Increasing The Density Value Of Composite Propellant Ap/Htpb/Al For Rocket Performance Using The Sphere Packing Model,
2026
Department of Physics, Faculty of Mathematics and Natural Sciences, University of Indonesia, Depok 16424, Indonesia
Increasing The Density Value Of Composite Propellant Ap/Htpb/Al For Rocket Performance Using The Sphere Packing Model, Muhammad Iqbal Alfikri, Bayu Prianto, Ariadne Lakshmidevi Juwono
Makara Journal of Science
This research employs the sphere packing volume (SPV) model to optimize the density of composite propellants thereby enhancing rocket performance. We systematically varied the diameters of spherical ammonium perchlorate (AP) particles (50 and 400 µm) and aluminum powder (Al) particles (10 and 30 µm). These particles were incorporated at an ideal AP:Al ratio of 4:1 into a matrix of hydroxyl-terminated polybutadiene and toluene diisocyanate. By adjusting the AP ratio for each Al particle size and considering theoretical and tap densities, we precisely calculated the SPV value for each composition. The composition with the highest SPV value yielded remarkable results. This …
Retraction Notice To "Hydrogen Recovery, Cleaning, Compression, Storage, Dispensing, Distribution System And End-Uses On The University Campus From Combined Heat, Hydrogen And Power System" [International Journal Of Hydrogen Energy 39 (2014) 647-653],
2026
Missouri University of Science and Technology
Retraction Notice To "Hydrogen Recovery, Cleaning, Compression, Storage, Dispensing, Distribution System And End-Uses On The University Campus From Combined Heat, Hydrogen And Power System" [International Journal Of Hydrogen Energy 39 (2014) 647-653], Tarek A. Hamad, Abdulhakim A. Agll, Yousif M. Hamad, Sushrut Bapat, Mathew Thomas, Kevin B. Martin, John W. Sheffield
Engineering Management and Systems Engineering Faculty Research & Creative Works
This article has been retracted: please see Elsevier policy on Article Correction, Retraction and Removal (https://www.elsevier.com/about/policies-and-standards/article-withdrawal). This article has been retracted at the request of the Editor.
Application Of Machine Learning To Discover Dynamical Structures In 4d Poincaré Maps In The Circular Restricted Three-Body Problem,
2026
Air Force Institute of Technology
Application Of Machine Learning To Discover Dynamical Structures In 4d Poincaré Maps In The Circular Restricted Three-Body Problem, Kevin M. Trigg, Daniel J. Broyles, Robert A. Bettinger, Tyler J. Kapolka
Faculty Publications
The spatial Circular Restricted Three-Body Problem (CR3BP) produces complex orbital dynamics that are difficult to classify at scale using traditional, manual Poincaré map analysis. A Poincaré map simplifies continuous orbital motion by recording the points where a trajectory intersects a chosen surface in phase space, converting a continuous path into a discrete set of crossings that reveal underlying topological structure. These crossings make it easier to characterize trajectory behavior, but interpreting them visually becomes impractical for large datasets and as Poincaré maps evolve from two into four dimensions. To address this challenge, an unsupervised clustering pipeline for discovering dynamical structures …
The Evolution Of Reliability Methods For Nondestructive Evaluation (Nde): From Probability Of Detection (Pod) Conception To Contemporary Practices,
2026
Air Force Research Laboratory
The Evolution Of Reliability Methods For Nondestructive Evaluation (Nde): From Probability Of Detection (Pod) Conception To Contemporary Practices, Christine E. Knott, Jennifer Brown, John Aldrin, Christine M. Schubert Kabban
Faculty Publications
Nondestructive evaluation (NDE) methods are powerful tools for detecting and characterizing flaws in structural components, but their reliability must be evaluated before they can be used in critical applications. For more than 50 years, probabilistic and statistical methods have been used effectively to estimate reliability by describing an NDE system’s Probability of Detection (POD) for flaws of realistic sizes. The POD methods used by the USAF and NASA, like Hit/Miss, Signal-Response (â vs. a), and Point Estimate method (PEM, a.k.a. 29/29) have evolved, alongside newer approaches like Limited Sample POD (LS-POD) method, and Model Assisted Probability of Detection …
Notes For The Contributors,
2026
University of Nebraska at Omaha
The Global Chessboard: Strategic Deterrence In A New Era Of Great Power Competition,
2026
University of Nebraska at Omaha
The Global Chessboard: Strategic Deterrence In A New Era Of Great Power Competition, The 66th Annual Academy Assembly
Space and Defense
The 66th annual Academy Assembly brought together twenty-seven student delegates from civilian institutions and sister military service academies to discuss urgent issues in national affairs. This national student congress was held during March 3-5, 2026 and produced the following committee reports.
