Spacecraft Solar Panels Research Articles

A Hybrid Formulation for Modelling Multibody Spacecraft

In order to simulate the behavior of a space multibody system, the paper shows the possibility of shifting from a Newton Euler (NE) multibody approach to Lagrange Euler (LE) like formulation of equations of motion. The NE is convenient to understand and to write down the mechanics equations of the system, but the EL based equations of motion show a minimal mathematical complexity and a minimum number of equations in a minimum number of variables. The proposed procedure also allows to swiftly turn back to the NE formulation to calculate the reaction forces and torques among the bodies. The overall revised hybrid formulation, built by mixing both NE and EL approaches, is applied for simulating the deploying phase of spacecraft solar panels.

Efficient Silicon Solar Cells for Space and Ground-Based Aircraft

On the MCA “AIST 2” is planned the conduction of the experiment on the study of the outer space effects on the characteristics of experimental silicon photovoltaic cells (PVC)manufactured according to the technology developed in the Samara state University. Effective photovoltaic cells as sources of energy for aircraft are of great interest from developers of space technology, as for most of spacecraft solar panels are virtually non-alternative source of energy. Most high performance to date have nanoheterostructure PVC-based materials АIIIBV. However, despite the fact that silicon solar cells inferior to them on such an important parameter as efficiency, silicon continues to be the main material of the photo power engineering. This is due to the prevalence of raw materials and advanced technology of manufacture of the material and devices on its basis, providing a significantly lower cost silicon solar cells in comparison with analogues on the basis of materials АIIIBV. Therefore, the actual problem silicon solar cells is to increase their efficiency. Experimentally proved that silicon solar cells are not inferior in efficiency of energy conversion nanoheterostructures can be created on the basis of multilayer structures on single crystal silicon substrate in which there are materials with different band gap making it possible to reduce the fundamental losses in the crystal associated with nepogashenie photons with energy smaller than U (the width of the forbidden zone) of the crystal, and the thermalization of the crystal lattice in the absorption of photons with energy greater than Ed. Due to this, you can greatly exceed the theoretical limit of photovoltaic energy conversion to mono-silicon 27% [1].

Stardust Interstellar Preliminary Examination V:XRFanalyses of interstellar dust candidates atESRF ID13

AbstractHere, we report analyses by synchrotron X‐ray fluorescence microscopy of the elemental composition of eight candidate impact features extracted from the Stardust Interstellar Dust Collector (SIDC). Six of the features were unambiguous tracks, and two were crater‐like features. Five of the tracks are so‐called “midnight” tracks—that is, they had trajectories consistent with an origin either in the interstellar dust stream or as secondaries from impacts on the Sample Return Capsule (SRC). In a companion paper reporting synchrotron X‐ray diffraction analyses ofISPEcandidates, we show that two of these particles contain natural crystalline materials: the terminal particle of track 30 contains olivine and spinel, and the terminal particle of track 34 contains olivine. Here, we show that the terminal particle of track 30, Orion, shows elemental abundances, normalized to Fe, that are close toCIvalues, and a complex, fine‐grained structure. The terminal particle of track 34, Hylabrook, shows abundances that deviate strongly fromCI, but shows little fine structure and is nearly homogenous. The terminal particles of other midnight tracks, 29 and 37, had heavy element abundances below detection threshold. A third, track 28, showed a composition inconsistent with an extraterrestrial origin, but also inconsistent with known spacecraft materials. A sixth track, with a trajectory consistent with secondary ejecta from an impact on one of the spacecraft solar panels, contains abundant Ce and Zn. This is consistent with the known composition of the glass covering the solar panel. Neither crater‐like feature is likely to be associated with extraterrestrial materials. We also analyzed blank aerogel samples to characterize background and variability between aerogel tiles. We found significant differences in contamination levels and compositions, emphasizing the need for local background subtraction for accurate quantification.

Changes in K-208 glass transmittance spectra under ionizing radiation and molecular fluxes

The effect of 40-keV electron and proton radiation with a flux density of 5 × 10 cm−2 s−1 on the deposition of products of thermostimulated gas release from a polymer composite on a substrate made from protective K-208 glass used for the protection of spacecraft solar panels is experimentally investigated. Analysis of the obtained results shows that, unlike proton radiation, electron radiation results in an increase in the optical density of the glass and stimulates the deposition of gas-release products. It is established that the majority of effects generated as a result of exposure of the substrate to electron radiation are neutralized by protons upon combined irradiation with electrons and protons.

