Search

The global space industry is booming. While governmental agencies used to dominate outer space activities, private space organizations (PSOs) now launch rockets, operate strategic satellites, and even take tourists on space expeditions. How can we explain this emergence of PSOs? Building on organizational ecology theory and drawing on a novel dataset of 1751 space organizations and 52 semi-structured interviews, this paper finds that mutualistic relations between governmental space agencies and PSOs have been instrumental in the rise of PSOs. This emphasis on mutualism challenges the prevailing belief that a few visionary private entrepreneurs create the space industry from the ground up. It also refutes the notion that PSOs simply out-compete a stagnant public sector. PSOs have not superseded governmental space agencies; they are nurtured by and developed with them. This paper is one of the first to explain how private actors can emerge in a field historically dominated by governmental actors. In so doing, it contributes to studies on public-private interactions by showing how mutualism can structure a nascent industry. It also opens up new avenues for research on the political economy of outer space by making available a rich dataset of space actors. [ABSTRACT FROM AUTHOR]

The study of the transient combustion modes is one of the key topics when considering the safety of space flights. Control of detonation onset has a dual application. First, the search for ways to prevent detonation modes in case of accidental fuel releases for fire safety issues of launch systems and the avoidance of accidents with rocket engines at a launch site and in near-Earth space. Second, the study of detonation and the possibility of using it to create propulsion systems based on detonation combustion of fuel. The paper shows the effect of the presence of spatial non-uniformities on the promotion of detonation in the chamber. Various geometries with and without obstacles and cavities are considered. It is demonstrated that the presence of obstacles accelerates the transition to the detonation process on the one hand, but on the other hand the presence of obstacles in combustion chamber could be the cause of incidental uncontrolled ignition, which ruins stable operation of an engine. The results of theoretical studies of the working cycle of the combustion chamber of a pulsed detonation engine are presented. Theoretical estimates for thrust characteristics are obtained. • The possibility of using detonation for developing new type of Space engine is demonstrated. • Different configuration of obstacles could both promote or inhibit the detonation onset. • Large distance between obstacles promotes uncontrolled self-ignition between engine cycles. • For each type of obstacles there exist optimal pitch for stable detonation onset. [ABSTRACT FROM AUTHOR]

The Cape Canaveral Barrier Island, home to the National Aeronautics and Space Administration (NASA)'s Kennedy Space Center and the United States (U.S.) Space Force's Cape Canaveral Space Force Station, is situated in a unique ecological transition zone that supports diverse wildlife. This study evaluates the recent changes in vegetation cover (2016–2023) and dune elevation (2007–2017) within the Cape Canaveral Barrier Island using high-resolution optical satellite and light detection and ranging (LiDAR) data. The study period was chosen to depict the time period of a recent increase in rocket launches. The study objectives include assessing changes in vegetation communities, identifying detectable impacts of liquid propellant launches on nearby vegetation, and evaluating dune elevation and tide level shifts near launchpads. The results indicate vegetation cover changes, including mangrove expansion in wetland areas and the conversion of coastal strands to denser scrubs and hardwood forests, which were likely influenced by mild winters and fire management. While detectable impacts of rocket launches on nearby vegetation were observed, they were less severe than those caused by solid rocket motors. Compounding challenges, such as rising tide levels, beach erosion, and wetland loss, potentially threaten the resilience of launch operations and the surrounding habitats. The volume and scale of launches continue to increase, and a balance between space exploration and ecological conservation is required in this biodiverse region. This study focuses on the assessment of barrier islands' shorelines. [ABSTRACT FROM AUTHOR]

