Article
Optics
Yang Ou, Jianjun Wu, Yu Zhang
Summary: The study investigates the use of carbon, graphite, and graphene as dopants to improve the performance of a laser-electric hybrid acceleration thruster. The results demonstrate that these dopants lead to higher impulse bit, specific impulse, discharge success rate, efficiency, and momentum coupling coefficient. Graphene shows the best doping effect, and the propellant sample made of 5% graphene and 95% poly-tetrafluoroethylene exhibits the best performance.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Daniele Palla, Gabriele Cristoforetti
Summary: This paper revisits the laser-accelerated plasma-propulsion system (LAPPS) for spacecraft, highlighting the impressive specific impulse achievable at different laser intensities. Using Walter's parameterization, specific impulse values and thrust-power ratios are discussed. The potential for increased engine thrust at fixed laser energy is also emphasized.
APPLIED SCIENCES-BASEL
(2021)
Review
Optics
Mingxia Xu, Baoan Liu, Lisong Zhang, Hongkai Ren, Qingtian Gu, Xun Sun, Shenglai Wang, Xinguang Xu
Summary: This review introduces the progress in the growth of large-aperture DKDP crystals and various aspects of crystal quality, including determination of deuterium content, distribution of deuterium, residual strains, nonlinear absorption, and laser-induced damage resistance. Large-aperture high-quality DKDP crystal with 70% deuteration level has been successfully grown using traditional methods. Neutron diffraction technique is an effective method for studying deuterium content and residual strains in single crystals. Efforts have been made in improving processes such as purity of raw materials, continuous filtration technology, thermal annealing, and laser conditioning to increase the laser-induced damage threshold (LIDT) of the crystals. These advancements support the development of the laser system for inertial confinement fusion (ICE) in China.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Energy & Fuels
Alberto Boretti
Summary: Hydrogen may replace traditional hydrocarbon fuels in propeller and jet aircraft. Combustion engines are preferred over fuel cells plus electric motors for propeller propulsion. Fuel cells have better appeal for novel urban air mobility solutions.
FRONTIERS IN ENERGY RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Gabriel R. Jaffe, Gregory R. Holdman, Min Seok Jang, Demeng Feng, Mikhail A. Kats, Victor Watson Brar
Summary: Laser sails powered by ground-based lasers could achieve relativistic speeds, allowing for fast interstellar travel. However, interplanetary dust poses a significant threat to the survival of laser sails during acceleration. Simulations demonstrate that a single dust particle can trigger a thermal runaway process, destroying the entire sail. Proposed mitigation strategies include increasing thermal conductivity and isolating absorptive regions of the sail.
Article
Engineering, Mechanical
Prasert Prapamonthon, Bo Yin, Guowei Yang, Mohan Zhang, Panpan Lu
Summary: The flexibility of wings plays a crucial role in improving the aerodynamic design, performance, and agility of aircraft. Research has shown that flexibility in wings can lead to thrust and lift redistributions, enhancing the overall aerodynamic performance of aircraft.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2021)
Review
Materials Science, Multidisciplinary
Yue Dong, Lu Wang, Veronica Iacovacci, Xiaopu Wang, Li Zhang, Bradley J. Nelson
Summary: This article summarizes the latest developments of helical micro-/nanomachines inspired by bacterial flagella for biomedical applications, focusing on their functionalization and key breakthroughs. The main challenges and future research directions are also discussed to further advance these tiny corkscrew-like machines towards translational medicine and minimally invasive interventions.
Article
Energy & Fuels
Xiaozhang Wang, Qunming Zhang
Summary: Laser direct writing technique proves its potential in producing high-performance microsupercapacitors through beam scanning, processing and patterning active substance simultaneously to form electrode features with high spatial resolution and accuracy. This method can construct 3D porous graphene, hierarchical porous frames, and nanostructures with precisely controlled porosity, facilitating the absorption, penetration, and transport of electrolyte ions for increased electrochemical performance in energy storage applications.
