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Topic Review
Satellite Navigation Signal Authentication Principles and Technical Architecture
As the Global Navigation Satellite System (GNSS) is widely used in all walks of life, the signal structure of satellite navigation is open, and the vulnerability to spoofing attacks is also becoming increasingly prominent, which will seriously affect the credibility of navigation, positioning, and timing (PNT) services. Satellite navigation signal authentication technology is an emerging technical means of improving civil signal anti-spoofing on the satellite navigation system side, and it is also an important development direction and research focus of the GNSS. 
  • 1.5K
  • 12 Apr 2023
Topic Review
Vanguard TV3
Vanguard TV3, also called Vanguard Test Vehicle Three was the first attempt of the United States to launch a satellite into orbit around the Earth. Vanguard 1A was a small satellite designed to test the launch capabilities of the three-stage Vanguard and study the effects of the environment on a satellite and its systems in Earth orbit. It was also to be used to obtain geodetic measurements through orbit analysis. Solar cells on Vanguard 1A were manufactured by Bell Laboratories. At its launch attempt on December 6, 1957, at Cape Canaveral Air Force Station , the booster ignited and began to rise, but about two seconds after liftoff, after rising about four feet (1.2 m), the rocket lost thrust and fell back to the launch pad. As it settled the fuel tanks ruptured and exploded, destroying the rocket and severely damaging the launch pad. The Vanguard satellite was thrown clear and landed on the ground a short distance away with its transmitters still sending out a beacon signal. The satellite was damaged, however, and could not be reused. It is now on display at the National Air and Space Museum of the Smithsonian Institution. The exact cause of the accident was not determined with certainty, but it appeared that the fuel system malfunctioned. Other engines of the same model were modified and did not fail.
  • 1.5K
  • 25 Oct 2022
Topic Review
Liquid Cooling and Ventilation Garment
A Liquid Cooling Garment (LCG) is a form-fitting garment that is used to remove body heat from the wearer in environments where evaporative cooling from sweating and open-air convection cooling does not work, or the wearer has a biological problem that hinders self-regulation of body temperature. A Liquid Cooling and Ventilation Garment (LCVG) has additional crush-resistant ventilation ducts, which draw moist air from the wearer's extremities, keeping the wearer dry. In a fully enclosing suit where exhaled breathing air can enter the suit, the exhaled air is moist and can lead to an uncomfortable feeling of dampness or wetness. While this technology is most commonly associated with space suits, it is also used in a wide range of Earth-bound applications where open-air cooling is difficult or impossible to achieve, such as fire fighting, working in a steel mill and increasingly by surgeons during long or strenuous procedures.
  • 1.4K
  • 08 Oct 2022
Topic Review
Sonic Boom Prediction and Minimization
NASA describes the sonic boom as “thunder-like noise a person on the ground hears when an aircraft […] flies overhead faster than the speed of sound”. Sonic boom results from the coalescence of the shock waves generated by an aircraft flying supersonicly trough their propagation into the atmosphere to the ground.
  • 1.4K
  • 08 Nov 2023
Topic Review
Balloon Satellite
A balloon satellite (also occasionally referred to as a "satelloon", which is a trademarked name owned by Gilmore Schjeldahl's G.T. Schjeldahl Company) is a satellite that is inflated with gas after it has been put into orbit.
  • 1.4K
  • 17 Oct 2022
Topic Review
Gravity Field and Steady-State Ocean Circulation Explorer
The Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) was the first of ESA's Living Planet Programme satellites intended to map in unprecedented detail the Earth's gravity field. The spacecraft's primary instrumentation was a highly sensitive gravity gradiometer consisting of three pairs of accelerometers which measured gravitational gradients along three orthogonal axes. Launched on 17 March 2009, GOCE mapped the deep structure of the Earth's mantle and probed hazardous volcanic regions. It brought new insight into ocean behaviour; this in particular, was a major driver for the mission. By combining the gravity data with information about sea surface height gathered by other satellite altimeters, scientists were able to track the direction and speed of geostrophic ocean currents. The low orbit and high accuracy of the system greatly improved the known accuracy and spatial resolution of the geoid (the theoretical surface of equal gravitational potential on the Earth). The satellite's unique arrow shape and fins helped keep GOCE stable as it flew through the thermosphere at a comparatively low altitude of 255 kilometres (158 mi). Additionally, an ion propulsion system continuously compensated for the variable deceleration due to air drag without the vibration of a conventional chemically powered rocket engine, thus limiting the errors in gravity gradient measurements caused by non-gravitational forces and restoring the path of the craft as closely as possible to a purely inertial trajectory. After running out of propellant, the satellite began dropping out of orbit and made an uncontrolled reentry on 11 November 2013.
