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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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

As an important means of in situ detection in near space, meteorological rockets can provide a high-precision distribution analysis of atmospheric elements. However, there are currently few studies on the principles of meteorological-rocket detection and the application of rocket-sounding data. The purpose of this paper is to fill this gap by providing a detailed introduction to the detection principle of a meteorological rocket launched in the East China Sea in November 2022. Moreover, empirical models, satellite data, and reanalysis data were selected for comparison and verification with the rocket-sounding data. Furthermore, the accuracy of these widely used datasets was studied based on the rocket-sounding data in the near space over the East China Sea. Additionally, gravity-wave power–frequency spectra were extracted using the maximum entropy method from both the rocket-sounding data and the remote-sensing data. Furthermore, the relationship between gravity waves and Kelvin–Helmholtz instability (KHI) was investigated by analyzing the gravity-wave energy and the Richardson number. The research findings indicate that among the remote-sensing data describing the atmospheric environment over the launch site, the COSMIC occultation data is more accurate compared with the SABER data. The wind-field distribution derived from rocket detection is consistent with the Modern-Era Retrospective analysis for Research and Applications (MERRA) reanalysis data, while also providing a more detailed description of the wind field. The main wavelengths of gravity waves extracted from rocket-sounding data are consistently smaller than those obtained from satellite remote-sensing data, indicating that rocket sounding is capable of capturing more intricate structures of gravity waves. The good correspondence between the peaks of gravity-wave energy and the regions where KHI occurs indicates that there is a strong interaction between gravity waves and KHI in the middle atmosphere. [ABSTRACT FROM AUTHOR]

This article proposes a new three-dimensional (3D) guidance algorithm for a two-stage solid rocket-powered launch vehicle in the ascent phase. The method consists of a longitudinal and lateral cooperative online trajectory generation method and a model predictive control (MPC) based tracking method. First, we introduced a new variable, named lateral displacement distance, to describe lateral motion. After decoupling the 3D dynamics into the longitudinal and lateral movements, the lateral distance was calculated by minimum order polynomials, as well as the altitude in the longitudinal plane. The multiple constraints were satisfied accordingly. This new representation transforms the online trajectory generation problem into a single-parameter root-finding problem, which is solved online by Newton's method. Second, the traditional energy management method, which usually works in the last phase of multistage solid rockets, was extended to all stages. A proportion was put forward to allocate the energy management demand to the two stages of solid rockets. This strategy can enlarge the energy management capacity of solid rockets. Third, the MPC method was adopted to obtain the tracking guidance law to lessen the effect of uncertain parameters. The subsequent stability analysis shows that the MPC-based tracking controller is closed-loop stable and can handle the constraints and parameter uncertainties simultaneously. Finally, the effectiveness and robustness were verified by validating a two-stage solid rocket's ascent phase flight under aerodynamic uncertainties and initial state deviations. In comparison to the existing energy management method, the incorporation of the sideslip angle design in this study renders solid rockets more capable at energy management. The proposed algorithm can accurately steer the rocket vehicle to the transition window. [ABSTRACT FROM AUTHOR]

We have identified for the first time an energy‐time dispersion of precipitating electron flux in a pulsating aurora patch, ranging from 6.7 to 580 keV, through simultaneous in‐situ observations of sub‐relativistic electrons of microburst precipitations and lower‐energy electrons using the Loss through Auroral Microburst Pulsation sounding rocket launched from the Poker Flat Research Range in Alaska. Our observations reveal that precipitating electrons with energies of 180–320 keV were observed first, followed by 250–580 keV electrons 0–30 ms later, and finally, after 500–1,000 ms, 6.7–14.6 keV electrons were observed. The identified energy‐time dispersion is consistent with the theoretical estimation that the relativistic electron microbursts are a high‐energy tail of pulsating aurora electrons, which are caused by chorus waves propagating along the field line. Plain Language Summary: Microbursts, which are bursts of high energy electrons, and pulsating auroras, which periodically blink and caused by the precipitation of low energy electrons, are observed in the Earth's polar ionosphere. The detection time differences of the electrons associated with microbursts and pulsating auroras were detected by a sounding rocket. A possible mechanism for the generation of these precipitations is the interaction of electrons with a particular type of wave, known as "chorus," which propagates along geomagnetic lines. The observed energy‐time dispersion of the precipitating electrons is quantitatively consistent with theories of electron precipitation based on this interaction. Key Points: A sounding rocket observed simultaneously precipitating sub‐relativistic electron microbursts and pulsating auroral electrons250–580 keV electron precipitations were detected 0–30 ms after 180–320 keV electron precipitations in a single auroral patchThe energy dispersion of observed electrons is consistent with the theory that they are due to chorus waves propagating to higher latitudes [ABSTRACT FROM AUTHOR]