This article presents observational results of the vertical structural evolution of ionospheric holes during two rocket launches. A combination of observations from the newly built Sanya incoherent scatter radar (SYISR) and Global Navigation Satellite System networks was employed. The vertical structural evolution of two rocket‐induced ionospheric holes over the SYISR could be divided into three stages. Firstly, 10–11 min after launch, the holes initially appeared in the topside ionosphere. Then, the holes expanded rapidly toward higher and lower altitudes. At ∼30 min after launch, the holes extended to an altitudinal range of ∼200 km to over 700 km. The maximum depletion altitude was 425 km for the afternoon event and 283 km for the midnight event. Finally, the holes recovered slowly, with faster recovery at higher altitudes. Our work contributes to further understanding the vertical structural evolutionary mechanisms of the ionospheric holes and relevant ionospheric processes. Plain Language Summary: When rockets fly in the ionosphere, numerous H2O or H2 molecules in the rocket exhaust rapidly react with the O+ in the background ionosphere and produce positive ions, which then react with electrons and lead to a large electron depletion known as ionospheric holes. The vertical structure of these holes has rarely been observed before. In this study, we observed the full vertical profile and the complete vertical structural evolution of two rocket‐induced ionospheric holes, using the newly built Sanya incoherent scatter radar (SYISR), combined with the Global Navigation Satellite System networks for their horizontal features. These two ionospheric holes occurred in the afternoon and around midnight in local time, with maximum electron depletion of 15% and 83% relative to the background ionosphere, and altitudinal distribution of 255–775 km and 202–535 km over SYISR, respectively. The vertical structural evolution of the holes displays the vertical variations of ionospheric characteristics and crucial ionospheric processes like plasma transport and chemistry. Our study contributes to a deeper understanding of the dynamics process of ionospheric holes as an artificial space weather process, which is of potential significance for monitoring space objects such as rockets. Key Points: Observations of the full vertical profile of the rocket‐induced ionospheric holes were presentedThe holes first appeared in topside ionosphere and then expanded both upwards and downwards to an altitude range of ∼200–∼700 kmThe recovery of electron density is faster for the midnight hole than the daytime one and is faster at high altitude than at low altitude [ABSTRACT FROM AUTHOR]

We estimated the altitude of aurora by combining data from all‐sky cameras at multiple places which were obtained during the LAMP sounding rocket experiment in Alaska on 5 March 2022. During the launch window of the rocket, three high‐speed all‐sky cameras were operative at three stations immediately below the trajectory of the rocket: Poker Flat, Venetie and Fort Yukon. The all‐sky cameras captured all‐sky images with a temporal resolution of 100 Hz (80 Hz for the Fort Yukon case). The method of altitude determination is based on analyses of time‐series of the optical intensity obtained from the all‐sky cameras in Venetie and Poker Flat covering the downrange area of the rocket trajectory. The estimated altitude of pulsating aurora during the rocket experiment was found to be consistent with that derived from the in‐situ observation of precipitating electrons with a model of optical emission, which confirms the feasibility of deriving the emission altitude through correlation analyses using time‐series. The estimated altitude of aurora decreased after the expansion onset of the substorm and stayed slightly below 100 km during the interval of pulsating aurora in the recovery phase. In particular, prompt and brief lowering of the auroral emission, well down to around 90 km, was detected during a transition of auroral form from discrete to diffuse which occurred ∼10 min after the onset. This result implies an existence of a process causing harder electron precipitation operative soon after the start of the expansion phase of auroral substorm. Plain Language Summary: To determine the altitude of the auroras, we analyzed the brightness of the auroras over time using the images obtained during the LAMP sounding rocket experiment in Alaska on 5 March 2022. The altitude of the pulsating auroras observed during the experiment matched the altitude estimated from the direct observation of electrons precipitating into the atmosphere, using a model of optical emissions. This confirms that the method of deriving auroral height through time‐series correlation analysis is effective. The height of the auroras decreased after the substorm began and remained just below 100 km during the period of pulsating auroras in the recovery phase. Specifically, a rapid and brief decrease in auroral height to around 90 km was observed about 10 min after the substorm started, when the aurora changed from discrete to diffuse. This indicates a process that causes more intense electron precipitation shortly after the substorm expansion phase begins. Key Points: Altitude of pulsating aurora emission was estimated by using triangulation of all‐sky camera data from multiple stations in AlaskaAltitude of pulsating diffuse aurora was lower than discrete auroraDecrease of the emission altitude occurred ∼10 min after the substorm onset [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Satellite megaconstellation (SMC) missions are spurring rapid growth in rocket launches and anthropogenic re-entries. These events inject pollutants and carbon dioxide (CO2) in all atmospheric layers, affecting climate and stratospheric ozone. Quantification of these and other environmental impacts requires reliable inventories of emissions. We present a global, hourly, 3D, multi-year inventory of air pollutant emissions and CO2 from rocket launches and object re-entries spanning the inception and growth of SMCs (2020–2022). We use multiple reliable sources to compile information needed to build the inventory and conduct rigorous and innovative cross-checks and validations against launch livestreams and past studies. Our inventory accounts for rocket plume afterburning effects, applies object-specific ablation profiles to re-entering objects, and quantifies unablated mass of objects returning to Earth. We also identify all launches and objects associated with SMC missions, accounting for 37–41% of emissions of black carbon particles, carbon monoxide, and CO2 by 2022. The data are provided in formats for ease-of-use in atmospheric chemistry and climate models to inform regulation and space sustainability policies. [ABSTRACT FROM AUTHOR]

