Acta Astronautica最新文献

{"title":"Influence of flame collisions with pressure waves on tulip flame formation and its evolution in tubes with non-slip walls","authors":"Chengeng Qian ,&nbsp;Mikhail A. Liberman","doi":"10.1016/j.actaastro.2025.03.001","DOIUrl":"10.1016/j.actaastro.2025.03.001","url":null,"abstract":"<div><div>The effects of flame collision with pressure waves during hydrogen/air flame propagation in a two-dimensional channel with non-slip adiabatic walls are studied for channels with different aspect ratios and a semi-open channel. The problem is solved by direct numerical simulations of the fully compressible Navier-Stokes equations coupled to a detailed chemical model for a stoichiometric hydrogen-air mixture using a high-order numerical code in space and time that provides adequate resolution of a flame and the flame-pressure wave interactions. It is shown that the flame–pressure wave interactions play an important role in the tulip flame formation and its further evolution to a distorted tulip flame (DTF). In particular, flame collisions with pressure waves reflected from the opposite end of the tube significantly enhance the effect of the first rarefaction wave generated by the decelerating flame in the unburned gas when the skirt of the “finger” flame touches the tube sidewalls. This is why the tulip-shaped flame is more pronounced in channels with both ends closed than in a semi-open tube. It is shown that the flame instabilities are not involved in the tulip flame formation, while the Rayleigh-Taylor instability caused by the flame collisions with the reflected pressure waves is the main factor in the DTF formation, in agreement with previous studies. We show that the wavelength of the fastest growing mode of the RT instability corresponds to the size of the bulges formed on the tulip flame lips.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 154-163"},"PeriodicalIF":3.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Italian Spring Accelerometer measurements of unexpected Non Gravitational Perturbation during BepiColombo second Venus swing-by","authors":"Carmelo Magnafico,&nbsp;Umberto De Filippis,&nbsp;Francesco Santoli,&nbsp;Carlo Lefevre,&nbsp;Marco Lucente,&nbsp;David Lucchesi,&nbsp;Emiliano Fiorenza,&nbsp;Roberto Peron,&nbsp;Valerio Iafolla","doi":"10.1016/j.actaastro.2025.02.037","DOIUrl":"10.1016/j.actaastro.2025.02.037","url":null,"abstract":"<div><div>The Italian Spring Accelerometer (ISA) is a three axis mass–spring accelerometer, one of the payloads of the BepiColombo joint space mission between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA). At launch in October 2018, BepiColombo started its seven-year cruise as a stack of three different modules, overall named Mercury Composite Spacecraft (MCS). The spacecraft will provide BepiColombo the necessary Delta V to reach Mercury with its electric thrusters and along with one, two and six gravity assists, respectively with Earth, Venus and Mercury. The accelerometer is accommodated on the Mercury Planetary Orbiter (MPO) module and, jointly with the Ka-band Transponder (KaT) tracking data, will primarily serve the BepiColombo Radio Science Experiment (BC-RSE). During the second Venus swing-by, strong tidal effect and external perturbations was expected to act on the spacecraft and to become detectable by ISA. The swing-by had a closest approach of about 550 km and the gravity gradient on the IDA sensing elements was measured as expected. Hence, in this paper, the first direct gravity gradients effect detection generated by an extraterrestrial body is shown. Nevertheless, around the closest approach, the measurements evidenced a spurious acceleration event lasting for several minutes. This work, exploiting information on the Attitude and Orbit Control System (AOCS) commanded torques, focuses and analyses this ISA acceleration signal, ascribing it to a net force really acting on the MCS spacecraft. Furthermore, using an estimation method, the application point of the force is identified within an area close to the MPO radiator.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 14-22"},"PeriodicalIF":3.1,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomization of gel propellants using a Hartmann whistle injector","authors":"Dingwei Zhang ,&nbsp;Boqi Jia ,&nbsp;Yue Zhang ,&nbsp;Hu Sun ,&nbsp;Qiyou Liu ,&nbsp;Bingqiang Ji ,&nbsp;Lijun Yang ,&nbsp;Qingfei Fu","doi":"10.1016/j.actaastro.2025.02.049","DOIUrl":"10.1016/j.actaastro.2025.02.049","url":null,"abstract":"<div><div>Gel propellants, which combine the benefits of solid and liquid propellants, suffer from poor atomization quality due to their high viscosity. Sonic atomization technology has demonstrated potential in atomizing high-viscosity non-Newtonian fluids. This study designed a Hartmann whistle injector comprising a central gas path, an annular slit liquid path, and a resonant cavity. Schlieren imaging and the microphone measurements revealed that the sound waves originate at the leading edge of the resonant cavity, with an optimal gas path pressure identified for generating the strongest acoustic field. A water-based simulant with rheological properties similar to gel propellants was employed for atomization experiments. High-speed imaging demonstrated that the Hartmann whistle injector significantly enhanced gel liquid breakup, reducing the Sauter Mean Diameter (SMD) by up to 37 % compared to the conventional gas-liquid coaxial injector. Orthogonal experiments investigated the effects of liquid annular slit width, central rod diameter, resonant cavity distance, and gas pressure on atomization performance, revealing optimal parameter combinations. These findings highlight the potential of Hartmann whistle injectors for advancing gel propulsion technologies.