You're using an outdated browser. Please upgrade to a modern browser for the best experience.
Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Ice Accretion on Fixed-Wing Unmanned Aerial Vehicle
UAV is an aircraft without an onboard human pilot. The main components of a UAV are the aircraft structure, ground control center (remote), payload (camera), and a data link for the communication between aircraft and ground control center. According to their structure, UAVs are classified into four broad categories: fixed-wing UAVs, rotary-wing UAVs, flapping-wing UAVs, and blimps. The operation of UAVs in high north regions is prone to three main challenges: low temperature, high wind speeds, and atmospheric icing. The ice accretion along a UAV structure causes deterioration of aerodynamic performance and structural characteristics leading to catastrophic failures.
  • 1.2K
  • 11 Apr 2022
Topic Review
Shape Memory Alloy Reinforced Self-Healing Metal Matrix Composites
Shape-memory alloys (SMAs) are among the newest and most popular smart/intelligent materials that can recover their original shape when heated above a critical temperature. Self-healing refers to the remarkable ability of a material to repair damage inflicted upon it, such as cracks or voids. A Metal Matrix Composite (MMC) is a composite material that consists of at least two constituent parts: a metal (or alloy) matrix and typically a ceramic or metallic reinforcement (which can be particles, fibers, or whiskers) to enhance strength, stiffness, and other specific properties.
  • 1.2K
  • 10 Aug 2023
Topic Review
Timeline of STS-51-L
STS-51-L mission timeline is a detailed timeline of events from the ignition of Challenger's main engines to the remote destruction of the two Solid rocket boosters (SRBs), and includes a transcript of crew conversations from the cockpit voice recorder on board the orbiter. STS-51-L was the twenty-fifth flight in the American Space Shuttle program, and marked the first time a civilian had flown aboard the Space Shuttle. The mission used Space Shuttle Challenger, which lifted off from launch pad 39B (LC-39B) on January 28, 1986, from Kennedy Space Center, Florida. The mission ended in disaster following the destruction of Challenger 73 seconds after lift-off, because of the failure of an O-ring seals on Challenger's right solid rocket booster, which led to the rapid disintegration of the Space Shuttle stack from overwhelming aerodynamic pressures. The seven-member crew was killed when the crew compartment hit the Atlantic Ocean at 333 km/h (207 mph), after two and a half minutes of freefall.
  • 1.2K
  • 22 Nov 2022
Biography
Nicholas Mayall
Nicholas Ulrich Mayall (May 9, 1906 – January 5, 1993) was an American observational astronomer. After obtaining his doctorate from the University of California, Berkeley, Mayall worked at the Lick Observatory, where he remained from 1934 to 1960, except for a brief period at MIT's Radiation Laboratory during World War II. During his time at Lick, Mayall contributed to astronomical knowledge
  • 1.2K
  • 17 Nov 2022
Topic Review
UAV Detection and Tracking in Urban Environments
Unmanned aerial vehicles (UAVs) have gained significant popularity across various domains, but their proliferation also raises concerns about security, public safety, and privacy. Consequently, the detection and tracking of UAVs have become crucial. Among the UAV-monitoring technologies, those suitable for urban Internet-of-Things (IoT) environments primarily include radio frequency (RF), acoustic, and visual technologies. 
  • 1.2K
  • 17 Oct 2023
Topic Review
Potentially Open Research Directions for Unmanned Aerial Vehicles
The open development axis for Unmanned Aerial Vehicles (UAVs)  involves creating a collaborative ecosystem where developers, researchers, and users can work together to build open source platforms, tools, and standards for UAV design, development, and operation. This approach allows for greater innovation and flexibility in the UAV industry, including the integration of AI and ML algorithms to enhance autonomous flight and decision-making capabilities. Further challenges and open research directions can be elaborated upon in the following points.
  • 1.2K
  • 21 Aug 2023
Topic Review
Wireless Communications and Power Transfer on Intra-Vehicular Applications
In the world of space systems and launchers in particular, there is always a strong demand for the reduction of the weight of all components/subsystems that are not related to the payload and simplification of the integration phase. A possible solution to both these problems is the replacement of cables and connectors with wireless systems for communication and power supply. 
  • 1.2K
  • 18 Feb 2024
Topic Review
Structural Health Monitoring of Solid Rocket Motors
In the realm of space exploration, solid rocket motors (SRMs) play a pivotal role due to their reliability and high thrust-to-weight ratio. Serving as boosters in space launch vehicles and employed in military systems, and other critical & emerging applications, SRMs’ structural integrity monitoring, is of paramount importance. Traditional maintenance approaches often prove inefficient, leading to either unnecessary interventions or unexpected failures. Condition-based maintenance (CBM) emerges as a transformative strategy, incorporating advanced sensing technologies and predictive analytics. By continuously monitoring crucial parameters such as temperature, pressure, and strain, CBM enables real-time analysis, ensuring timely intervention upon detecting anomalies, thereby optimizing SRM lifecycle management. Particularly, photonic sensors and fiber-optic sensors, demonstrate exceptional promise in CBM goals. Their enhanced sensitivity and broad measurement range allow for capturing subtle changes indicative of degradation or potential failures. These sensors enable comprehensive, non-intrusive monitoring of multiple SRM locations simultaneously. Integrated with data analytics, these sensors empower predictive analysis, facilitating SRM behavior prediction and optimal maintenance planning. Ultimately, CBM, bolstered by advanced photonic sensors, promises enhanced operational availability, reduced costs, improved safety, and efficient resource allocation in SRM applications.