  • 1.4K
  • 02 Nov 2022
Topic Review
Applications of Unmanned Aerial Vehicles during COVID-19
Unmanned aerial vehicles (UAVs), also referred to as drones, have received momentous attention in various domains of civil and military operations because of their high mobility, enhanced stability, low cost, and high endurance in multiple tasks.
  • 1.4K
  • 21 Oct 2022
Biography
Barnes Wallis
Sir Barnes Neville Wallis CBE FRS RDI FRAeS[1] (26 September 1887 – 30 October 1979), was an English scientist, engineer and inventor. He is best known for inventing the bouncing bomb used by the Royal Air Force in Operation Chastise (the "Dambusters" raid) to attack the dams of the Ruhr Valley during World War II. The raid was the subject of the 1955 film The Dam Busters, in which Wallis wa
  • 1.4K
  • 06 Dec 2022
Topic Review
List of Soviet Manned Space Missions
This is a list of the manned space missions conducted by the Soviet space programme. These missions belong to the Vostok, Voskhod, and Soyuz space programs. Note: Soviet manned space missions had not any official patches before Apollo–Soyuz program. After that and until Soyuz TM-12 "Juno" flight mission patches had been designed only for international missions.
  • 1.3K
  • 06 Dec 2022
Topic Review
BFR (Rocket)
The Big Falcon Rocket (officially shortened to BFR) is a privately funded fully reusable launch vehicle and spacecraft system in development by SpaceX. The overall space vehicle architecture includes both launch vehicles and spacecraft, as well as ground infrastructure for rapid launch and relaunch, and zero-gravity propellant transfer technology to be deployed in low Earth orbit (LEO). The payload capacity to Earth orbit of at least 100,000 kg (220,000 lb) makes BFR a super heavy-lift launch vehicle. The first orbital flight is tentatively planned for 2020. SpaceX has been developing a super heavy-lift launch vehicle for many years, with the exact design and nomenclature of the vehicle undergoing multiple revisions over time. Before 2016, the vehicle was referred to as the Mars Colonial Transporter (MCT), though very few details about the design of the MCT were ever made public. Starting from 2016, SpaceX began sharing annual updates with the public, detailing the designs and uses of their upcoming new launch vehicle. In 2016, SpaceX CEO Elon Musk presented the vehicle at the International Astronautical Congress as the ITS launch vehicle, forming a core part of Musk's comprehensive vision for an Interplanetary Transport System (ITS). The ITS vehicle had a 12-meter (39 ft) core diameter, but was only intended for interplanetary travel. In September 2017, the design (now known as the BFR) was scaled down to 9 meters (30 ft) While the ITS had been solely aimed at Mars transit and other interplanetary uses, SpaceX pivoted to a plan that would support all SpaceX launch service provider capabilities with a single set of 9-meter vehicles: Earth orbit, lunar orbit, Interplanetary spaceflight, and potentially, even intercontinental passenger transport on Earth. In September 2018, a redesign of the second stage was announced, adding steerable canards, two radially adjustable fins also acting as landing legs, and a third leg that looks like a vertical stabilizer but has no aerodynamic function due to the special re-entry profile of the spacecraft. The launch vehicle design is dependent on the concurrent development work on the Raptor rocket engines, which are cryogenic methalox-fueled engines to be used for both stages of the BFR launch vehicle. Development on the Raptor began in 2012, leading to engine testing which began in 2016. The BFR system is intended to completely replace all of SpaceX's existing space hardware (the Falcon 9 and Falcon Heavy launch vehicles, and the Dragon spacecraft), initially aiming at the Earth-orbit launch market, but explicitly adding substantial capability to support long-duration spaceflight in the cislunar and Mars transport flight environments.