JOURNAL OF ENERGY STORAGE
(2021)
Article
Engineering, Aerospace
Young K. Bae
Summary: This paper presents optomechanical and quantum electronical analyses of a photonic laser thruster (PLT) using macroscale optical resonators to achieve spacecraft velocities on the order of 100 km/s. The study reveals key results such as the maximum achievable spacecraft velocity, power loss factors, and efficiency of laser energy conversion. The results validate the theoretical feasibility of enabling unprecedentedly fast interplanetary transportation systems with PLT technology.
JOURNAL OF PROPULSION AND POWER
(2022)
Article
Thermodynamics
Guillem Moreno Bravo, Nurgeldy Praliyev, Arpad Veress
Summary: The aircraft industry is still in the early stages of developing pure electric propulsion and hybrid systems, with a focus on battery weight and aerodynamic efficiency. Interest in distributed propulsion systems is also increasing. The research results provide important references for the future development of aircraft propulsion systems.
Article
Engineering, Aerospace
Nabil Souhair, Mirko Magarotto, Raoul Andriulli, Fabrizio Ponti
Summary: Atmosphere-breathing electric propulsion (ABEP) is an early-stage technology that uses the atmosphere as a propellant source for spacecraft, offering a clean and efficient propulsion system for very low Earth orbit (VLEO) missions. To optimize ABEP, accurate simulation of air-based plasma chemistry is crucial. This paper presents a global model that includes a detailed chemistry model for ABEP applications, aiming to forecast the performance of a cathode-less RF plasma thruster under different pressure levels and species concentrations typical of VLEO missions. The numerical model shows promise for ABEP system design and mission optimization.
Article
Engineering, Aerospace
Yang Ou, Jianjun Wu, Yu Zhang, Jian Li
Summary: This study developed an accurate predictive simulation model that captures materials moving front, updates the internal heat source, and characterizes the non-Fourier effect in laser-polymer interactions. The mathematical model was numerically implemented using a two-dimensional finite volume method and considered progressive surface removal, thermal decomposition, and non-Fourier effect. The simulations for laser ablation of polyoxymethylene with a carbon dioxide laser under different parameters showed good agreement with experimental results.
Article
Mechanics
Abdallah Daddi-Moussa-Ider, Babak Nasouri, Andrej Vilfan, Ramin Golestanian
Summary: The study reveals that the optimal propulsion strategy of microswimmers depends on their shape profile, which could be puller, pusher or neutral. Among all the modes of the shape function, only the third mode determines the swimming type of the optimal swimmer at leading order.
JOURNAL OF FLUID MECHANICS
(2021)
Review
Chemistry, Multidisciplinary
Wenjun Chen, Hao Zhou, Bin Zhang, Qinghua Cao, Bo Wang, Xing Ma
Summary: This article reviews the design, fabrication technologies, and actuation mechanisms of cell-transport microrobots, and discusses their applications, challenges, and future prospects.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Albert Cisquella-Serra, Marc Galobardes-Esteban, Manuel Gamero-Castano
Summary: This article introduces a microfabrication technique for creating scalable multiemitter electrospray sources and demonstrates their excellent propulsive performance through testing. Design elements such as a network of microfluidic channels, accurate alignment, and a pipe-flow configuration contribute to the improved performance and protection of propellant.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Astronomy & Astrophysics
Vishal Gajjar, Karen Perez, Andrew P. Siemion, Griffin Foster, Bryan Brzycki, Shami Chatterjee, Yuhong Chen, James M. Cordes, Steve Croft, Daniel Czech, David DeBoer, Julia DeMarines, Jamie Drew, Michael Gowanlock, Howard Isaacson, Brian C. Lacki, Matt Lebofsky, David H. E. MacMahon, Ian S. Morrison, Cherry Ng, Imke de Pater, Danny C. Price, Sofia Z. Sheikh, Akshay Suresh, Claire Webb, S. Pete Worden
Summary: In this study, deep observations were conducted towards the Galactic Center to search for potential extraterrestrial intelligence. Preliminary results revealed constraints on ETI transmitters and artificially dispersed transient signals, as well as the presence of Fast Radio Burst-like magnetars in the region. However, no new transient bursts were detected, suggesting limits on the presence of radio-loud magnetars at the Galactic Center.
ASTRONOMICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Raffy Traas, Steve Croft, Vishal Gajjar, Howard Isaacson, Matt Lebofsky, David H. E. MacMahon, Karen Perez, Danny C. Price, Sofia Sheikh, Andrew P. Siemion, Shane Smith, Jamie Drew, S. Pete Worden
Summary: Research focuses on exoplanetary systems as prime targets for the Search for Extraterrestrial Intelligence, with recent missions like TESS confirming the commonality of Earth-like planets. This study uses modified turboSETI pipeline architecture to search for narrowband signals from 1 to 11 GHz from potential exoplanet host stars identified by TESS, determining that only a small percentage have transmitters operating at these frequencies.
ASTRONOMICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Daniel Czech, Howard Isaacson, Logan Pearce, Tyler Cox, Sofia Z. Sheikh, Bryan Brzycki, Sarah Buchner, Steve Croft, David DeBoer, Julia DeMarines, Jamie Drew, Vishal Gajjar, Brian C. Lacki, Matt Lebofsky, David H. E. MacMahon, Cherry Ng, Imke de Pater, Danny C. Price, Andrew P. V. Siemion, Ruby Van Rooyen, S. Pete Worden
Summary: New radio telescope arrays provide unique opportunities for large-scale commensal SETI surveys, with Ethernet-based architectures allowing multiple users to access data simultaneously. Breakthrough Listen will conduct a commensal SETI survey on the MeerKAT radio telescope in South Africa, using raw voltage data streams to observe millions of objects with unprecedented speed.
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
(2021)
Article
Astronomy & Astrophysics
Noah Franz, Steve Croft, Andrew P. Siemion, Raffy Traas, Bryan Brzycki, Vishal Gajjar, Howard Isaacson, Matthew Lebofsky, David H. E. MacMahon, Danny C. Price, Sofia Z. Sheikh, Julia DeMarines, Jamie Drew, S. Pete Worden
Summary: In this study, a thorough radio technosignature search was conducted on 61 TESS Targets of Interest (TOIs), but no interesting technosignals were detected. The results indicate that only a small portion of these targets have high radiated power.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Brian C. Lacki, Bryan Brzycki, Steve Croft, Daniel Czech, David DeBoer, Julia DeMarines, Vishal Gajjar, Howard Isaacson, Matt Lebofsky, David H. E. MacMahon, Danny C. Price, Sofia Z. Sheikh, Andrew P. Siemion, Jamie Drew, S. Pete Worden
Summary: This article introduces Breakthrough Listen's Exotica Catalog, aiming to expand the diversity of targets surveyed in SETI. The concept of survey breadth and reasons for pursuing a broad program are discussed. The Exotica Catalog contains different samples like Prototype, Superlative, Anomaly, and Control, representing various aspects of astrophysics.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2021)
Article
Engineering, Aerospace
Petr Bohacek, Simon P. Worden, Kyran Grattan
Summary: Despite national space mining legislations, there is legal ambiguity in Space Resource Utilization (SRU) that increases investment risks. The vagueness of benefit-sharing requirements from space activities under the Outer Space Treaty Article I is identified as the main legal gap in SRU. To address the legal uncertainty and attract private investments, an investor-oriented approach is proposed, shifting the responsibility for defining and proposing the benefit-sharing mechanism to private actors and considering their contributions to globally agreed goals.
NEW SPACE-THE JOURNAL OF SPACE ENTREPRENEURSHIP AND INNOVATION
(2022)
Article
Astronomy & Astrophysics
Vishal Gajjar, Dominic LeDuc, Jiani Chen, Andrew P. V. Siemion, Sofia Z. Sheikh, Bryan Brzycki, Steve Croft, Daniel Czech, David DeBoer, Julia DeMarines, Jamie Drew, Howard Isaacson, Brian C. Lacki, Matt Lebofsky, David H. E. MacMahon, Cherry Ng, Imke de Pater, Karen I. Perez, Danny C. Price, Akshay Suresh, Claire Webb, S. Pete Worden
Summary: The search for extraterrestrial intelligence in radio frequencies has focused on narrowband signals. This study demonstrates that broadbamd pulsed beacons are more energetically efficient over longer time periods. The researchers conducted a detailed survey of 1883 stars using a convolutional neural network classifier, concluding that the existence of broadband pulsed beacons in our solar neighborhood is extremely rare.