The rate of rocket launches is accelerating, driven by the rapid global development of the space industry. Rocket launches emit gases and particulates into the stratosphere, where they impact the ozone layer via radiative and chemical processes. We create a three‐dimensional per‐vehicle inventory of stratospheric emissions, accounting for flight profiles and all major fuel types in active use (solid, kerosene, cryogenic and hypergolic). In 2019, stratospheric (15–50 km) rocket launch emissions were 5.82 Gg CO2 ${\mathrm{C}\mathrm{O}}_{2}$, 6.38 Gg H2 ${\mathrm{H}}_{2}$O, 0.28 Gg black carbon, 0.22 Gg nitrogen oxides, 0.50 Gg reactive chlorine and 0.91 Gg particulate alumina. The geographic locations of launch sites are preserved in the inventory, which covers all active launch sites in 2019. We also report the emissions data from contemporary vehicles that were not launched in 2019, so that users have freedom to construct their own launch activity scenarios. A subset of the inventory—stratospheric emissions for successful launches in 2019—is freely available and formatted for direct use in global chemistry‐climate or Earth system models. Plain Language Summary: Many governments and companies have expressed bold ambitions to grow their presence in space. However, rocket launches throw out a stream of air pollutants from their burnt fuel as they pass through the stratosphere, which is where the protective ozone layer resides. Currently, launch operators do not have to measure the impacts of their activities on the ozone layer. We gather together all the publicly available information on rocket launches in 2019, from 18 active spaceports worldwide, and make some careful assumptions to convert each rocket's fuel to its burnt fuel products left in the atmosphere. We encourage modeling groups to use our inventory for studies on how rocket launches may impact the ozone layer. Key Points: We compile a comprehensive emissions inventory of all rocket launches in 2019 at 18 active spaceportsIt itemizes chemically and radiatively active species that are produced by the main rocket fuels (kerosene, cryogenic, solid and hypergolic)We discuss the inventory's uncertainties and its usage in global models to study the impacts of rocket launches on the ozone layer [ABSTRACT FROM AUTHOR]