  • 1.3K
  • 14 Nov 2022
Topic Review
Fiber Metal Laminates
Composite materials such as Fibre Metal Laminates (FMLs) have attracted the interest of the aerospace and automotive industries due to their high strength to weight ratio, but to use them as structures it is necessary to master the manufacturing and wiring techniques of these materials. The process parameters used in multi-material machining, such as drilling and milling, tool geometry, tool coating, lubricants and coolants, must be well established to achieve a successful machining process in FLM materials. Failure of any of these parameters can cause irreparable damage to the material, wasting the process and making it less sustainable. Understanding the failure process is essential to improve the accuracy of the analysis, to supplement the information and to provide a deterrent to adjusting process parameters.
  • 1.3K
  • 19 Apr 2023
Topic Review
Metal Additive Manufacturing for Satellites and Rockets
Additive manufacturing (AM), also called 3D printing, belongs to the emerging technologies of our time. After being used for rapid prototyping at the beginning, current rapid production is enabled for many applications due to increasingly improved technologies. One of the areas inh which additive manufacturing offers many advantages compared to conventional manufacturing techniques is space exploration, especially producing parts of satellites and rockets.
  • 1.3K
  • 20 Dec 2021
Topic Review
Mohammed Bin Rashid Space Centre
The Mohammed Bin Rashid Space Centre (MBRSC) (Arabic: مركز محمد بن راشد للفضاء), is a Dubai government organisation working on the UAE space program, which includes various space satellite projects, the Emirates Mars Mission, and the UAE astronaut programme. The centre actively works to promote space science and research in the region. The centre encompasses the Emirates Institution for Advanced Science and Technology (EIAST).
  • 1.3K
  • 25 Oct 2022
Topic Review
Spoken ATC Instruction Understanding
Spoken ATC Instruction Understanding means in air traffic control, speech communication with radio transmission is the primary way to exchange information between the controller and aircrew. A wealth of contextual situational dynamics is embedded implicitly; thus, understanding the spoken instruction is particularly significant to the ATC research. ATC is a complicated and time-varying system, in which operational safety is always a hot research topic. All achievements of an ATC center can be vetoed without any hesitation if any safety incident occurs. Air traffic safety is affected by various aspects of air traffic operation, from mechanical maintenance, resource management, to air traffic control. The safety of air traffic control is particularly important since the aircraft is already in the air. There is no doubt that any effort deserves to be made to improve ATC safety.
  • 1.3K
  • 06 Apr 2021
Topic Review
DAVINCI+
DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging, Plus) is a planned mission for an orbiter and atmospheric probe to the planet Venus. Together with the VERITAS mission, which will also study Venus, it was selected by NASA on 2 June 2021 to be part of their Discovery Program. DAVINCI+ will send both an orbiter and a descent probe to Venus. The orbiter will image Venus in multiple wavelengths from above, while the descent probe will study the chemical composition of Venus' atmosphere and take photographs during descent. The DAVINCI+ probe will travel through the Venusian atmosphere, sampling the atmosphere, and returning measurements down to the surface. These measurements are important to understanding the origin of the atmosphere, how it has evolved, and how and why it is different from the atmosphere of Earth and Mars. The measurements taken by DAVINCI+ will investigate the possible history of water on Venus and the chemical processes at work in the unexplored lower atmosphere. Before it reaches the surface, the DAVINCI+ probe will capture high resolution images of the planet's ridged terrain ("tesserae"), returning the first images of the planet's surface since Soviet Venera 13 lander in 1981. It will also collect data for studying the planet's origin, and its tectonic and weathering history.
