite into Earth orbit as a parasitic payload has made this technology accessible and attractive to universities worldwide. Despite this popularity, the statistics of nanosatellite failures after launch require a systematic approach to their design and construction and the selection of off-the-shelf (COTS) components. The object of the study is to determine the overall efficiency of standardized network interfaces when used in the onboard network of CubeSat nanosatellites. The subject of the article is a method for comprehensively evaluating the effectiveness of standardized network interfaces for data exchange in the onboard network of CubeSat nanosatellites, taking into account typical scenarios for data and command exchange. The aim of the study was to substantiate the method of expert evaluation of the technical efficiency of standardized network interfaces for data exchange in the onboard network of CubeSat nanosatellites, taking into account the following factors: energy efficiency, multi-mastering capability, resistance to electromagnetic interference, redundancy, coverage following the OSI network model, data transmission speed, and complexity of network technology implementation by software. Objectives: To analyze modern methods of organizing onboard avionics networks of nanosatellites of the CubeSat class, formulate an expert comparison model, and compare the selected information onboard networks following the model and the list of selected networks and their protocols. Results: an expert model consisting of a 7-factor comparison was created, modern and most widely used in the industry onboard networks were selected, and each network was compared according to the proposed model. Conclusions: The two most common and efficient models, I2C and CAN, were selected as recommended for use in the avionics of the KhAI1Sat nanosatellite and the “Boryviter”/”Falco” onboard computer being developed by the authors. Although the difference in power consumption between these two types of networks is significant, each has certain advantages in terms of noise immunity, multicasting, and application.

A Tailored Systems Engineering Process for Developing Student-Built CubeSat Class Satellites

A Tailored Systems Engineering Process for Developing Student-Built CubeSat Class Satellites

Estimation of the possibility of matching the relative motion of nanosatellites under active aerodynamic control

The article discusses the prospects of utilization of aerodynamic control to maintain the formation of nanosatellites of the CubeSat class. The purpose of this work is to estimate the limits of the application of active aerodynamic control to stabilize the relative motion of two CubeSat 3U satellites in a sun-synchronous orbit with a height of 570 km. A review of theoretical information about aerodynamic forces acting on artificial Earth satellites is carried out, within the framework of which models of the Earth's upper atmosphere are considered. Aspects of creating a differential drag force for nanosatellites as an active control actuating mechanism are considered. To study the orbital motion of satellites under the action of aerodynamic control using the General Mission Analysis Tool program, a group flight of two spacecraft was simulated taking into account the factors causing orbital disturbances. Based on the results of experiments, the dynamics of the inter-satellite distance was studied, and a conclusion was made about the possibility of using an aerodynamic differential force to achieve a stable relative motion.

Ключевые вопросы создания надувных тормозных устройств для увода вышедших из строя спутников в плотные слои атмосферы. Часть 1. Проектный облик. Движение в разреженной атмосфере

Development of the near-Earth space is accompanied by space debris appearing in the near-Earth orbits and consisting of artificial satellites, elements of other spacecraft, launch vehicles and upper stages with the exhausted resource. High activity of enthusiasts creating nanosatellites of the CubeSat class forces to make gloomy forecasts of space pollution. To clean the near-Earth space from debris, a variety of projects is proposed that provide for collection of the already accumulated debris and equipping the new generation of rocket and space systems with means for transferring to the burial orbits or into the atmosphere dense layers. Promising means of eliminating space debris include inflatable braking devices designed to transfer the fastened objects into the atmosphere dense layers. The braking device temperature state is formed under the influence of thermal radiation flows from the Sun and the Earth and kinetic heating caused by motion in the rarefied atmosphere. The paper considers options of the conceptual design of an inflatable braking device for nanosatellites of the CubeSat class positioned in the low Earth orbits. Results are provided of simulating motion of the thin-walled spherical shell of the inflatable braking device. Duration of reaching the atmosphere dense layers was estimated.