  • 1.2K
  • 13 Mar 2024
Topic Review
Xoie (Rocket)
Masten Space Systems was an aerospace manufacturer startup company in Mojave, California (formerly in Santa Clara, California) that is developing a line of vertical takeoff, vertical landing (VTVL) rockets, initially for uncrewed research sub-orbital spaceflights and eventually intended to support robotic orbital spaceflight launches. In 2020, NASA awarded Masten a contract for a lunar lander mission; NASA is to pay Masten US$75.9 million for Masten to build and launch a lander called XL-1 to take NASA and other customer payloads to the south pole of the Moon. Masten Mission One will be Masten's first space flight; it is scheduled for launch in November 2023. The company filed for Chapter 11 bankruptcy on 28 July 2022. The company would later be purchased by Astrobotic Technology on 11 September 2022.
  • 1.1K
  • 15 Nov 2022
Topic Review
Hope Mars Mission
The Hope Mars Mission (Arabic: مسبار الأمل) also called Emirates Mars Mission, is a planned space exploration probe mission to Mars funded by the United Arab Emirates and built by the Mohammed bin Rashid Space Centre, the University of Colorado and Arizona State University and set for launch in 2020. The probe will study the climate daily and through seasonal cycles, the weather events in the lower atmosphere such as dust storms, as well as the weather on Mars different geographic areas. The probe will attempt to answer the scientific community questions of why Mars atmosphere is losing hydrogen and oxygen into space and the reason behind Mars drastic climate changes. The mission is being carried out by a team of Emirati engineers in collaboration with foreign research institutions, and is a contribution towards a knowledge-based economy in the UAE. The probe has been named Hope or Al-Amal (Arabic: الأمل) and it is scheduled to reach Mars in 2021, which coincides with the 50th anniversary of the United Arab Emirates' formation.
  • 1.1K
  • 14 Oct 2022
Topic Review
Cluster (Spacecraft)
Cluster was a constellation of four European Space Agency spacecraft which were launched on the maiden flight of the Ariane 5 rocket, Flight 501, and subsequently lost when that rocket failed to achieve orbit. The launch, which took place on Tuesday, 4 June 1996, ended in failure due to multiple errors in the software design: Dead code (running, but intentionally so only for Ariane 4) with inadequate protection against integer overflow led to an exception handled inappropriately—halting the whole inertial navigation system that otherwise would have been unaffected. This resulted in the rocket veering off its flight path 37 seconds after launch, beginning to disintegrate under high aerodynamic forces, and finally self-destructing by its automated flight termination system. The failure has become known as one of the most infamous and expensive software bugs in history. The failure resulted in a loss of more than US$370 million.
  • 1.1K
  • 08 Nov 2022
Topic Review
3D Textiles Based on Warp Knitted Fabrics
Fibre-reinforced composites (FRCs) are already well established in several industrial sectors such as aerospace, automotive, plant engineering, shipbuilding and construction. The technical advantages of FRCs over metallic materials are well researched and proven. The key factors for an even wider industrial application of FRCs are the maximisation of resource and cost efficiency in the production and processing of the textile reinforcement materials. Due to its technology, warp knitting is the most productive and therefore cost-effective textile manufacturing process. In order to produce resource-efficient textile structures with these technologies, a high degree of prefabrication is required. This reduces costs by reducing the number of ply stacks, and by reducing the number of extra operations through final path and geometric yarn orientation of the preforms. 
  • 1.1K
  • 26 May 2023
Topic Review
Mars In Situ Resource Utilization Technologies
Exploration of Mars with a human crew is widely viewed as the ultimate culmination of planetary exploration. Initial human landing on Mars would be limited to the simple in situ resource utilization (ISRU) based on atmosphere only, which is immediately accessible without the challenge of remote, autonomous mining of regolith, transporting regolith, and processing regolith. In a second generation of missions, it might be possible to include processing regolith, either for hydrated minerals or for imbedded ice.