  • 1.3K
  • 17 Oct 2022
Topic Review
Non-Destructive Evaluation of Structural Composite Materials
The growing demand and diversity in the application of industrial composites and the current inability of present non-destructive evaluation (NDE) methods to perform detailed inspection of these composites has motivated this comprehensive review of sensing technologies. NDE has the potential to be a versatile tool for maintaining composite structures deployed in hazardous and inaccessible areas, such as offshore wind farms and nuclear power plants. Therefore, the future composite solutions need to take into consideration the niche requirements of these high-value/critical applications. Composite materials are intrinsically complex due to their anisotropic and non-homogeneous characteristics. This presents a significant challenge for evaluation and the associated data analysis for NDEs. For example, the quality assurance, certification of composite structures, and early detection of the failure is complex due to the variability and tolerances involved in the composite manufacturing. Adapting existing NDE methods to detect and locate the defects at multiple length scales in the complex materials represents a significant challenge, resulting in a delayed and incorrect diagnosis of the structural health. This paper presents a comprehensive review of the NDE techniques, that includes a detailed discussion of their working principles, setup, advantages, limitations, and usage level for the structural composites. A comparison between these techniques is also presented, providing an insight into the future trends for composites’ prognostic and health management (PHM). Current research trends show the emergence of the non-contact-type NDE (including digital image correlation, infrared tomography, as well as disruptive frequency-modulated continuous wave techniques) for structural composites, and the reasons for their choice over the most popular contact-type (ultrasonic, acoustic, and piezoelectric testing) NDE methods is also discussed. The analysis of this new sensing modality for composites’ is presented within the context of the state-of-the-art and projected future requirements.
  • 1.3K
  • 20 Dec 2021
Topic Review
Evolved Expendable Launch Vehicle
Evolved Expendable Launch Vehicle (EELV) is an expendable launch system program of the United States Air Force (USAF), intended to assure access to space for Department of Defense and other United States government payloads. The program, which began in the 1990s with the goal of making government space launches more affordable and reliable, resulted in the development of the Delta IV and Atlas V. Along with the newer Falcon 9, these launch systems are the primary methods for launching U.S. military satellites. The USAF plans to use the EELV family of launch vehicles until at least 2030. Follow-on technologies are being considered, one of which was the Reusable Booster System, discontinued in 2012.
  • 1.3K
  • 14 Oct 2022
Biography
Edward Gibson
Edward George Gibson (born November 8, 1936) is a former NASA astronaut, pilot, engineer, and physicist. Before becoming a NASA astronaut, Gibson graduated from the University of Rochester and the California Institute of Technology. He became a research assistant in jet propulsion while completing his studies and eventually became a research scientist for Philco Corporation until joining NASA.
  • 1.2K
  • 15 Nov 2022
Topic Review
Shuttle-Derived Launch Vehicle
Shuttle-Derived Launch Vehicle (SDLV), or simply Shuttle-Derived Vehicle (SDV), is a term describing one of an array of concepts that have been developed for building space launch vehicles using the already developed components, technology, and infrastructure of the Space Shuttle program. In the late 1980s and early 1990s, NASA formally studied a cargo-only vehicle, Shuttle-C, that would have supplemented the crewed Space Shuttle. In 2005, NASA was developing the Ares I and Ares V launch vehicles, based in part on highly modified Shuttle components, to enable exploration of the Moon and Mars. The agency also studied a third such vehicle, the Ares IV.
  • 1.2K
  • 29 Nov 2022
Topic Review
Signal Processing of Pulsed Thermography for Enhanced Detectability
Non-destructive testing (NDT) is a broad group of testing and analysis techniques used in science and industry to evaluate the properties of a material, structure, or system for characteristic defects and discontinuities without causing damage. Recently, infrared thermography is one of the most promising technologies as it can inspect a large area quickly using a non-contact and non-destructive method. Moreover, thermography testing has proved to be a valuable approach for non-destructive testing and evaluation of structural stability of materials. Pulsed thermography is one of the active thermography technologies that utilizes external energy heating. However, due to the non-uniform heating, lateral heat diffusion, environmental noise, and limited parameters of the thermal imaging system, there are some difficulties in detecting and characterizing defects.
  • 1.2K
  • 17 Jan 2022
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