Copyright of Aerospace Control & Application is the property of Editorial Department of Aerospace Control & Application and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There is a growing risk to aircraft in flight from collisions with debris produced by the breakup of uncontrolled rocket bodies and satellites during atmospheric reentry. On one hand, the aviation industry has grown to almost 39 million flights per year, with a 63 % increase between 2004 and 2019. On the other hand, the number of successful rocket launches more than doubled between 2015 and 2023, from 87 to 212, respectively. During those 212 launches in 2023, 128 rocket bodies were abandoned in orbit, left to reenter uncontrollably. Such uncontrolled space object reentries are hard to predict, making mitigation measures difficult. In November 2022, a reentering Long March 5B rocket caused the closure of airspace over Europe, delaying 645 flights and having a plausible economic impact of millions of Euros. There are international and domestic laws that might enable the recovery of economic losses resulting from uncontrolled reentries, but such losses should not be allowed to occur in the first place. Instead of leaving the location of a reentry to chance, controlled reentries can be achieved with existing technologies and mission designs, directing reentries away from areas of high aircraft traffic. Moving to a controlled reentry regime would create a cost to space operators – but that cost is currently being externalized to the aviation industry. Multilateral solutions to create a controlled reentry regime should be pursued, as recommended in the 2023 Montreal Recommendations on Aviation Safety and Uncontrolled Space Object Reentries, before there is a tragedy caused by an aircraft collision with debris from a rocket body or satellite. • As the number of rocket launches and commercial aircraft flights increase, the probability of a catastrophic collision between an aircraft and reentering space debris is also growing. • Technologies and mission designs exist to enable all rocket bodies to be returned to Earth in a controlled manner, eliminating the casualty risk. • From a broad economic perspective, space companies are externalizing some of their risks and costs and imposing them on the aviation industry. • States are liable for damage caused by reentering space objects and could be liable for the economic costs caused by precautionary airspace closures. • The 2023 Montreal Recommendations offer actionable steps to reduce the risk of collisions between space debris and aircraft. [ABSTRACT FROM AUTHOR]

This paper extensively reviews hybrid rocket propulsion-related activities from combustion engine designs to launch tests. Starting with a brief review of rocket propulsion development history, a comparison among the three bi-propellant rocket propulsion approaches, and hybrid rocket engine design guidelines, a very thorough review related to hybrid rocket propulsion and its applications is presented in this paper. In addition to propellant choice, engine design also affects the hybrid rocket performance and, therefore, a variety of engine designs, considering, e.g., fuel geometry, swirl injection, ignition designs, and some innovative flow-channel designs are also explored. Furthermore, many fundamental studies on increasing hybrid rocket engine performances, such as regression rate enhancement, mixing enhancement, and combustion optimization, are also reviewed. Many problems that will be encountered for practical applications are also reviewed and discussed, including the O/F ratio shift, low-frequency instability, and scale-up methods. For hybrid rocket engine applications in the future, advanced capabilities and lightweight design of the hybrid rocket engine, such as throttling capability, thrust vectoring control concept, insulation materials, 3D-printing manufacturing technologies, and flight demonstrations, are also included. Finally, some active hybrid rocket research teams and their plans for flight activities are briefly introduced. [ABSTRACT FROM AUTHOR]

On 18 November 2023, SpaceX launched the Starship, the tallest and the most powerful rocket ever built. The Super Heavy engine separated from the Starship spacecraft and exploded at 90 km of altitude, while the main core Starship continued to rise up to 149 km and exploded after ∼8 min of flight. In this work, we used data from ground‐based GNSS receivers and we analyzed total electron content (TEC) response to the Starship flight and the two explosions. For the first time, we observed large‐distance northward propagation of intensive 2,000 km V‐shaped ionospheric disturbances from the rocket trajectory. The observed perturbations, most likely, represent shock waves propagating with the cone angle of ∼14° on the North and ∼7° on the South against the flight track that corresponds to the Mach angle of the shock waves in the lower atmosphere. The Starship explosion also produced a non‐chemical depletion in the ionospheric TEC. Plain Language Summary: On 18 November 2023, SpaceX launched the Starship, the tallest and the most powerful rocket ever built. About 2 min and 40 s after the liftoff, the Super Heavy engine separated from the Starship spacecraft and exploded at an altitude of 90 km. The main core Starship continued to rise to 149 km and exploded as well. The rocket launch and explosion produced an unexpected response in the ionosphere—the ionized part of the Earth's atmosphere. The Starship flew at a velocity, exceeding the local sound speed, and generated cone‐like atmospheric shock‐acoustic waves. Most unexpectedly, the observed disturbances represented long and intensive multi‐oscillation wave structures that propagated northward, which is unusual for disturbances driven by a rocket launch. The Starship explosion also generated a large‐amplitude total electron content depletion that could have been reinforced by the impact of the spacecraft's fuel exhaust in the lower atmosphere. This study appears to be the first‐time detection of a non‐chemical ionospheric hole produced by a man‐made explosion. Key Points: The 18 November 2023 Starship flight and explosions generated large‐scale multi‐oscillation supersonic conic waves in the ionosphereThe cone angle of the V‐shaped ionospheric disturbances corresponds to the Mach angle of shock waves propagating in the lower ionosphereThe shock waves from the Starship explosion caused a depletion in total electron content (TEC) [ABSTRACT FROM AUTHOR]