A Morphing Deployable Mechanism for Re-Entry Capsule Aeroshell

Morphing technology is increasingly emerging as a novel and alternative approach for performing the controlled re-entry and precise landing of space vehicles by using adaptive aeroshell structure designs. This work is intended as a preliminary conceptual design of an innovative shape-changing mechanism for the controlled re-entry and safe recovery of CubeSat class systems aimed at recovering payloads and data from LEO at low cost for post flight inspections and experimentations. Such an adaptive and mechanically deployable aeroshell consists of a multi-hinge assembly based on a set of finger-like articulations having two-modal capabilities. The deployable surface can be modulated by a single translational actuator in order to adapt the lift-to-drag ratio for guided entry. Furthermore, once deployed, the system can activate eight small movable aerodynamic flaps that can be individually morphed via an SMA-based actuation to enhance the capsule maneuverability during the re-entry trajectory, by using exclusively aerodynamic forces to guarantee additional precision in landing. Multi-body simulations on retraction/deployment of the system are addressed to investigate the most critical aspects for actual implementation of the concept. Additionally, the morphing behavior and the control effect of the shape memory alloy actuation are preliminary assessed through parametric analysis. This paper is framed within a scientific cooperation between Italy and Brazil in the framework of the SPLASH project, funded in part for the Italian side by a grant from the Italian Ministry of Foreign Affairs and International Cooperation (MAECI), and by CONFAP through the involved State Funding Agencies (FAPs) for the Brazilian side.

Study of the Two-Line Element Accuracy by 1U CubeSat with a GPS Receiver.

There is a common practice to calculate orbital trajectories of space objects like satellites and space debris using Two-Line Element Sets (TLEs). However, TLEs provide rather coarse parameters for fine orbit computation and their precision varies with age of their issue and position of the satellite. The paper evaluates such induced position determination error using the comparison of a position calculated from TLE data for a small CubeSat class satellite and a position obtained from the on-board custom GPS receiver that is a part of such satellite payload. The analyses of the impact of satellite position at the orbit, i.e., a dependency of position error on satellite geographical latitude, and impact of the ageing of TLE data in frame of position and velocity vector were made. There was shown that use of TLE data can bring some significant errors in calculation of predicted satellite position which can affect performance and efficiency of some related tasks like steering the ground station antenna for communication with the satellite or planning the satellites operations namely for the classes of small and amateur satellites.

Satellite temperature measurement in LEO and improvement method of temperature sensors calibration based on the measured data

AbstractThis article describes the temperature measurement and its calibration on board of the nanosatellite CubeSat class VZLUSAT‐1. There are several thermometers, installed with an analog and a digital output, which are necessary for the accurate measurements calibrations under a vacuum condition or for applying postprocessing corrections. This document describes the way of calibration in a thermal vacuum chamber and its improvement in orbit. In addition, this article will discuss the use of a resistance temperature detector platinum sensors Pt1000 and a digital sensors HYT271 as the reference. A correction variable based on HYT271 compensates a nonlinearity of Pt1000 as well as minimizes the influence of change in a measuring current due to temperature changes. The current correction variable is a function of temperature and nanosatellite's position in the orbit. The measured temperatures are below −70°C in the Earth's shadow and greater than +80°C after irradiation by the Sun. Orbital temperature calibration is performed in two steps. The raw temperature data obtained during the orbital measurement are being used for further improvement. The measurement cycle consists of the electronics calibration, temperature measurement, and temperature calibration. After applying the temperature correction process, the final accuracy becomes better than ±0.15°C.

A material experiment for small satellites to characterise the behaviour of carbon nanotubes in space – development and ground validation

Over the last years, Carbon Nanotubes (CNT) drew interdisciplinary attention. Regarding space technologies a variety of potential applications were proposed and investigated. However, no complex data on the behaviour and degradation process of carbon nanotubes under space environment exist. Therefore, it is necessary to investigate the performance of these new materials in space environment and to revaluate the application potential of CNTs in space technologies.Hence, CiREX (Carbon Nanotubes – Resistance Experiment) was developed as a part of a student project. It is a small and compact experiment, which is designed for CubeSat class space satellites. These are a class of nanosatellites with a standardized size and shape. The CiREX design, electrical measurements and the satellites interfaces will be discussed in detail. CiREX is the first in-situ space material experiment for CNTs.To evaluate the data obtained from CiREX, ground validation tests are mandatory. As part of an extensive test series the behaviour of CNTs under solar ultra violet light (UV) and vacuum ultraviolet light (VUV) was examined. Single-walled carbon nanotubes (SWNT), multi-walled carbon nanotubes (MWNT) and MWNT/resin composite (ME) were exposed to different light sources. After the exposure, the defect density was investigated with Raman spectroscopy. There is a clear indication that UV and VUV light can increase the defect density of untreated CNTs and influence the electrical behaviour.

