Space Vehicle Launch Research Articles

Design of a locally resonant system to reduce noise inside the payload fairing of a launcher during the lift-off

The high sound pressure exerted on the payload during the launch of space vehicles can jeopardize its structural integrity. Given space and weight restrictions, designing fairing noise protection systems is not easy and the number of alternatives is limited, especially for small launchers. This work proposes the design of an acoustic protection based on an simultaneous increase of insulation and absorption in the system tailored to the payload fairing of a space launcher. To this end, the use of a panel made of Helmholtz resonators is investigated. The panel presents a deep subwavelength thickness, as well as a highly efficient acoustic protection (90% of absorption and 13 dB of Transmission Loss) over the frequency range of interest. The panel is designed by considering a reciprocal and non mirror symmetric transmission problem and the acoustic incidence from both sides of the panel. A high Transmission Loss in the frequency range of interest is then obtained when considering an incidence coming from the outside of the payload fairing, whereas the quasi-perfect absorption of acoustic waves is observed in the case where the incidence comes from the inside of the fairing. The panels are subsequently prototyped and their performance is experimentally evaluated. Measurements are correlated and discussed in view of the theoretical and numerical predictions. This mitigation approach sets a new trajectory for innovative noise reduction in small-scale space launchers.

Flow and Aeroacoustic Characteristics of Underexpanded Supersonic Jets Exhausting from a Conical Converging Nozzle

Ensuring the safety of space flights and solving the problems of reducing acoustic loads during the launch of space vehicles requires not only the development of new technical systems for launch complexes, but also methods for the numerical simulation of fluid and aeroacoustic fields generated by supersonic jets. The growing regulations for space vehicle noise also explain the interest in developing models and techniques that anticipate flow and the aeroacoustic characteristics of supersonic jets. Together with integral techniques for computing far-field noise, development of relevant mathematical models and implementation of numerical tools, the concepts of computational fluid dynamics (CFD) and computational aeroacoustics (CAA) are covered. The noise generated by a supersonic underexpanded jet is used to illustrate the capabilities of current numerical modelling and simulation tools. The jet structure, flow properties, and aeroacoustic quantities are affected by the nozzle pressure ratio. The outcomes of numerical simulation are contrasted with existing experimental and computational data. The available numerical modelling and simulation tools facilitate the development of novel computational methods and methodologies for challenges in CFD and CAA, in addition to solving research and engineering problems.

The Future of the Law on the Moon

Outer space is rapidly becoming the domain for industrial-scale private-sector innovation and entrepreneurship. By developing and maturing the unprecedented technology for vertical landing and partial reuse orbital-class rockets, Space Exploration Technologies Corporation (SpaceX) has reduced the cost of access to orbital space by a staggering factor of magnitude, i.e., to one-tenth the previous rate. SpaceX is now on the cusp of launching its next-generation launch system called Starship to orbit. Starship is designed to be fully and rapidly reusable (land, refuel, and fly like airplanes) and expected to decrease the cost of access to orbital space to a level comparable to air travel— whereby private-sector industry in outer space would become economically viable. SpaceX is developing Starship at a breakneck speed, planning for an orbital launch in April 2023. Starship would function as the Earth–Moon transportation infrastructure for private-sector lunar activities like tourism, hospitality, mining, research, entertainment, construction, health, agriculture, and manufacturing. And the Moon is just three days away. Assuming a large fleet of reusable Starships would take flight to the Moon in the coming years, lawyers have an urgent and exciting task of laying the legal groundwork on the Moon for the complex modern governance and economy. But the legal discussion on the future of the law of the Moon has not even begun. This Article aims to fix this lacuna by first presenting specific and realistic parameters for discussion: namely, SpaceX would likely give the United States the exclusive, economic, and scalable access to the Moon within a few years, enabling a sizable private sector presence (persons and property) on the Moon engaged in commercial ventures within a decade. A commercialized Moon would require the United States to assert legislative jurisdiction (U.S. federal law taking effect), exercise adjudicatory jurisdiction (personal jurisdiction over persons and property and subject matter jurisdiction regarding controversies that arise), and install a governing body physically on the Moon. After a brief introduction of today’s space industry, Part II surveys the history of U.S. regulation of commercial space exploration. Part III summarizes the current regulatory framework that governs only the launch and landing of space vehicles on Earth. Part IV is a more detailed analysis of the space industry and the economics of space exploration. Part V shows the possibility of domestic jurisdiction in outer space, delimited by binding international space treaties and customs. Part VI focuses on two treaties as providing the foundation of domestic jurisdiction in space. As an example of the governing body, in Part VII, this Article introduces the U.S. Lunar Court and sketches the legal contours of this new adjudicatory body. The Appendix shows detailed calculations of Starship’s expected capabilities and economics based on Falcon 9’s historical data.