Rocket technology has shown considerable progress in recent decades. In addition to peaceful use, rockets are used in the military as a means of transporting destructive charges on a target. Any information obtained, even a partial one, could be used to prevent or mitigate a missile threat. Different types of rocket engines are sources of rocket propulsion. One of the factors by which individual types of rockets differ from each other is the type of fuel used. Combustion of rocket fuel creates a flame that is a source of radiation. The article analyzes the composition of different types of solid propellants and their combustion products. It is further considered if combustion products detected via emission spectra can indicate the rocket launch and if it is possible to identify the type of rocket by assignment of emission spectra to known propellant. The recherche of multiple sources is the method used for gathering information concerning rocket propellants. The results of the recherche are the most used propellants' compositions and their combustion products. [ABSTRACT FROM AUTHOR]

Ozan Varol's book, Think Like a Rock Scientist, contends that you can "make giant leaps in work and life" by following his guidance. The rocket scientist, however, has a much easier task than a library manager because rockets follow the laws of gravity while managers must deal with the messy problems of irrational humans. Effective communication is difficult to achieve. Cognitive dissonance and subconscious behavior inhibit rational behavior. Management must account for cultural differences and the fact that culture changes continuously unlike gravity. Success of a rocket launch is easy to measure while creating a yardstick for the evaluation of a library and applying it correctly is difficult. The advantage the library manager has is that muddling through with partial success is an option that rocket scientists don't have. For rocket scientists, research and education deal with a definitive body of knowledge while library managers must learn about ambiguity and unpredictable results. [ABSTRACT FROM AUTHOR]

We investigate the collection of dust particles in the mesosphere with the MESS (MEteoric Smoke Sampler) instrument that is designed to fly on a sounding rocket. We assume that the ice particles that form in the polar mesosphere between 80 and 85 km altitude in summer contain meteoric smoke particles; and these should be collected with MESS. The instrument consists of a collection device with an opening and closure mechanism, as well as an attached conic funnel which increases the sampling area in comparison to the collection area. Dust particles are collected either directly after passing through the instrument or indirectly after colliding with and fragmenting on the funnel wall. We calculate the dust and fragment trajectories in the detector to determine the collection efficiency for different particle sizes, rocket velocities, and heights, and we find the final velocities and the temperatures of the particles. The considered design has a sampling area of 62.78 mm diameter and a collection area of 20 mm diameter. For the conditions at the rocket launch site in Andøya, Norway, we estimate the collection of meteoric smoke particles contained in the ice particles to be ∼ 10 12 –10 14 amumm-2. The estimated temperatures suggest that the composition of these smoke particles is not affected by the collection. Our calculations also show that keeping the instrument open above 85 km altitude increases the amount of small smoke particles that are directly collected. The directly collected smoke particles are heated as they decelerate, which can affect their composition. [ABSTRACT FROM AUTHOR]

Suborbital rockets that fly focal-plane cameras that need to be cooled to optimize their operation face a series of challenges around their operation. These include maintaining a high-quality vacuum and the cooling of the detectors in a controlled way. These challenges are further heightened by the requirement that no current flows through the payload systems while the rocket motors are being armed. This paper discusses the novel pumping and cooling system implemented for the 2022 launch of the Rockets for Extended-source X-ray Spectroscopy (tREXS), including the use of a magnetic umbilical to connect the vacuum foreline to the rocket skin. [ABSTRACT FROM AUTHOR]