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 39-50"},"PeriodicalIF":3.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heaterless LaB6 lollipop hollow cathode for center-mounting in Hall thrusters","authors":"Dan M. Goebel ,&nbsp;Adele R. Payman ,&nbsp;Giulia Becatti ,&nbsp;Jacob Simmonds","doi":"10.1016/j.actaastro.2025.02.045","DOIUrl":"10.1016/j.actaastro.2025.02.045","url":null,"abstract":"<div><div>Hollow cathodes are a critical component of Hall thrusters, providing electrons for both plasma generation and beam neutralization. A new 10-kW-class thruster, named the H10, has been developed at JPL and demonstrated &gt;3000 s Isp and over 70 % efficiency in steady state operation at up to 15 kW. The cathode for the H10 thruster is a heaterless lanthanum hexaboride (LaB₆) hollow cathode designed in a “lollipop” configuration and center-mounted in the Hall thruster. This shape features a short, compact cathode body that contains the LaB₆ thermionic insert, graphite keeper and alumina insulators. The cathode assembly then necks down to a small diameter gas feed tube that acts as the cathode electrical conductor, and a separately insulated keeper lead. This geometry is ideally suited for magnetically shielded Hall thrusters because it minimizes the amount of magnetic material that must be removed from the inner magnetic core to fit in the centrally-mounted cathode, thus enabling higher magnetic fields by reducing saturation of the inner core. The heaterless cathode starts in only 3 min using less than 100 W of keeper discharge power, and has demonstrated operation in the thruster at discharge currents of 2–50 A. The design, performance and life of the cathode and heater are described.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 193-199"},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Properties of novel LX lunar regolith simulant system — The base simulants: Part 1","authors":"Joel Patzwald ,&nbsp;Rafael Kleba-Ehrhardt ,&nbsp;Ferry Schiperski ,&nbsp;Tjorben Griemsmann ,&nbsp;Stefan Linke ,&nbsp;Thomas Neumann ,&nbsp;Ludger Overmeyer ,&nbsp;Enrico Stoll ,&nbsp;David Karl","doi":"10.1016/j.actaastro.2025.02.030","DOIUrl":"10.1016/j.actaastro.2025.02.030","url":null,"abstract":"<div><div>The renewed interest in lunar exploration has increased research efforts in lunar in-situ resource utilisation (ISRU), which involves using locally sourced materials to reduce reliance on expensive and complex Earth-based logistics. Lunar regolith, a loose layer of fragmented rock covering the Moon’s surface, often many metres thick, is the primary ISRU material due to its abundance and accessibility. It can, for example, be used to construct infrastructure, extract consumables, and produce secondary goods. Lunar regolith analogue materials (simulants) are fundamental for developing and testing such ISRU technologies in laboratories on Earth before they are applied to other celestial bodies. The composition of the regolith on the lunar surface varies greatly in terms of its mineralogical, chemical, and particle type composition. Current simulants fail to adequately replicate this variability. Therefore this study introduces a flexible simulant system capable of tailoring simulants to different applications. The lithic base simulants LX-T100 (anorthosite) and LX-M100 (basalt) represent the Moon’s two major bedrock types and serve as the foundation for this system. In this study, these base simulants are comprehensively characterised in terms of their mineralogy using XRD, chemistry using XRF, particle size distribution by dry and wet sieving, laser scattering, and dynamic image analysis, particle morphology via image analyses, maximum, minimum, bulk, and solid density using a tapped volumeter, Scott volumeter, bulk density funnel, and pycnometer, respectively, and from these the void ratio and porosity are calculated. It is shown that the base simulants are good analogue materials for lunar soil. In Europe, in particular, the LX simulants aim to address the poor availability of suitable simulants.