An Overview of Spacecraft Charging Research in India: Spacecraft Plasma Interaction Experiments—SPIX-II

Arcing on spacecraft solar panels has been a major challenge since it was first observed in late 1970s. Scientists of leading scientific countries like USA, Japan, France, and others are working hard to understand various aspects of this charging–arcing phenomenon. Based upon the experimental simulation results, a few arc mitigation techniques have been developed. In 2003, the Indian Space Research Organization (ISRO) realized the necessity to develop an experimental setup for understanding the charging–arcing phenomenon on satellite’s solar panels when parked in lower earth orbit (LEO) in the Space Plasma Interaction Experiments (SPIX) facility. The SPIX facility was jointly developed as a collaborative research project between the ISRO and the Institute for Plasma Research. In 2010, an initiative was taken for the upgradation of the SPIX facility for testing both LEO and geosynchronous earth orbit (GEO) satellite’s solar panels by the following standard ISO 11221 experimental procedure and indigenously developed high-speed data acquisition and analysis system. Various types of solar panel coupons were tested in upgraded SPIX-II facility. Sample solar panel coupons used in the experiments can be categorized based on the types of solar cells and the configurations of solar cell that includes different interstring gaps and grouting. For LEO satellite coupons, depending upon the types of solar panel coupons, different bias voltages were applied and threshold voltage was determined. Threshold arc tests were done at different bias voltages and electron gun energies for GEO satellite’s coupons. Arc rates and threshold voltages were measured for each type of solar panel coupon, which determined their durability and reliability in harsh environmental conditions. Grouted solar panel coupons had higher threshold voltage in both LEO and GEO worst environmental conditions. Results showed good repeatability and reproducibility for both LEO and GEO experiments. To measure sustained arc conditions, experiments were performed with different string voltages and string currents in both LEO and GEO environmental conditions. It was experimentally validated that the probability of temporary sustained arc or permanently sustained arc increases on increasing either string voltage or string current. In addition, an attempt is also made to understand the role of plasma curing of solar panel coupons and its impact on arc mitigation for GEO environment like space conditions.

Stardust Interstellar Preliminary Examination XI: Identification and elemental analysis of impact craters on Al foils from the Stardust Interstellar Dust Collector

AbstractThe Stardust Interstellar Preliminary Examination team analyzed thirteen Al foils from the NASA Stardust interstellar collector tray in order to locate candidate interstellar dust (ISD) grain impacts. Scanning electron microscope (SEM) images reveal that the foils possess abundant impact crater and crater‐like features. Elemental analyses of the crater features, with Auger electron spectroscopy, SEM‐based energy dispersive X‐ray (EDX) spectroscopy, and scanning transmission electron microscope‐based EDX spectroscopy, demonstrate that the majority are either the result of impacting debris fragments from the spacecraft solar panels, or intrinsic defects in the foil. The elemental analyses also reveal that four craters contain residues of a definite extraterrestrial origin, either as interplanetary dust particles or ISD particles. These four craters are designated level 2 interstellar candidates, based on the crater shapes indicative of hypervelocity impacts and the residue compositions inconsistent with spacecraft debris.

Conceptual Design and Assessment of an Electrostatic Discharge and Flashover Detector on Spacecraft Solar Panels

This paper presents a concept of monitor aiming at measuring the electrostatic discharge (ESD) occurrence and, possibly, a flashover expansion on spacecraft photovoltaic solar panels. The passive measurement of solar cell cover glass surface potential is used as a diagnostic. The monitor consists of small metallic plates located on the sunlit solar panel. With a sufficient electrical insulation from the spacecraft structure, these plates float to the same potential as the surrounding cover glasses. The photoemission is the physical phenomenon allowing the homogenization of the local surface potentials. Theoretical, numerical, and experimental investigations are used to assess how well such a device could record the evolution of the solar panel surface voltage. Combined with a dedicated measurement chain and telemetry, ESD occurrences could thus be measured on in-flight solar panels.

Time-Resolved Spectroscopy of Electrostatic Discharge and Secondary Arc Plasma on Spacecraft Solar Array

Primary electrostatic discharges (ESD) and secondary arcs on spacecraft solar panels are simulated experimentally by introducing a needle trigger and investigated with a time-resolved emission spectroscopy method. The total spectral domain investigated ranges from 220 to 750 nm. An innovative active method has been developed in order to initiate ESD at a controllable time and location on triple-junction solar cells. It permits one to detect important steps of the discharge evolution, in particular the transition between primary ESDs and secondary arcs. In this experimental setup, the discharge begins on the triple-junction solar cell absorber, with gallium and germanium being detected from the very beginning. That indicates that the obtained ESDs are triggered on the solar cell edge close to the cover glass. The transition between primary ESDs and secondary arcs is accompanied by molecular material vaporization. It is thought that the glue or the underlying polyimide is evaporated mainly during secondary arcs, sometimes during primary ESDs. Once the secondary arcing is triggered, the complete edge of the solar cell assembly is impacted. That confirms that ESDs may significantly damage the solar cell assemblies.

