REGULUS Electric Propulsion Module IoD in UniSat-7 Mission

T4i is a propulsion system company founded in 2014, originated from the Space Propulsion Group of University of Padua, Italy, and active in the market of small satellites. In the last decade T4i has been developing REGULUS, a cutting-edge electric propulsion system for in-space mobility fed with iodine propellant. REGULUS has been specifically designed for Cubesats and micro satellite platforms and it is based on a RF Magnetically Enhanced Plasma (MEP) thruster. Thanks to its standard interfaces it is conceived to be easily “plugged&played” into the satellite, without complex engineering procedures

UNISAT-7: A Flexible IOD Platform with Orbital Maneuvering Capabilities

New Space technology for Small Satellites has greatly advanced in the past five years. These progresses shall match with a swift integration and testing phase, to be readily marketable, therefore IOD missions are essential to expedite project outcomes. GAUSS has started working on Small Satellites since 1990s, with its first satellite, UNISAT, launched in 2000. In 2013, UNISAT-5 was the first platform to accomplish in-orbit-release of third-party satellites, with UNISAT-6 following in less than one year. UNISAT-7 is the latest addition to the UNISAT series: a 32kg microsatellite designed and manufactured by GAUSS Srl (a spin-off company of Scuola di Ingegneria Aerospaziale, Sapienza University of Roma), built from scratch thanks to the extensive experience gained with past missions. Launch is scheduled in in Q1 2021. It is the most complex mission ever flown by GAUSS, and it includes several original GAUSS subsystems developed for Earth Observation, sat-to-ground optical links, navigation, power, RF, and Smallsat in-orbit-deployments. All these subsystems are tested in orbit in specific IOD missions. Moreover, UNISAT-7 integrates a precise ADCS solution and a newly developed low-thrust, electric propulsion system named REGULUS, from Italian Company Technology for Propulsion and Innovation (T4i), which will allow the satellite to modify its final orbit, as well as to execute housekeeping maneuvers for drag compensation. REGULUS is a propulsive unit based on MEPT (Magnetically Enhanced Plasma Thruster) technology developed inside the propulsion laboratory of the University of Padua. T4i, born as a Spin-off of the University of Padua, industrialized this technology in order to make it fly. REGULUS is T4i very first product that has ever flown into space. Its envelope is 1.5 U of volume, it is equipped with solid iodine propellant and its main features are a thrust level of 0.55 mN and Isp of 550 s at 50 W of input power, and wet mass of 2.5 kg at 3000 Ns of Itot. REGULUS is designed to serve nanosatellite platforms from 6U to 24U and CubeSat carriers. The integration took place in GAUSS white chamber in Rome in late 2020 and the launch is scheduled in March 2021 from Baikonur as a secondary payload of Soyuz-2-1a/Fregat. Performances of REGULUS propulsion system are evaluated after the initial commissioning of UNISAT-7. This key IOD mission paves the way to next UNISAT programs, where GAUSS microsatellites will be able to execute orbital maneuvers before any single CubeSat deployment, in order to efficiently shape customized constellations by using UNISATs as autonomous vehicles for in-orbit-deployment. Provide an informative abstract of no more than 500 words. The abstract should stand alone as a summary of the paper, not as an introduction (i.e., no numerical references). Type the abstract across both columns and fully justified

REGULUS CubeSat Propulsion System: In-Orbit Operations

A robust, versatile, and cost-effective propulsion system to provide wide mobility to small satellite platforms and nanosatellite deployers. A Plug&Play propulsion system designed to be easily integrated into different satellite platforms and to match customer\u27s requirements, with minimal customization efforts and costs

REGULUS Iodine Electric Propulsion System Integration in CubeSats’ Platforms and Testing

REGULUS is an electric propulsion (EP) system for CubeSats at TRL8 and now waiting for the IoD flight in late 2020. REGULUS system is provided for integration with all electronics, fluidic line, iodine tank and structures for total mass below 3 kg. Thanks in particular to the Magnetically Enhanced RF Plasma Thruster (MEPT) technology and the use of iodine propellant, the system can provide 3000Ns of total impulse in a 93.8 x 95.0 x 150.0 mm volume performance, fitting in a 1.5U Cubesat. REGULUS includes the whole propulsion package for integration in CubeSats and MicroSats as well as small CubeSat carriers. The system is composed by the thruster, the electronics (PPUs and PCU) the fluidic line and the tank. The main features of REGULUS are the presence of a simple architecture, a thruster with no neutralizer and grids, no high DC-voltage PPU and the use of solid iodine as propellant, that can be substituted with Xenon fluidic line and tank when required. Its first mission will be onboard of Unisat-7 by GAUSS. The flight will take place in late 2020 in a Soyuz flight. During the mission, REGULUS will allow Unisat-7 to perform an orbit descending maneuver, drag compensation in VLEO and decommissioning