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 200-222"},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LEIA: NASA's first biological mission on the lunar surface since 1972","authors":"Alina Lambacher ,&nbsp;Kylie Akiyama ,&nbsp;Neha Lingam ,&nbsp;Dunya Shuman ,&nbsp;Sergio R. Santa Maria","doi":"10.1016/j.actaastro.2025.02.050","DOIUrl":"10.1016/j.actaastro.2025.02.050","url":null,"abstract":"<div><div>The Lunar Explorer Instrument for space biology Applications (LEIA) mission was awarded in 2022 by NASA. LEIA will be delivered to the lunar surface no earlier than 2027 on a commercial lunar lander. It aims to investigate the effects of the lunar surface environment on biological organisms. Particularly, LEIA will study the effects on different DNA damage and stress response mechanisms, as well as on synthetic bioproduction of antioxidants in the budding yeast <em>Saccharomyces cerevisiae</em>. To achieve these aims, LEIA consists of a science suite of three instruments: a microfluidic-based system (BioSensor) with microbial growth support capabilities, a charged particle detector (LET spectrometer), and a mini fast neutron detector (mini-FND). The BioSensor instrument has high heritage from NASA's BioSentinel CubeSat mission, which launched to a heliocentric orbit onboard the Artemis I rocket in late 2022 (currently at 60 million kms from the Earth). An identical BioSensor payload successfully performed biological experiments on the International Space Station (ISS) in 2021–2022. The BioSensor instrument contains a complex fluidic system that delivers nutrients to desiccated yeast cells in fluidic cards. Growth and metabolic activity are monitored via optical absorbance measurements, thus allowing for the detection of changes caused by cellular or DNA damage on the lunar surface. In addition, it allows to measure and detect the effects on the bioproduction of dietary antioxidants. The LET spectrometer and mini-FND instruments will quantify and characterize the lunar surface radiation environment. Thus, LEIA will support the development of potential countermeasures for future human missions to the Moon. In addition to using high-heritage instrumentation, many lessons learned from BioSentinel have been implemented in the design and development of LEIA.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 148-152"},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Fifth Volta Congress, Rome 1935. The birth of supersonic aerodynamics","authors":"Mario Marchetti","doi":"10.1016/j.actaastro.2025.02.039","DOIUrl":"10.1016/j.actaastro.2025.02.039","url":null,"abstract":"<div><div>The Fifth Volta Congress, the first International Congress on High Speeds in Aeronautics, organized by the Royal Academy of Italy and AIDA, the Italian Association of Aerotechnics, was held in Rome in 1935. The topic was chosen in response to the specific needs of a time when the main interest of the various countries was to have high-speed aircraft at their disposal to increase the prestige of each nation. The research carried out in the 1930s had not as yet reached a sufficient scientific level to clear up the many issues regarding high-speed flight. The nature of the physical transformations brought about by fluid compressibility at high speeds and their effects within the well-known laws of aerodynamics and the point at which they are no longer negligible were still not clear.</div><div>Italy was keen to enhance its aeronautical development, and the Fascist regime under Benito Mussolini was well aware of the fact. Mussolini’s intention was to consolidate his power yet further, and together with Adolf Hitler, he created the Rome-Berlin Axis in the field of aeronautical technology, Achse Berlin-Rom - auch in der Luftfahrttechnik.</div><div>Under this agreement, two eminent Italian scientists, Gaetano Arturo Crocco, Dean of the School of Aeronautical Engineering of Rome, President of AIDA, the Italian Association of Aerotechnics, and Guglielmo Marconi, Nobel Prize in Physics in 1909, President of the Royal Academy of Italy and of the CNR, National Research Council of Italy, decided to organize a special event: “The Fifth Volta Congress”, dedicated exclusively to the study of high-speed aerodynamics.</div><div>Attendance was by invitation only, and the greatest international experts on subsonic and supersonic aerodynamics took part, Theodore von Kàrmàn, Ludwig Prandtl, Adolf Busemann, Eastman N. Jacobs, Jakob Ackeret, Wladimir Margoulis, Geoffrey Ingram Taylor, Eugen Sänger and others.</div><div>The Congress saw the presence of many Italian scientists from universities and research centres, among which the DSSE, the Air Force Ministry’s High Directorate for Studies and Tests located in Guidonia near Rome and equipped with specific subsonic and transonic wind tunnels.</div><div>The Fifth Volta Congress was the event that laid the foundations for supersonic aerodynamics, thus opening up once and for all the Age of Astronautics.</div><div>As well as describing the scientific and political aspects of the Congress, the aim of the present work is also to analyze its influence on the development of supersonic and hypersonic aerodynamics which was then further accentuated with the research of Antonio Ferri and Luigi Broglio, the father of Italian Space.