Critical Strategic Deterrence Questions For Today,
2026
Missouri State University
Critical Strategic Deterrence Questions For Today, Keith B. Payne
Space and Defense
r. Payne visited the U.S. Air Force Academy to offer keynote remarks at a national student congress, the 66th Academy Assembly, held during March 3-5,2026 and dedicated to the topic of the Global Chessboard: Strategic Deterrence in a New Era of Great Power Competition. Dr. Payne is co-founder of the National Institute for Public Policy, former Department Head at the Graduate School of Defense and Strategic Studies, Missouri State University, a former Deputy Assistant Secretary of Defense, and former Senior Advisor to the Office of the Secretary of Defense. He has authored or co-authored over 230 published articles and 50 …
Death Of Battlefield Hide-And-Seek,
2026
Columbia University
Death Of Battlefield Hide-And-Seek, Lily Cheatham
Space and Defense
For the past twenty years, the stealth regime defined military thinking, prioritizing technologies and tactics designed to evade enemy defense systems. Ensuring radar invisibility and maintaining information dominance have been the keys to survival and strategic advantage. On June 21-22, 2025, the United States conducted "Operation Midnight Hammer" against Iranian nuclear facilities at Fordow, Natanz, and Isfahan. The principal strike package included seven B-2 Spirit stealth bombers, whose crews flew approximately 18 hours to reach the target area and roughly 36 hours and 13,000 miles round trip. The B-2s dropped 14 GBU-57 Massive Ordnance Penetrators on Fordow and Natanz, marking …
The Baltic Bear Trap Wargame,
2026
U.S. Air Force Academy
The Baltic Bear Trap Wargame, Connor Crookham
Space and Defense
Modern military education increasingly relies on experiential tools that allow students to explore the complexity of contemporary conflict in ways that lectures and readings alone cannot achieve. Nowhere is this more evident than in the emerging emphasis on multi-domain operations, integrated deterrence, and the blurred boundaries between competition and armed conflict. The Baltic Bear Trap wargame was developed as a student design project to meet this instructional need, offering a structured environment in which players must think, plan, and act as operational-level decision makers confronting a deteriorating security situation in the Nordic–Baltic region. Built for use at the Swedish Defense …
A Cislunar Economic Forecast Under Public-Private Partnership,
2026
University of Colorado, Boulder
A Cislunar Economic Forecast Under Public-Private Partnership, Naisha Chirag Naik
Space and Defense
Cislunar space, spanning Earth’s orbit to the Moon, has emerged as a new frontier due to its strategic, scientific, and economic potential, with growing involvement from global powers, governments, and private entities diversifying the market. Unlike the first lunar space race, which saw a spike in activity amongst two countries followed by “silence,” the current cislunar era is hallmarked by a growing mix of public agencies, private companies, and international actors seeking to gain a foothold in what could be the foundation for a long-term space economy. While cislunar space was historically only an interest for superpowers, recent years have …
Autonomous Navigation In Cislunar Satellites,
2026
University of Texas, Austin
Autonomous Navigation In Cislunar Satellites, Heith Johnson
Space and Defense
Cislunar space—the region between Earth’s geosynchronous orbit (about 36,000 kilometers from Earth) and the Moon (roughly 384,000 kilometers away)—is becoming a critical frontier for future space exploration and commercialization.1 This zone includes the Moon’s orbit, transfer orbits, and the Earth-Moon Lagrange points. Additionally, as more nations and corporations launch lunar missions and establish long-term infrastructure, cislunar space is increasingly becoming a strategic focus for exploration, logistics, and transportation.