Validation of a new classification method of impacted maxillary canines on CBCT with assesment of apico-root resorption and implementation of KPG index

noneBackground: Sono già presenti in letteratura delle classificazioni di canini mascellari inclusi in CBCT, ma non vengono presi in considerazione congiuntamente il grado di riassorbimento apicale e l’indice KPG. Quest’ultimo inoltre valuta solo l’angolazione antero-posteriore, verticale e assiale, non considerando l’angolazione del canino in senso mesio-laterale. Il presente studio è volto ad implementare classificazioni di canini mascellari inclusi su CBCT già esistenti che non prendono in controllo il grado di riassorbimento apico-radicolare e indice KPG, associando inoltre angolazione del canino in senso mesio-laterale. Scopo dello studio: Lo scopo del presente studio è validare un nuovo metodo di classificazione dei canini mascellari inclusi CBCT valutando il rimaneggiamnto apicale e implementando l’indice KPG. Materiali e metodi: È stata effettuata una ricerca bibliografica utilizzando le principali banche dati quali Pubmed e Scopus per le classificazioni di canini mascellari inclusi già esistenti in CBCT. La ricerca è stata condotta utilizzando le seguenti parole chiave: “impacted maxillary canines”, “impacted canines opt” “impacted canines CBCT”, “classification impacted canines in CBCT”, “root resorption” “canine ankylosis”, “cone beam computed tomography”, “eruption cyst”, “dentigerous cyst”. L’intervallo temporale è stato fissato dal 1980 ad oggi. Gli articoli senza porre limite di lingua verranno selezionati in base all’analisi del contenuto dell’abstract e/o dell’articolo full text. Sperimentalmente con il seguente studio verranno screenate le CBCT e, in presenza di canini mascellari inclusi, verranno valutate sul piano sagittale, coronale e assiale: l’angolazione verticale, laterale vestibolo-palatale, mesio-distale e mesio-laterale (implementazione indice kpg). Verrà inoltre preso in controllo il grado di riassorbimento apico-radicolare degli elementi dentali adiacenti.Background: Many classifications of impacted maxillary canines on CBCT are present in literature, but they do not take into consideration root resorption and KPG index jointly. Moreover, the latter only considers the anterior-posterior, vertical and axial viewpoint, without taking into account the impacted canine perspective in the mesial-lateral perspective. The present study is aimed at implement the already existing classifications of impacted maxillary canines on CBCT that do not take control over the apico-root resorption and the KPG index, also associating the angular measurements of the canine in the mesial-lateral perspective. Objectives: The aim of the present study is to validate a new classification system of impacted maxillary canines on CBCT assessing the apex-root structural changes and the KPG index. Materials and methods: A bibliographical reserch was carried put using the main databases as Pubmed and Scopus for the already existing classifications of impacted maxillary canines on CBCT. The research was conducted using the following keywords: “impacted maxillary canines”, “impacted canines opt” “impacted canines CBCT”, “classification impacted canines in CBCT”, “root resorption” “canine ankylosis”, “cone beam computed tomography”, “eruption cyst”, “dentigerous cyst”. The time interval has been set from 1980 until today. The articles have been selected according to the abstract and/or the full text without setting limits on languages. Experimentally, the present study has screened the CBCT and, in the presence of impacted maxillary canines, the vertical, lateral, vestibular-palatal, mesial-distal and mesial-lateral positions has been assessed on the sagittal, coronal and axial planes. Moreover, location and severity of apical-root resorption of neighbouring teeth has been considered

“O/F shift” in hybrid rockets

For most hybrid rocket systems, oxidizer to fuel ratio (O/F) changes over time due to 1) natural growth of the fuel port diameter and 2) oxidizer flow rate variations, if throttling is employed. This phenomenon, which is referred to as “O/F shift”, leads to a reduction in motor performance. Note that liquid or solid rocket motors are not subject to temporal O/F variations, which is wrongfully considered as one of the most critical disadvantages of hybrid rockets. In this paper, the effect of “O/F shift” is quantified for hybrid rocket motors. Analytical formulas for the temporal O/F variation and the overall c* efficiency drop associated with the variation has been derived for single circular port motors. It has been shown that for a typical motor, c* efficiency drop due to O/F variation is well below 0.2%, a value which is too small to be measured in an actual motor test. It is also shown that for a wagon wheel type multiport configuration (with triangular ports), efficiency drop is significantly worse than the single circular port case. Even for the multiport systems, the shift does not have a controlling effect on the overall efficiency of the motor. A number of strategies have been outlined to control the adverse effects of O/F variation in a hybrid rocket. For a single circular port design with limited throttling, no mitigation is required. For systems with deep throttling requirements, aft oxidizer injection seems like a viable strategy to retain a high level of overall efficiency

Paraffin-Based Fuel for Hybrid Rocket Engines Application Feasibility Studies

This paper describes combined analysis performed in pure waxes and paraffin based mixtures that can be used as fuels in hybrid engines. The feasibility of the use of such materials as fuels in hybrid rockets is under study at SPLab in Politecnico di Milano and at the DLR Institute of Space Propulsion in Germany. Density measurements of pure waxes were performed using a dilatometer. An experimental facility was set up and, after preliminary measurements and calibration, a repeatable procedure was implemented. The implemented instrumentation set up allowed the measure of density in softening and melting intervals. Mechanical uniaxial tensile tests were performed according to Standard ISO 527-1, on pure macro paraffin and microcrystalline wax and on these waxes doped with stearic acid and graphite; elastic modulus, elongation and maximum stress were calculated. Data indicates that ductile rupture is achievable even on pure tested macro paraffin. Moreover micro-crystalline wax was mixed with a synthetic wax characterized by higher nominal melting temperature in order to improve the softening point up to higher temperatures without compromising regression rate values. Thermal, rheological, viscosimetric and ballistic experiments were performed on this new formulation, promising for applications characterized by wide temperature ranges