The satellite bears complex vibration loads transmitted from the satellite-rocket interface during launch, where medium–high frequency and small amplitude vibration is highly likely to harm the satellite's internal precision instruments. Under such special conditions, the time-delay factor of the MR damper as the actuator cannot be ignored in the vibration control of the magnetorheological (MR) whole-spacecraft. To compensate actuator time-delay, and consider the system's nonlinear characteristics under medium–high frequency and small amplitude conditions, a gray prediction time-delay compensation method is proposed based on the human-simulated intelligent controller (HSIC). After verifying through simulation and experiment that actuator time-delay affects the vibration response of the MR whole-spacecraft, the HSIC based on gray prediction is designed. Then, the control effect of HSIC with or without time-delay is simulated numerically. The results reveal that after considering the time-delay factor, the resonance peak increases by 17%, and the transmissibility of the concerned particularly frequency band (40 Hz) increases by 62%, which implies a significant deterioration in the control effect. Following, to make up for the response deterioration caused by the time-delay, the HSIC based on gray prediction is used for numerical simulation. The results confirm that reasonable time-delay compensation can effectively improve the system dynamics. This study provides a reference for the practical application of the whole-spacecraft controller. [ABSTRACT FROM AUTHOR]

Current space missions to Luna and Mars are considering to use the resources, which can be found on‐site at the destination. This strategy named in‐situ resource utilization (ISRU) saves valuable pay‐load capacities during the rocket launch from the earth surface. Specifically, in mars missions it is intended to produce the necessary rocket fuel CH4 for the back‐transit to earth via water electrolysis and subsequent CO2 methanation. The present study elaborates this concept and examines the question if polymeric reactors are feasible for heterogeneously catalyzed reactions in applications beyond earth. The study aims at providing a theoretical backbone for a proof‐of‐concept. The evaluation is conducted theoretically by design considerations and adds experimental results to show the general feasibility of polymeric reactors for applicable reaction conditions. [ABSTRACT FROM AUTHOR]

The global space industry is growing rapidly, with an increasing number of annual rocket launches. Gases and particulates are emitted by rockets directly into the middle and upper atmosphere, where the protective ozone layer resides. These emissions have been shown to damage ozone – highlighting the need for proper management of the upper atmosphere environment. We summarise the emission byproducts from rocket launches and discuss their involvement in chemical and radiative processes in the stratosphere, along with potential implications for the ozone layer due to an anticipated increase in rocket launch emissions in the future. We then present a potential vision for sustainable launches, including tractable pathways for both the aerospace industry and the ozone research community. We canvass international and domestic environmental regulation to consider how existing frameworks might be applied to rocket launches. We further identify gaps in aerospace industry practice where cooperation with environmental management and atmospheric science fields could lead to best-practise outcomes. [ABSTRACT FROM AUTHOR]

In this study, a novel variable-stiffness structure (VSS) featuring temperature-dependent characteristics is introduced for the optical payload of the Jilin1-GF04X satellite, which has an image resolution of 0.3 m. The VSS, constructed from polyurethane material, was engineered to operate at room temperature (22 °C) during the rocket launch phase in order to withstand adverse dynamic conditions. Additionally, the structure was designed to function at a higher temperature (35 °C) while in orbit to improve the efficiency of microvibration isolation. The assessment of the suppression capabilities of the presented vibration isolator, as compared to the present carbon fiber structure, was conducted through an integrated analysis. Ground-based microvibration tests were subsequently carried out to evaluate the capacity of the VSS for adjusting its stiffness and damping properties. The results showed that the maximum amplitude of pixel offset reduced by 27.6% at 35 °C compared to 22 °C, confirming the efficacy of the structure. • A variable-stiffness structure (VSS) featuring temperature-dependent characteristics is proposed. • The dynamic properties of polyurethane materials are characterized using the fractional derivative constitutive equation. • The integrated model is established by the optical model, structural model, control model of the satellite and the perturbations of the flywheel. • Ground-based microvibration tests are carried out to evaluate the capacity of the VSS for adjusting its stiffness and damping properties. [ABSTRACT FROM AUTHOR]