The emerging arena of space exploration has created opportunities to study cancer cell biology in the environments of microgravity and hypergravity. Studying cellular behavior in altered gravity conditions has allowed researchers to make observations of cell function that would otherwise remain unnoticed. The patient-derived QNS108 brain tumor initiating cell line (BTIC), isolated from glioblastoma (GBM) tissue, was launched on a suborbital, parabolic rocket flight conducted by EXOS Aerospace Systems & Technologies. All biologicals and appropriate ground controls were secured post-launch and transported back to our research facility. Cells from the rocket-flight and ground-based controls were isolated from the culture containers and expanded on adherent flasks for two weeks. In vitro migration, proliferation, and stemness assays were performed. Following cell expansion, male nude mice were intracranially injected with either ground-control (GC) or rocket-flight (RF) exposed cells to assess tumorigenic capacity (n = 5 per group). Patient-derived QNS108 BTICs exposed to RF displayed more aggressive tumor growth than the GC cells in vitro and in vivo. RF cells showed significantly higher migration (p < 0.0000) and stemness profiles (p < 0.01) when compared to GC cells. Further, RF cells, when implanted in vivo in the brain of rodents had larger tumor-associated cystic growth areas (p = 0.00029) and decreased survival (p = 0.0172) as compared to those animals that had GC cells implanted. [ABSTRACT FROM AUTHOR]

One of the crucial branches of activity at the Łukasiewicz Research Network—Institute of Aviation is developing a suborbital rocket vehicle capable of launching small payloads beyond the Earth's atmosphere, reaching over 100 km in altitude. Ensuring safety is a primary concern, particularly given the finite flight zone and impact area. Crucial to safety analysis is the wind profile, especially in the very first seconds of a flight, when rocket velocity is of the same order as the wind speed. Traditional near-ground wind data sources, ranging from wind towers to numerical models of the atmosphere, have limitations. Wind towers are costly and unfeasible at many test ranges used for launches, while numerical modeling may not reflect the specific ground profile near the launcher due to their large cell size (2 to +10 km). Meteorological balloons are not favorable for such measurements as they aim to provide the launch operator with a wind profile at high altitudes, and are launched only 1–2 times per flight attempt. Our study sought to prototype a wind measurement system designed to acquire near-ground wind profile data. It focuses on measuring wind direction and speed at near-ground altitudes with higher flight frequency, offering data on demand shortly before launch to help ensure safety. This atmosphere sounding system consists of an Unmanned Aerial Vehicle (UAV) equipped with an onboard ultrasonic wind sensor. Some reports in the literature have discussed the possibility of using UAV-borne anemometers, but the topic of measurement errors introduced by placing the anemometer onboard an UAV remains under studied. Limited research in this area underlines the need for experimental validation of design choices–for specific types of UAVs, anemometers, and mounting. This paper presents a literature review, a detailed overview of the prototyped system, and flight test results in both natural (outdoor) and controlled (indoor, no wind) conditions. Data from the UAV system's anemometer was benchmarked against a stationary reference weather station, in order to examine the influence of the UAV's rotor on the anemometer readings. Our findings show a wind speed Root Mean Square Error (RMSE) of 5 m/s and a directional RMSE of below 5.3° (both averaged for 1 min). The results were also compared with similar UAV-based wind measurements. The prototyped system was successfully used in a suborbital rocket launch campaign, thus demonstrating the feasibility of integrating UAVs with dedicated sensors for performing regular meteorological measurements in automatic mode. [ABSTRACT FROM AUTHOR]