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 235-245"},"PeriodicalIF":3.1,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A design methodology for flat slab lunar landing and launch pad systems","authors":"Ian E. Jehn ,&nbsp;Christopher B. Dreyer","doi":"10.1016/j.actaastro.2025.02.046","DOIUrl":"10.1016/j.actaastro.2025.02.046","url":null,"abstract":"<div><div>This work applies established civil, structural, and geotechnical engineering design practices to a flat slab Landing and Launch Pad (LLP) or Vertical Takeoff Vertical Landing (VTVL) pad systems constructed on the lunar surface. While terrestrial launch and landing facilities exist as a potential starting point for understanding the analysis and design of these lunar pad systems, a design method has yet to be established within the space and lunar surface construction industry. The Basis of Design and analysis method outlined in this document are the result of feasibility and design studies conducted by the authors for LLP design and construction. It is meant to establish a baseline approach conducted by a licensed structural engineer with the ability and competency to design similar systems terrestrially. This work also identifies areas of knowledge gaps conducted in an effort to inform the industry of areas where future work can be conducted.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 175-192"},"PeriodicalIF":3.1,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of exercise intervention on executive function in 90-day head-down bed rest","authors":"Yaping Wang ,&nbsp;Zewei Li ,&nbsp;Rui Su ,&nbsp;Xieshun Wang ,&nbsp;Shihuan Gao ,&nbsp;Yining Wang ,&nbsp;Youran Zhang ,&nbsp;Yanjie Su","doi":"10.1016/j.actaastro.2025.02.033","DOIUrl":"10.1016/j.actaastro.2025.02.033","url":null,"abstract":"<div><div>Exercise is commonly used as an intervention strategy to enhance individual executive function. However, its effectiveness in improving executive function under prolonged head-down bed rest (HDBR) conditions remains unclear. The objective of this research is to examine whether physical exercise can improve executive function under HDBR conditions. We conducted a 135-day HDBR study involving 36 participants randomly allocated to five groups: control group (C), aerobic exercise combined with low-intensity resistance training (E1), aerobic exercise combined with high-intensity resistance training (E2), aerobic exercise alone (E3), and resistance training alone (E4). These exercise interventions were conducted during HDBR conditions. Additionally, we assessed working memory and cognitive flexibility throughout the study, including baseline (-3d), three intervention period assessments (30d, 60d, 90d), and a post-assessment (+30d). Findings revealed that during the early stage (30d) of HDBR, the intervention combining higher intensity resistance and aerobic exercises (E2) significantly enhanced cognitive flexibility. Conversely, in the mid-stage (60d) of HDBR, resistance training alone (E4) demonstrated superior improvement in cognitive flexibility compared to other intervention modalities. In conclusion, this study provides experimental evidence on the alterations in individual executive function under simulated long-term weightlessness conditions and offers guidance on the implementation of exercise interventions at various stages of HDBR conditions.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"232 ","pages":"Pages 23-31"},"PeriodicalIF":3.1,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sintering of Lunar regolith: A review","authors":"Sk S. Hossain ,&nbsp;Jeffrey W. Bullard","doi":"10.1016/j.actaastro.2025.02.038","DOIUrl":"10.1016/j.actaastro.2025.02.038","url":null,"abstract":"<div><div>The prospect of sustainable Lunar construction has received significant attention in recent years, driven by ambitions for Moon exploration and colonization. Among the various techniques explored, regolith sintering has emerged as a promising method due to its potential to efficiently utilize local resources like Lunar regolith and solar energy. Significant research has been conducted in recent years to advance regolith sintering through various innovative approaches using both mare and highland Lunar regolith simulants. This review presents a comprehensive overview of recent advances and obstacles in regolith sintering for Lunar construction. We focus on state-of-the-art regolith sintering techniques and their key parameters, highlighting their potential to design shapes with uniform density and microstructure. In addition, we review how the particle size distribution and mineralogical composition of the regolith simulants affect the physical and mechanical properties of the sintered shapes. Densification and key aspects of 3D printed regolith shapes are also discussed. Moreover, we evaluate the opportunities and current limitations for the further development of regolith sintering in Lunar construction. The review provides a perspective on in-situ resource utilization for Lunar construction through sintering technology, paving the way for future Lunar settlements.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 153-174"},"PeriodicalIF":3.1,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}