Fuzzy Vibration Control of Flexible Solar Panel Using Piezoelectric Stack

To effectively suppress vibrations of the flexible solar panel, the fuzzy logic control with piezoelectric smart structure is studied. The bending moment induced in the solar panel by the PZT stack actuator is formulated. The dynamical equations of the solar panel are derived. A fuzzy logic controller which uses universal fuzzy sets is designed. Considered the characteristic of the PZT stack, only positive control voltages were loaded to it. The finite element method simulation results demonstrate that the fuzzy logic controller can suppress the vibrations of the flexible spacecraft solar panel effectively.

Optimal placement and decentralized robust vibration control for spacecraft smart solarpanel structures

The decentralized robust vibration control with collocated piezoelectric actuator andstrain sensor pairs is considered in this paper for spacecraft solar panel structures.Each actuator is driven individually by the output of the corresponding sensor sothat only local feedback control is implemented, with each actuator, sensor andcontroller operating independently. Firstly, an optimal placement method for thelocation of the collocated piezoelectric actuator and strain gauge sensor pairs isdeveloped based on the degree of observability and controllability indices forsolar panel structures. Secondly, a decentralized robust controller is designed to suppress the vibration induced by external disturbance. Finally, anumerical comparison between centralized and decentralized control systems is performedin order to investigate their effectiveness to suppress vibration of the smart solar panel. Thesimulation results show that the vibration can be significantly suppressed with permittedactuator voltages by the controllers. The decentralized control system almost has the samedisturbance attenuation level as the centralized control system with a bit higher controlvoltages. More importantly, the decentralized controller composed of four three-ordersystems is a better practical implementation than a high-order centralized controller is.

Discharge of Spacecraft Solar Panels by Hypervelocity Impact

Small particles of less than 0.5 mm diameter collide with spacecraft solar panels, which work as an electrical power supply. Sustained arc discharging does not occur during such impacts, although trigger discharges are generated during several hundreds of milliseconds. The electrical performance of the solar panels is degraded slightly, but not enough to affect satellite systems.

Thermal Force Modeling for Precise Prediction and Determination of Spacecraft Orbits

The physical modeling of nonconservative forces is a limiting factor in orbit prediction. One such force arises from the anisotropic emission of thermal radiation from a satellite's surface, which can perturb a spacecraft trajectory significantly. Hence a thermal analysis is crucial for precise analytical force modeling. This paper presents the authors' approach to thermal force modeling, using GPS Block IIR and the altimetry satellite Jason-1 as test cases. The treatment of spacecraft multilayer insulation, solar panels, and other spacecraft components is described. A novel approach to determining eclipse boundary crossing times for an oblate earth and the characterization of penumbral flux are discussed. The GPS Block IIR models are tested by incorporation into a high-precision radiation pressure model developed at University College London. Orbit predictions show significant improvements with inclusion of the thermal models. The Jason-1 models have been incorporated into the routine orbit determination of Jason-1 by the Jet Propulsion Laboratory.

Simulation of the Initial Deployment Kinetics of a Spacecraft Solar Array

This paper presents a mathematical simulation of the initial deployment kinetics of a spacecraft solar array panel stack and its primary deployment mechanism. Two methods for achieving initial deployment are considered. The first deployment method involves the motorized deployment of a single hinge. The second deployment method involves the spring actuated deployment of two hinges. In the motorized deployment case, the solar array is predicted to slide against the spacecraft sidewall before separation. In the spring actuated deployment case, the solar array is predicted to separate from the spacecraft sidewall without sliding.

Impingement Calculations for Ultra-Low Density Helium Thrusters

A new semi-empirical thruster plume model is presented based on recent experimental and numerical (Direct Simulation Monte Carlo) studies. The results are unique in that they pertain to unprecedentedly low flow rates (nozzle Reynolds numbers below 200). The model is used in computing the impingement forces acting on a spacecraft solar panel emersed in a thruster plume. The time-varying impingement effects due to changes in surface temperature were found not to be a serious limitation on the thruster calibration accuracies for the GP-B and STEP spacecraft. This suggests that both spacecraft could yield useful aeronomic data through monitoring of the thruster activity of the drag-free control systems.

Electrostatic rocket exhaust effects on solar- electric spacecraft subsystems

Electrostatic rocket exhaust condensation on spacecraft solar electric panels cover glasses, noting deleterious effects