Space Concordia is launching the biggest student built Canadian rocket with the aim of passing the Karman Line. Launching from Churchill, Manitoba, a former military airbase used in the 1950s for suborbital sounding rocket launches, Space Concordia's ambition is to reinstate the zone as a launch site. Being the first launch out of Churchill in decades, safety is mandatory and must follow the established safety protocols and regulations for suborbital launch vehicles. Space Concordia must structure its own guidelines and requirements leveraging expertise from the Federal Aviation Administration and various agreements with local authorities. To ensure safety, the Flight Performance team runs wind weighting optimization algorithms using Astos, a 6 degree of freedom flight simulation software utilizing wind data from a weather balloon. Launch simulations in Astos are done using historical wind data through a combination of Python and A programming and numeric computing software (MATLAB) analysis scripts. Casualty expectation plays a significant role in the launch safety analysis since the launch site is situated next to a national park and multiple small communities. The probability of casualty is calculated to be 2.61E−8, which is smaller than the 30E-6 Federal Aviation Administration requirement. Establishing a strict set of guidelines while building a rocket creates many difficulties in terms of both design and regulations, however they permit a clearer structure for future launches made by Space Concordia as well as augment predefined understanding of the weather effect on Churchill suborbital rocket launches. • Launch of a Liquid Sounding Rocket. • Wind weighting optimization using Astos Solutions. • Establishment of unguided sounding rockets launch requirements. • Influence of weather conditions on the trajectory of an unguided launch vehicle. • Development of prediction models for the trajectory of an unguided launch vehicle. [ABSTRACT FROM AUTHOR]

In this paper, the cooling effect of seawater spraying on the offshore launching platform used by the CZ-8X rocket at different takeoff heights is studied. The rocket plume model using the realizable k- ε turbulence model is established, which is based on the three-dimensional Navier-Stokes equations. The injected seawater for cooling the deck surface is described by the Eulerian dispersed phase (EDP) model. The numerical results are compared with the experimental data in the literature to verify the validity and accuracy of the numerical model. The coupled flow field of the CZ-8X rocket plume and seawater at different takeoff heights and different spray velocities are simulated. The results show that the thermal environment on the deck surface of the platform is the worst when the takeoff height reaches 30 m. The seawater spraying velocity shall be moderate before the takeoff height reaches 30 m. A low spraying velocity will lead to poor cooling effect on deck surface, and a high spraying velocity could lead to increased diffusion of plume flow in non-spraying direction. After the takeoff height rises to 40 m, a low water spraying velocity makes the injection position of seawater far away from the jet core area, and the seawater evaporation rate is low, which is conducive to the accumulation of seawater layer on the deck surface. The cooling effect of thermal barrier layer is very obvious. The research shows that when the rocket is launched at sea, the launch platform can be cooled by pumping and spraying seawater, and the water spraying rate can be adjusted appropriately according to the takeoff height to achieve the best cooling effect. [ABSTRACT FROM AUTHOR]

Growth models with resources and environmental externalities typically assume that planet Earth is a closed economy. However, private firms like Blue Origin and SpaceX have reduced the cost of rocket launches by a factor of 20 over the last decade. What if these costs continue to decline, making mining from asteroids or the moon feasible? What would be the implications for economic growth and the environment? This paper provides stylized facts about cost trends, geology, and the environmental impact of mining on Earth and potentially in Space. We extend a neoclassical growth model to investigate the transition from mining on Earth to Space. We find that such a transition could potentially allow for continued growth of metal use, while limiting environmental and social costs on Earth. Acknowledging the high uncertainty around the topic, our paper provides a starting point for research on how Space mining could contribute to sustainable growth on Earth. [ABSTRACT FROM AUTHOR]