ASTROPHYSICAL JOURNAL
(2022)
Editorial Material
Astronomy & Astrophysics
Paul C. W. Davies, S. Peter Worden
Article
Astronomy & Astrophysics
Christopher P. McKay, Paul C. W. Davies, Simon P. Worden
Summary: The possibility of habitable planets being common but life being rare is discussed in the article. If future telescopes confirm this, humans may consider seeding lifeless planets with resilient organisms or synthetic forms in order to ensure their survival. One potential method to achieve this is by using interstellar comets to transport microbial cargoes to nearby planetary systems. Conversely, it is also speculated that terrestrial life may have been intentionally seeded in this manner, which could be tested by finding evidence of common biochemical signatures on other Solar System bodies.
Article
Astronomy & Astrophysics
Peter Xiangyuan Ma, Cherry Ng, Leandro Rizk, Steve Croft, Andrew P. V. Siemion, Bryan Brzycki, Daniel Czech, Jamie Drew, Vishal Gajjar, John Hoang, Howard Isaacson, Matt Lebofsky, David H. E. MacMahon, Imke de Pater, Danny C. C. Price, Sofia Z. Z. Sheikh, S. Pete Worden
Summary: By using a state-of-the-art machine-learning method, researchers analyzed a 480-hour dataset of 820 nearby stars from the SETI Breakthrough Listen project and reduced the number of interesting signals significantly. Through further visual inspection, eight promising signals warranting further observations were identified. This study presents a deep-learning-based technosignature search that effectively reduces false positives, leading to the discovery of previously unidentified extraterrestrial intelligence signals.
Article
Engineering, Aerospace
Sara Seager, Janusz J. Petkowski, Christopher E. Carr, Sarag J. Saikia, Rachana Agrawal, Weston P. Buchanan, David H. Grinspoon, Monika U. Weber, Pete Klupar, Simon P. Worden, Iaroslav Iakubivskyi, Mihkel Pajusalu, Laila Kaasik
Summary: Scientists have been considering the potential existence of life in the clouds of Venus for over half a century. In situ atmospheric measurements using modern instruments can determine whether the cloud decks have the necessary characteristics to support life. A suite of instruments is proposed to measure the acidity, water content, presence of metals, organic material, and biosignature gases in the droplets. The mission also serves as preparation for sample return by studying the non-liquid cloud particles and informing collection and storage methods.
Proceedings Paper
Astronomy & Astrophysics
Steve Ertel, Kevin Wagner, Jarron Leisenring, Daniel Apai, Denis Defrere, Jeremy Dietrich, Joshua A. Eisner, Virginie Faramaz, William Hoffmann, Markus Kasper, Pete Klupar, Jared R. Males, Mark S. Marley, Helene Rousseau, Stephanie Sallum, Eckhart Spalding, Jordan M. Stone, S. Pete Worden
Summary: One of the main design considerations of the Large Binocular Telescope (LBT) was to resolve the habitable zones (HZs) of nearby stars at mid-infrared wavelengths. The LBT Interferometer (LBTI) utilizes the telescope's two 8.4m mirrors and their 22.7m separation to achieve high-angular resolution observations at thermal-infrared wavelengths. The LBTI team has successfully completed the Hunt for Observable Signatures of Terrestrial planetary Systems (HOSTS) using nulling-interferometry, and now plans to use Fizeau imaging interferometry to search for low-mass, HZ planets around suitable nearby stars.
OPTICAL AND INFRARED INTERFEROMETRY AND IMAGING VIII
(2022)
Article
Engineering, Aerospace
Sara Seager, Janusz J. Petkowski, Christopher E. Carr, David H. Grinspoon, Bethany L. Ehlmann, Sarag J. Saikia, Rachana Agrawal, Weston P. Buchanan, Monika U. Weber, Richard French, Pete Klupar, Simon P. Worden, Darrel Baumgardner
Summary: The Venus Life Finder (VLF) missions aim to assess the habitability of the Venusian clouds and search for signs of extraterrestrial life. The project, led by MIT, is focused on astrobiology and can be launched quickly and at a relatively low cost.