Revisiting the configuration of small satellites structures in the framework of 3D Additive Manufacturing

In this paper the AM-induced evolution of the design process for small satellites is investigated, leading to the identification of optimal design strategies and the definition of a new MAIT concept. A review of the open literature is presented and some introductory concepts are exposed to highlight the effect of the introduction of AM technologies in the development of new satellites systems. In particular, an innovative structural configuration for the CubeSat class of satellites is proposed, with the ultimate goal of minimizing system complexity via parts reduction and the integration of subsystems through an innovative assembly configuration, as an example to be considered for larger satellites.

Определение направления на местную вертикаль для наноспутника класса CubeSat по анализу изображений Земли

Определение направления на местную вертикаль для наноспутника класса CubeSat по анализу изображений Земли

Nanosatellite orbit control using MEMS cold gas thrusters

We introduce nanosatellite orbit control using a novel miniaturized cold gas propulsion module based on microelectro- mechanical systems (MEMS) technology. Firstly, the design and characteristics of the propulsion module suitable for CubeSat class nanosatellites are described. Secondly, mission analyses for in-orbit validation of the propulsion module on a 2-unit CubeSat in 300 km low Earth orbit are presented. The MEMS cold gas propulsion module with 10 cm £ 10 cm £ 3 cm dimensions and 220 g mass is specifically designed for use in CubeSats. In baseline configuration with a tank for 60 g of butane under 2 to 5 bar pressure, it can provide up to 15 m/s delta-V capability for a 2.66 kg satellite. The module includes four individually controllable thrusters with proportional thrust regulation and closed loop control; maximum thrust is 1 mN per thruster with 5 N thrust resolution. The fully operational satellite with active orbital control is capable of accommodating a 0.64 kg and 10 cm £ 10 cm £ 7 cm additional payload. The analysed mission scenarios have potential for different Earth observation applications. Natural deorbiting, controlled orbit lowering, controlled orbit raising, and orbit keeping at 300 km altitude are simulated. Simulations indicate that the natural orbit lifetime can be extended from 63 days to 193 days with the baseline propulsion module and satellite altitude can be increased to 348 km or lowered to 257 km. Orbit keeping at 300 km is possible for up to 76 days; proportional thrust control could provide a further increase to 204 days.

CubeSats: A bright future for nanosatellites

AbstractInterest in the CubeSat class of nanosatellites has surged in recent years. The reduced development time and launch cost of these platforms, compared to conventional large satellites, have made them attractive for applications ranging from technology demonstrations to biological experiments to space weather research. This paper surveys recent and upcoming missions pursued by a variety of academic and government groups around the world.

Coning Control of Solar Sails Using Magnetic Momentum Error Reduction

achieved with zero control torque, enabling asymptotic stabilization of these equilibria in the local-vertical–localhorizontal frame despite the underactuation inherent in magnetic control. Lyapunov stability properties of these equilibria are determined under specific types of magnetic control, including a new angular momentum error reduction control law. Performance of a 3 kg CubeSat class microsailcraft is examined under magnetic coning control, showing that reliable convergence to equilibria in local-vertical–local-horizontal occurs, even in some naturally unstable cases, but that magnetic stabilization of other unstable equilibria is tenuous.

3326 コントロール・モーメント・ジャイロを用いた小型衛星の高速姿勢制御(S86-1 小型宇宙システム(1),S86 小型宇宙システム)

This paper investigates the feasibility of using control moment gyros (CMGs) as the actuator for agile attitude maneuvers of a small satellite. A prototype of miniature sized single-gimbal control moment gyro (SGCMG) has been developed in the laboratory. A cluster of four prototype SGCMGs has been investigated by numerical simulations for full-three-axes attitude control of a CUBESAT class micro-satellite.