The dissonant development of positive and negative lightning leaders is a central question in atmospheric electricity. It is also the likely root cause of other reported asymmetries between positive and negative lightning flashes, including the ones regarding: stroke multiplicity, recoil activity, leader velocities, and emission of energetic radiation. In an effort to contrast lightning leaders of different polarities, we highlight the staggering differences between two rocket‐triggered lightning flashes. The flash beginning with upward positive leaders exhibits an initial continuous current stage followed by multiple sequences of dart leaders and return strokes. On the other, in its opposite‐polarity counterpart, the upward development of negative leaders is by itself the entire flash. As a result, the flash with negative leaders is faster, briefer, transfers less charge to the ground, has lower currents, and smaller spatial extent. We conclude by presenting a discussion on the three fundamental leader propagation modes. Plain Language Summary: Lightning flashes that carry positive and negative charges are completely different. In this article, we report on lightning triggered by launching a rocket tethered to the ground toward an electrified cloud. The staggering differences between positive and negative flashes are exposed by a three‐dimensional radio location system and by the current transferred to ground via the trailing wire. Key Points: Triggered flashes with positive and negative leaders are contrastingly different with the latter being faster, briefer, and more compactThe channel behind triggered positive leaders decays engendering dart leaders and return strokes, which is unparalleled in the negative caseAverage conductivity is higher in the negative leader channel despite the lack of return strokes and the lower charge transferred to ground [ABSTRACT FROM AUTHOR]

To predict the long-term storage capability (LTSC) of composite directors for multiple launch rocket system (MLRS) in the actual environment, a creep constitutive model was established in a three-dimensional nonlinear form, which considered the moisture effect by introducing a moisture shift factor that related to moisture absorption (MA) into the nonlinear Schapery equation. The constitutive model in integral form was transformed into the incremental-iterative form to realize the numerical finite element solution. Quasi-static experiments and short-term creep-recovery tests for E-glass/6509 epoxy resin laminate were performed to obtain the moisture and stress dependent parameters. A coupled numerical model in multi-physical field of moisture diffusion-nonlinear creep was established, and the MA process and creep deformation of composite directors during storage were predicted. The influence law of creep strain on rocket launching was further investigated by establishing the coupled rocket-directors launching dynamics model. The results show that the water diffuses to the inner surface of directors after storage one year in the environment of temperature of 30°C and relative humidity of 70% RH, while a saturated MA state was reached after 8 years storage. Maximum residual strain (RS) in 20 directors locates between the 2nd and 3rd positioning mounting rings, whose distribution likes a saddle-shape. The residual strains of the middle position in the upper and lower rows are the greatest, with a value of 0.38 mm; and the middle position in the left and right columns are the smallest, with a value of 0.33 mm. The creep strain increases the angular displacement and rate in the pitch and yaw directions of the rocket axis. [ABSTRACT FROM AUTHOR]

While our modern world is today unimaginable without space, the space landscape is changing fast. For long near space has been a vast resource to exploit with few limits. This situation is however changing since in reality orbital resources are scarce and are threatened by the growth of the space debris population. Space debris is one of the human-made problems along the climate crisis, air pollution or ocean plastic pollution among other environmental issues that keep growing despite the awareness of their dangers to societies and our economies. The debris population has been growing drastically over the years due to the increase of rockets and satellites launches, accidental collisions of space objects, as well as deliberate Anti-Satellite Tests (ASAT s). Addressing appropriately the space debris issues is today an unescapable necessity to allow realising the deployments of the planned space constellations in a responsible manner. This would also provide stability and continuity to space activities so that the public and commercial sectors can continue to innovate and invest in new ventures that continue building a robust space economy. This paper discusses the direct and collateral challenges of space debris on the space economy and presents technological and political actions needed to face this growing problem for the present and future generations. [ABSTRACT FROM AUTHOR]

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The safety zone around the flight path of a rocket is determined by the fall of debris in the case of an accidental explosion or commanded termination. The trajectory of a tumbling body in a vertical plane is determined by specifying the velocity, flight path angle and angle of attack as functions of time. This involves the lift, drag and pitching moment coefficients as functions of the angle of attack over a full circle—0 to 360 degrees—to account for the tumbling motion. The problem is reduced to a third-order non-linear differential equation for the angle of attack by using the approximation of free fall coordinates. The analytical and numerical solutions show that two types of tumbling fall are possible, one with rotation and the other with oscillation. The tumbling trajectories are plotted and discussed for a variety of initial conditions, mass and aerodynamic properties of the tumbling body. [ABSTRACT FROM AUTHOR]

Copyright of Risk, Hazards & Crisis in Public Policy is the property of Wiley-Blackwell 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.)