Planetary Defense As The Ethico-Legal Gateway For International Space Security,
2026
Swinburne University of Technology - Australia
Planetary Defense As The Ethico-Legal Gateway For International Space Security, Evie Kendal
Space and Defense
Following the news in late 2024 that there was a city-killer asteroid on a possible collision course with Earth, many members of the public were shocked to learn there was no reliable global plan for managing such asteroidal and cometary impact hazards. While calculations of Asteroid 2024 YR4’s trajectory were further refined to exclude the previously reported 2-3% chance of collision in 2032, this event highlighted a major security threat: the lack of a globally coordinated, appropriately resourced, and politically supported planetary defense strategy (Gibney, 2025). In so doing, it also provided an opportunity for security experts to consider the …
Space-Based Missile Defense With Early Interceptor Launch Strategies,
2026
University of Michigan, Ann Arbor
Space-Based Missile Defense With Early Interceptor Launch Strategies, William Priedhorsky, James Wells
Space and Defense
There is renewed interest in space-based boost-phase intercept (SBPI) for missile defense against ICBMs of near-peer adversaries. We discuss SBPI in the context of other missile defense approaches, and address one of its challenges, which is the expense of fielding a large enough constellation of interceptors in space to counter even a small number of ICBMs. We develop an early-launch approach that could substantively reduce the required density of interceptors. Because every second matters in boost-phase defense, early launch of interceptors can significantly increase the reach of each interceptor. Early launch would require interceptors that have highly throttleable motors. Our …
Golden Dome: Seeking Space Security,
2026
Johns Hopkins University
Golden Dome: Seeking Space Security, Namrata Goswami
Space and Defense
The “Golden Dome” initiative [formerly Iron Dome] was announced by President Donald Trump on January 27, 2025, signifying a transformative shift in global space security policy. It fundamentally questions long-standing assumptions about deterrence, national vulnerability to missile attacks, and the role of space in strategic defense. More importantly, it emerges at a moment of acute strategic transition: the erosion of Cold War arms control frameworks, the rapid advancement of hypersonic and orbital delivery systems, and the growing integration of space into warfighting doctrines. Launched via a presidential memorandum in January 2025, Golden Dome calls for a layered missile defense system …
Space & Defense Vol. 17 No. 1 Editor's Note,
2026
University of Nebraska at Omaha
Space & Defense Vol. 17 No. 1 Editor's Note, Damon Coletta
Space and Defense
No abstract provided.
Space & Defense Vol. 17 No. 1 Table Of Contents,
2026
University of Nebraska at Omaha
Space & Defense Vol. 17 No. 1 Table Of Contents, Space & Defense
Space and Defense
No abstract provided.
Space & Defense Vol. 17 No. 1 Front Matter,
2026
University of Nebraska at Omaha
Space & Defense Vol. 17 No. 1 Front Matter, Space & Defense
Space and Defense
No abstract provided.
Space & Defense Volume 17 Issue 1 Summer 2026 (Whole Issue),
2026
University of Nebraska at Omaha
Space & Defense Volume 17 Issue 1 Summer 2026 (Whole Issue), Space & Defense
Space and Defense
No abstract provided.
In-Orbit Demonstration Of The Vyom-2u: A Green Monopropellant-Based Propulsion System Onboard Isro's Pslv C60 Poem-4,
2026
Manastu Space Technologies
In-Orbit Demonstration Of The Vyom-2u: A Green Monopropellant-Based Propulsion System Onboard Isro's Pslv C60 Poem-4, Ashtesh Kumar, Tushar Jadav, Prashant Singh, Rajat Kumar, Sajo George, Sivakami S., Rohit Shanbhag, Neel Gharat, Shubham Singh, Henry Sam, Suman Vadla
Small Satellite Conference
Vyom 2U is a compact 2U green monopropellant propulsion system designed to deliver a total impulse of 1700 Ns. At Beginning-of-Life (BOL) conditions, corresponding to a tank pressure of 24 bar, the thruster can deliver up to 1.1 N with a specific impulse of approximately 250 s, while requiring a peak electrical power of 15 W. At an operating pressure of 14 bar, the propulsion system delivers a thrust of approximately 0.67 N with a specific impulse of about 238 s. This operating point was deliberately selected for in-orbit operations to maintain sub-newton thrust levels compatible with the attitude control …
Payload Selection To Correlate Shielding Performance With Molecular Structure And Elemental Composition For Rosisat: The Radiation Orbital Shielding Investigation Satellite,
2026
Embry-Riddle Aeronautical University
Payload Selection To Correlate Shielding Performance With Molecular Structure And Elemental Composition For Rosisat: The Radiation Orbital Shielding Investigation Satellite, Chase Patterson, Jacob L. Blanton, Kylie Nager
Beyond: Undergraduate Research Journal
Exposure to space weather in the Low Earth Orbit (LEO) environment poses significant challenges to both the integrity and longevity of orbital hardware, as well as the health of astronauts, driving the necessity for improved means of radiation shielding for future missions. With a 1U CubeSat formfactor, ROSISat is a planned LEO mission that aims to characterize the radiation shielding capabilities of seven candidate materials: ultra-high molecular weight polyethylene, boron nitride, carbon nanotubes, boron nitride nanotubes with polyethylene fibers, carbon fiber reinforced composite, and aerographene, as well as two control materials: aluminum 6061 and ep33. By comparing the shielding performance …