Deflector shape impact on aero-acoustic noise generation and propagation

The vibroacoustic loading generated during the launch of space vehicles can cause the failure of electronic and mechanical components. Therefore, the prediction and mitigation of these vibroacoustic levels are crucial to improve the reliability of launchers and payload comfort. Because a properly designed flame deflector has the power to significantly reduce the acoustic pressure level, the aeroacoustics characteristics of diverse types of flame deflectors must be understood. Three different deflector geometries have been analysed: a wedge-type deflector, which is currently used on the VEGA rocket launch pad, a 30-degree inclined deflector, since new studies highlight its noise reduction capacity, and a flat deflector, since the impact on a flat plate is the simplest case of reflection. The sound generation and propagation in the launch platform full domain for each case were studied using dedicated computational fluid dynamics in BSC MareNostrum. To assess noise generation, the main shock waves were identified, and the evolution of the generated sound pressure was assessed. Moreover, the sound pressure levels at the fairing surface have been studied. Further research is focused right now on the use of an efficient solver running on graphics processing units that is capable of computing large-scale turbulence.

Assessing the impact of ground reflection on measurement of the overall sound power level and acoustic radiation efficiency of rocket launches

Determining the sound power levels of a rocket is the first step in characterizing its radiation efficiency. Because the sound radiation from a launch vehicle is anisotropic, well-calibrated ground measurement stations are used, along with trajectory data, to obtain sound power. Historically, the effect of ground reflections appears to largely have been neglected in the literature, despite the potential to inflate OAPWLs and therefore radiation efficiency. This study investigates the likely effect of a finite-impedance ground on spectra, overall sound pressure levels, and power levels. The single-parameter ground reflection model by Embleton et al. [J. Acoust. Soc. Am. 74, 1239–1244 (1983)] is used to obtain an estimate for change in OASPL for a model spectrum based on space vehicle launches. When the correction is applied to the OAPWL it produces in a nearly 3dB reduction in level and reducing the efficiency by a factor of 2. This indicates the possibility that the 0.5% radiation power efficiency assumed for rockets in the past is too high.

Numerical study of unmanned aerial vehicle (UAV) in dry microburst environment using large eddy simulation (LES) model

PurposeIn a microburst wind, the profiles and characteristics are significantly different from those of normal boundary layer winds. The objective of this work is to study the microburst effect on the performance of aircraft for providing guidelines to frame escape strategies.Design/methodology/approachLarge eddy simulation model is used to study the effect of microburst by simulating the actual physical process of microburst-generated downdraft environment over the unmanned aerial vehicle. In this work, an attempt has been made to simulate the dry microburst (microburst not accompanied by rain) numerically using the impinging jet model to explore the effect of microburst at 12° angle of attack for flight take-off condition with a Mach number 0.04.FindingsThe numerical results revealed the aerodynamic performance loss of an aircraft in the microburst-generated downdraft during take-off condition quantitatively. This could be a more valuable information to the aviation industry. The authors believe that the results shown in this paper will be useful for the designers of aircraft. This will also help train the pilots to control the airplanes in a microburst environment.Practical implicationsSevere thunderstorms are significant weather phenomena that have a significant impact on various facets of national activity, including civil and defence operations, specifically aviation, space vehicle launch and agriculture, in addition to their potential to cause damage to life and property.Originality/valueThe maximum percentage of pressure increases on the upper surface of the aircraft between 2 and 7 s is 99.86% under the microburst-generated downdraft condition. The flight escape maneuver could be initiated, before increasing the pressure on the upper surface of the aircraft. The aircraft flies with high airspeed through the microburst environment, where the microburst-generated downdraft is most severe.