For much of their existence, the environmental benefits of artificial satellites, particularly through provision of remotely sensed data, seem likely to have greatly exceeded their environmental costs. With dramatic current and projected growth in the number of Earth‐observation and other satellites in low Earth orbit, this trade‐off now needs to be considered more carefully. Here we highlight the range of environmental impacts of satellite technology, taking a life‐cycle approach to evaluate impacts from manufacture, through launch, to burn‐up during de‐orbiting. These include the use of renewable and nonrenewable resources (including those associated with the transmission, long‐term storage, and distribution of data), atmospheric consequences of rocket launches and satellite de‐orbiting, and impacts of a changing nighttime sky on humans and other organisms. Initial estimations of the scale of some impacts are sufficient to underscore the need for more detailed investigations and to identify potential means by which impacts can be reduced and mitigated. [ABSTRACT FROM AUTHOR]

A comprehensive investigation is undertaken to discern the structure of momentum flux, turbulent kinetic energy, and scalar fluxes like heat, CO 2 , and H 2 O in the atmospheric surface layer (ASL) at the Thumba Equatorial Rocket Launching Station—a coastal station on the west coast of southern peninsular India. The vertical transport, transfer efficiency, and dissimilarity between flux transport are studied as a function of stability using data collected over 1 year. The transfer efficiency for heat fluxes and momentum exhibits a strong dependence on stability (ζ ). However, the transfer efficiency of passive scalars CO 2 and H 2 O displays no apparent dependence on ζ . The correlation between fluxes and squared coherence estimates is evaluated to study the dissimilarity between flux transport. The correlation is strongest among momentum and heat fluxes and between CO 2 and H 2 O fluxes and shows a dependence on the prevailing stability conditions. However, the influence of stability is not evident for the various other combinations. The momentum and heat flux transport is dissimilar for unstable conditions, and it becomes similar during the transition from unstable to near-neutral conditions. The quadrant analysis is employed to study the contribution of different fluid motions to the aforementioned turbulent fluxes. Except for CO 2 and H 2 O fluxes, where all the quadrants have an equal contribution, ejections and sweeps are the dominating contributors for momentum and heat fluxes. The stability conditions greatly determine the ejection-sweep balance for heat flux, while some changes in duration and impact fraction are also detectable for momentum flux. Furthermore, contour maps of joint-probability function (JPDF) of vertical velocity fluctuations ( w ′ ) with streamwise velocity fluctuation ( u ′ ), temperature fluctuation ( T ′ ), and scalar fluctuations, respectively, are also presented. The dominance of the ejection and sweep cycles for turbulent fluxes provide evidence for the presence and importance of coherent structures in ASL. [ABSTRACT FROM AUTHOR]

Multi-stage launch vehicles are currently the primary tool for humans to reach extraterrestrial space. The technology of recovering and reusing rockets can effectively shorten rocket launch cycles and reduce space launch costs. With the development of deep representation learning, reinforcement learning (RL) has become a robust learning framework capable of learning complex policies in high-dimensional environments. In this paper, a deep reinforcement learning-based reusable rocket landing control method is proposed. The mathematical process of reusable rocket landing is modelled by considering the aerodynamic drag, thrust, gravitational force, and Earth's rotation during the landing process. A reward function is designed according to the rewards and penalties derived from mission accomplishment, terminal constraints, and landing performance. Based on this, the Softmax double deep deterministic policy gradient (SD3) deep RL method is applied to build a robust reusable rocket landing control method. In the constructed simulation environment, the proposed method can achieve convergent and robust control results, proving the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]