Aircraft and rockets entered the lower stratosphere on a regular basis during World War II and have done so in increasing numbers to the present. Atmospheric testing of nuclear weapons saw radioactive isotopes in the stratosphere. Rocket launches of orbiters are projected to increase substantially in the near future. The burnup of orbiters has left signatures in the aerosol. There are proposals to attenuate incoming solar radiation by deliberate injection of artificial aerosols into the stratosphere to "geoengineer" cooling trends in surface temperature, with the aim of countering the heating effects of infrared active gases. These gases are mainly carbon dioxide from fossil burning, with additional contributions from methane, chlorofluorocarbons, nitrous oxide and the accompanying positive feedback from increasing water vapor. Residence times as a function of altitude above the tropopause are critical. The analysis of in situ data is performed using statistical multifractal techniques and combined with remotely sensed and modeled results to examine the classical radiation–photochemistry–fluid mechanics interaction that determines the composition and dynamics of the lower stratosphere. It is critical in assessing anthropogenic effects. It is argued that progress in predictive ability is driven by the continued generation of new and quantitative observations in the laboratory and the atmosphere. [ABSTRACT FROM AUTHOR]

Recently, the increasing frequency of rocket launches, especially from Florida (USA), has sparked heated discussions about the nature of the related atmospheric phenomena reported from various parts of the Caribbean. Then, there has been a surge in curiosity about signs of analogous occurrences in Cuba. It's not strange, then, that intriguing images captured by observers, who think they have witnessed a bright fireball or bolide, are being published. In this article, we present and discuss the real nature of a number of these observation. [ABSTRACT FROM AUTHOR]

Purpose: Abnormal vibrations often occur in the liquid oxygen kerosene transmission pipelines of rocket engines, which seriously threaten their safety. Improper handling can result in failed rocket launches and significant economic losses. Therefore, this paper aims to examine vibrations in transmission pipelines. Design/methodology/approach: In this study, a three-dimensional high-pressure pipeline model composed of corrugated pipes, multi-section bent pipes, and other auxiliary structures was established. The fluid–solid coupling method was used to analyse vibration characteristics of the pipeline under various external excitations. The simulation results were visualised using MATLAB, and their validity was verified via a thermal test. Findings: In this study, the vibration mechanism of a complex high-pressure pipeline was examined via a visualisation method. The results showed that the low-frequency vibration of the pipe was caused by fluid self-excited pressure pulsation, whereas the vibration of the engine system caused a high-frequency vibration of the pipeline. The excitation of external pressure pulses did not significantly affect the vibrations of the pipelines. The visualisation results indicated that the severe vibration position of the pipeline thermal test is mainly concentrated between the inlet and outlet and between the two bellows. Practical implications: The results of this study aid in understanding the causes of abnormal vibrations in rocket engine pipelines. Originality/value: The causes of different vibration frequencies in the complex pipelines of rocket engines and the propagation characteristics of external vibration excitation were obtained. [ABSTRACT FROM AUTHOR]

A custom lightweight, miniaturized, and trackable meteorological probe was launched by a model rocket into the inflow region of an EF4, long-tracked tornado south of Lawrence, Kansas, on 28 May 2019 and sampled tornado core flow. The rocket reached apogee at 439 m a.g.l., releasing the "pseudo-Lagrangian drifter" by parachute directly into the tornado vortex. The probe reached a three-dimensional (3D) speed of 85.1 m s -1 in the first revolution around the tornado, measured an altitude-corrected pressure deficit of - 113.5 hPa at 475 m a.s.l., and sampled a tornadic updraft speed of 65.0 m s -1. The probe then transitioned to an environment exhibiting a more tilted ascent above an altitude of 4300 m a.s.l. at speeds up to 84.0 m s -1 to a maximum altitude of 11 914 m a.s.l. 1 Hz pressure, temperature, relative humidity, GPS, acceleration, gyroscope, and magnetometer data for the flight were transmitted in real time to a ground station until 10 680 m a.s.l. and the probe landed 51 km northeast of the launch position. The probe was recovered without damage, which is attributed to the pseudo-Lagrangian drifter design, and then higher-resolution and complete 10 Hz data were downloaded for the flight. This novel deployment method and design facilitate data collection in real time from within tornadoes, the mesocyclone, and downdraft without requiring the probes to be recovered or for researchers to enter the circulation to deploy equipment. [ABSTRACT FROM AUTHOR]