Infrasound from orbital space vehicle launches

Launches of medium and heavy-lift space vehicles produce high-amplitude, broadband noise environments with significant infrasound. Measurements taken at Vandenberg Space Force Base during Falcon 9 and Delta IV Heavy launches allow for a comparison of infrasound between rockets and environments. For the Falcon 9, low surface wind and high signal-to-noise ratios allowed for the observation of infrasound all the way through main engine cutoff. In contrast, the Delta IV Heavy measurements featured much higher surface winds and lower signal-to-noise ratios. However, even during the Delta IV Heavy measurement, infrasound was recorded for several minutes after liftoff. Characteristics as a function of distance and time are discussed.

Analysis of overall noise levels from space vehicle launches

A previous paper [L. T. Mathews et al., J. Acoust. Soc. Am. 146, 3043 (2019)] described acoustical measurements made of Falcon 9 space vehicle launches, as measured from various locations within a community near Vandenberg Air Force Base. This paper investigates the directivity pattern measured at one of the launches and compares it with historical and recent literature. Comparisons are made for peak directivity angle and corresponding level at that angle, directivity pattern shape, and calculated overall power level. Results are connected to relatively simple models based on a few engine parameters.

Energetic Compositions Application for the Reduction of the Environmental Pollution Because of Space Vehicle Launches

Technogeneous impact of rocket and space activities on the environment is one of the most actual problems of practical cosmonautics. This technogeneous impact is not only the pollution of near Earth space with space debris (worked-off stages of space launch vehicle (SLV)), but also the pollution of significant areas on the Earth surface with worked-off lower stages of SLV, which fall down after having accomplished their mission. In OmSTU and IPCP RAS it was suggested to apply different self-burning compositions, generating hot gases for the evaporation of the unused residues of liquid propellant in tanks of SLV. Then the mixture of the evaporated compounds together with the gaseous combustion products from gas-generating compositions is used as propellant mixture for the autonomous gas rocket engine. Such a solution would decrease considerably the level of the environment pollution and additionally it increases the energetic characteristics of SLV. For example, in the case of the second stage of SLV «Soyuz-2.1.v» it increases the total velocity by 5%. Also it is proposed to use firing the pyrotechnic compositions like (thermites) for the fairings heating up to the temperature when the fairing material can be ignited in air. It would reduce considerably the amount and the mass of the separating parts of SLV that fall to the Earth.

IMPLEMENTATION OF A SMALL SPACE VEHICLE DEVELOPMENT PROJECT AS AN ILLUSTRATION OF THE INNOVATIVE UNIVERSITY EVOLUTION

Innovative development of the national economy, that has been declared in the Conception of long-term social and economic development of the Russian Federation, has become especially important in the modern situation characterized by geopolitical challenges and threats. Russia is looking for new possibilities to strengthen its competitive position in the global economy. One of the most promising innovative development areas is space science and technologies. Space technologies of manned flights developed in Russia have always been exceptionally competitive. However, in the last decade the onset of new aerospace industries in such countries as China, India or the USA has jeopardized the Russian Federation position of the world leader in this field. In this context such new trends in space technologies as the design, manufacture and launching of small-size space vehicles may be interesting both in terms of advanced engineering and technological solutions and in terms of commercial application of innovative low-cost space products. There are already several very positive practical examples of this engineering field development that involves the adoption of the so-called three-spiral theory describing the interaction between the state, science and business. One of such examples is the Southwest State University that has accumulated an extensive experience of long-time cooperation with Roscosmos (Russian Space Agency) core engineering businesses in the area of small space vehicle design and manufacture. This is a unique experience that has no parallels in Russia or abroad. In terms of economics such integration presents a good object for the investigation of system interaction between national authorities, businesses, educational and scientific institutions. It also makes a sound basis for the successful dissemination of the know-how.

Micrometeorological Tower Observations and its Importance in Atmospheric Modelling and Space Technology

Background/Objectives: The assessment of turbulence parameters is important for understanding the heat, momentum exchange and pollutant dispersion at any given site. Methods/Analysis: Continuous micrometeorological data were collected at SRM University, Kattankulathur (12o 48’ N to 12o 49’ N; 80o 02’ E to 80o 03’ E) a sub-urban area near Chennai by a 16 m meteorological mast. Data with conventional sensors were obtained for wind, temperature, and humidity from August 2010 to March 2015. Findings: The gradient observations were analyzed to explore the atmospheric surface layer parameters and were used in atmospheric dispersion modeling. Wind and temperature data were analyzed to understand their diurnal and seasonal variations. The Inter-relationships of temperature and wind pattern were discussed and the diurnal variations of temperature and wind profile were plotted for a particular month during study period to assess the Climate pattern ofa particular study period. This study may play a vital role in atmospheric modeling and also in space vehicle launching.