  • 1.1K
  • 22 Jan 2024
Topic Review
BVLOS Unmanned Aircraft Operations in Forest Environments
Beyond Visual Line of Sight (BVLOS) operations are attractive within forest environments because they remove the need for any pilot or visual observer to maintain Visual Line of Sight (VLOS) with the aircraft and the surrounding airspace. Technically speaking, even basic prosumer-grade unmanned aircraft are capable of BVLOS flight. However, they lack the technical capabilities to mitigate ground-based and airborne risks to the extent necessary to do this in a compliant manner with aviation regulations. There are also operational considerations around airspace use and organisational procedures, as well as other considerations such as those relating to human factors.
  • 1.1K
  • 15 Jul 2022
Topic Review
Microwave Sounding Unit Temperature Measurements
Microwave Sounding Unit temperature measurements refers to temperature measurement using the Microwave Sounding Unit instrument and is one of several methods of measuring Earth atmospheric temperature from satellites. Microwave measurements have been obtained from the troposphere since 1979, when they were included within NOAA weather satellites, starting with TIROS-N. By comparison, the usable balloon (radiosonde) record begins in 1958 but has less geographic coverage and is less uniform. Microwave brightness measurements do not directly measure temperature. They measure radiances in various wavelength bands, which must then be mathematically inverted to obtain indirect inferences of temperature. The resulting temperature profiles depend on details of the methods that are used to obtain temperatures from radiances. As a result, different groups that have analyzed the satellite data have obtained different temperature trends. Among these groups are Remote Sensing Systems (RSS) and the University of Alabama in Huntsville (UAH). The satellite series is not fully homogeneous – the record is constructed from a series of satellites with similar but not identical instrumentation. The sensors deteriorate over time, and corrections are necessary for satellite drift in orbit. Particularly large differences between reconstructed temperature series occur at the few times when there is little temporal overlap between successive satellites, making intercalibration difficult.
  • 1.1K
  • 04 Nov 2022
Topic Review
Ceramic Composites in Aeronautics and Aerospace
The quest for increased performance in the aeronautical and aerospace industries has provided the driving force and motivation for the research, investigation, and development of advanced ceramics. Special emphasis is therefore attributed to the ability of fine ceramics to fulfill an attractive, extreme, and distinguishing combination of application requirements. This research provides an extensive discussion and review of the thermal protection systems (TPS), thermal protection barriers (TBC), and dielectric barrier discharge (DBD) plasma actuators, and discusses the concept of multifunctional advanced ceramics for future engineering needs and perspectives.
  • 1.1K
  • 02 Feb 2023
Topic Review
AI-Based Surface Roughness Prediction for Additively Manufactured Components
Additive manufacturing has gained significant popularity from a manufacturing perspective due to its potential for improving production efficiency. However, ensuring consistent product quality within predetermined equipment, cost, and time constraints remains a persistent challenge. Surface roughness, a crucial quality parameter, presents difficulties in meeting the required standards, posing significant challenges in industries such as automotive, aerospace, medical devices, energy, optics, and electronics manufacturing, where surface quality directly impacts performance and functionality. Artificial intelligence (AI) is one of the methods used by researchers to predict the surface quality of additively fabricated parts. 
  • 1.1K
  • 23 Oct 2023
Topic Review
Timeline of Rosetta Spacecraft
Rosetta is a space probe designed to rendezvous with the comet 67P/Churyumov–Gerasimenko, perform flybys of two asteroids (2867 Šteins and 21 Lutetia), and carry lander Philae until its landing on 67P. This page records a detailed timeline of this mission.
  • 1.1K
  • 27 Oct 2022
Topic Review
DubaiSat-1
DubaiSat-1 is a remote sensing Earth observation satellite built by the Emirates Institution for Advanced Science and Technology (EIAST) under an agreement with Satrec Initiative, a satellite manufacturing company in South Korea . DubaiSat-1 was launched on 29 July 2009 into a 680 km altitude sun-synchronous polar orbit from the Baikonur launch site in Kazakhstan, along with several other satellites on board the Dnepr launch vehicle.
  • 1.1K
  • 24 Nov 2022
Topic Review
In-Space Propulsion Technologies
Proposed in-space propulsion technologies describe the propulsion technologies that could meet future space science and exploration needs. These propulsion technologies are intended to provide effective exploration of our Solar System and will permit mission designers to plan missions to "fly anytime, anywhere, and complete a host of science objectives at the destinations" and with greater reliability and safety. With a wide range of possible missions and candidate propulsion technologies, the question of which technologies are "best" for future missions is a difficult one. A portfolio of propulsion technologies should be developed to provide optimum solutions for a diverse set of missions and destinations. In-space propulsion begins where the upper stage of the launch vehicle leaves off; performing the functions of primary propulsion, reaction control, station keeping, precision pointing, and orbital maneuvering. The main engines used in space provide the primary propulsive force for orbit transfer, planetary trajectories and extra planetary landing and ascent. The reaction control and orbital maneuvering systems provide the propulsive force for orbit maintenance, position control, station keeping, and spacecraft attitude control.
  • 1.1K
  • 21 Oct 2022
  • Page
  • of
  • 11
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of COVID-19
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Academic Video Service
Feedback