The commercial space launch sector is currently undergoing a significant shift, with increasing competition and demand for launch services, as well as growing concerns about the environmental impact of rocket launches. To address these challenges, within the New Space Portugal project scope, a multidisciplinary framework for designing and optimizing new launch vehicles is proposed. Creating a more resilient and responsible space industry can be achieved by combining technological innovation and environmental sustainability, as emphasized by the framework. The main scope of the framework was to couple all the disciplines relevant to the space vehicle design in a modular way. Significant emphasis was placed on the infusion of ecodesign principles, including Life Cycle Assessment (LCA) considerations. Optimization techniques were employed to enhance the design and help designers conduct trade-off studies. In general, this multidisciplinary framework aims to provide a comprehensive approach to designing next-generation launch vehicles that meet the demands of a rapidly changing market while also minimizing their environmental impact. A methodology that leverages the strengths of both genetic and gradient-based algorithms is employed for optimizations with the objectives of maximizing the apogee altitude and minimizing the Global Warming Potential (GWP). Despite only being tested at the moment for sounding rockets, the framework has demonstrated promising results. It has illuminated the potential of this approach, leading to the identification of three optimal designs: one for maximizing the apogee, another for minimizing GWP, and a compromise design that strikes a balance between the two objectives. The outcomes yielded a maximum apogee of 6.41 km, a minimum GWP of 9.06 kg CO 2 e q , and a balanced compromise design featuring an apogee of 5.75 km and a GWP of 25.64 kg CO 2 e q . [ABSTRACT FROM AUTHOR]

This research investigated fatigue crack propagation on the lower surface of rocket deflector troughs in offshore rocket launch platforms. Initially, a numerical model of an offshore rocket launch platform was established using ABAQUS based on the Extended Finite Element Method (XFEM). Subsequently, two variable parameters—the initial crack length and initial tilt angle—were introduced. This research systematically analysed the impact of these parameters on the fatigue crack propagation patterns in both the maximum stress and maximum deformation regions of the deflector channels under the combined conditions of high temperature and impact. Finally, the research indicated that the propagation length of surface cracks in the deflector trough exhibited an initial increase followed by a decrease with the rise in the pre-set inclination angle. Notably, the stable propagation rate of the crack in the region of maximum deformation surpassed that observed in the region of maximum stress. Through meticulous comparative analysis, it was evident that temperature loading significantly exacerbated the initiation and propagation of cracks, particularly in the upper region of the deflector channel's lower surface. [ABSTRACT FROM AUTHOR]

The power system, as a core component of a launch vehicle, has a crucial impact on the reliability and safety of a rocket launch. Due to the limited measurement information inside the engine, it is often challenging to realize fast and accurate anomaly detection. For this reason, this paper introduces the rocket flight state data to expand the information source for anomaly detection. However, engine measurement and rocket flight state information have different data distribution characteristics. To find the optimal data fusion scheme for anomaly detection, a data set information fusion algorithm based on convex optimization is proposed, which solves the optimal fusion parameter using the convex quadratic programming problem and then adopts the adaptive CUSUM algorithm to realize the fast and accurate anomaly detection of engine faults. Numerical simulation tests show that the algorithm proposed in this paper has a higher detection accuracy and lower detection time than the traditional algorithm. [ABSTRACT FROM AUTHOR]