Exploring the Possibilities for Improving the Performance of the Adapters used for Launching Multiple Small Space Vehicles on a Single Launch Vehicle

Background/Objectives: The research is aimed at determining the ways to improve the effectiveness of reconfigurable and extendable multipurpose adapters for multiple launch of small space vehicles by a launch vehicle. Methods: The structural design method is selected for studying design and constructive shape of the SSV adapters. The structural approach was used to define the principle for optimization of adapters of various constructive schemes, excluding modifications of launch vehicle used for multiple launches and enabling to extend and reduce adapter configuration with respect to a universal basic structure used for all tasks for SSV launch to be solved. Findings: To obtain quasi-optimal design and engineering parameters for the entire target set of tasks solved by the adapter, based on the structural approach we have considered design schemes of multi-purpose adapters for multiple and concurrent launching of SSVs of rod, shell, beam and platform types with side and end attachment configuration, the schemes with shock absorbers mounted in the places of adapters and MCAs installation, and scheme configuration combining adapter + small upper stage. The base and extension structures have been determined to form multi-purpose adapter with flexible and extensible design. As a result of the proposed technical solutions, weight of the adapter is reduced by 30%, configuration density is increased by 30-40 %, the number of the launched SSVs is increased, the fairing length and weight is reduced by 50%, root-mean-square amplitudes of accidental vibration decreased by 2.5-3 times, level of shock loads during SSV separation decreases by 6-10 dB, provision is made for shockless separation of SSV required lateral alignment of LV, cost reduction for ground and flight tests. Application/Improvements: Further improvement of the multi-purpose adapters is connected with the co-design of “Adapter + SSV” system, taking into account the mutual influence of design and engineering parameters of the SSV, adapter and LV used to launch them.

The interaction of a Prandtl–Meyer wave and a quasi-one-dimensional flow region

A mathematical model for the interaction between a Prandtl–Meyer flow and a quasi-one-dimensional subsonic or supersonic stream is developed. The analytical description of the shape of the slipstream dividing two interacting streams is achieved, and its parametrical analysis is performed. The results of the study may be of practical use in supersonic jet flow–obstacle interaction analysis, which is important for the safety of space vehicle launches.

Estimation of acoustic loads on a launch vehicle fairing

During the launch of space vehicles, there is a large external excitation generated by acoustic and structural vibration. This is due to acoustic pressure fluctuations on the vehicle fairing caused by the engine exhaust gases. This external excitation drives the fairing structure and produces large acoustic pressure fluctuations inside the fairing cavity. The acoustic pressure fluctuations not only produce high noise levels inside the cavity but also cause damage such as structural fatigue, and damage to, or destruction of, the payload inside the fairing. This is an important problem because one trend of the aerospace industry is to use composite materials for the construction of launch vehicle fairings, resulted in large-scale weight reductions of launch vehicles, but increased the noise transmission inside the fairing. This work investigates the nature of the external acoustic pressure distribution on a representative small launch vehicle fairing during liftoff. The acoustic pressure acting on a representative small launch vehicle fairing was estimated from the complex acoustic field generated by the rocket exhaust during liftoff using a non-unique source allocation technique which considered acoustic sources along the rocket engine exhaust flow. Numerical and analytical results for the acoustic loads on the fairing agree well.

Foundations of a concept for constructing and developing on-board radio-telemetry system and software-hardware means in the telemetry complex of space-vehicle launch sites

The most rational scenarios for strategies for constructing and developing on-board telemetry systems and software-hardware means for the telemetry complex of a space-vehicle launch site are determined on the basis of previous research and a problem-oriented morphological analysis. The appropriateness of the current choice of scenario is justified in terms of the actual development of these systems and equipment and the corresponding information technologies.

Polymer Combustion as a Basis for Hybrid Propulsion: A Comprehensive Review and New Numerical Approaches

Hybrid Propulsion is an attractive alternative to conventional liquid and solid rocket motors. This is an active area of research and technological developments. Potential wide application of Hybrid Engines opens the possibility for safer and more flexible space vehicle launching and manoeuvring. The present paper discusses fundamental combustion issues related to further development of Hybrid Rockets. The emphasis is made on the two aspects: (1) properties of potential polymeric fuels, and their modification, and (2) implementation of comprehensive CFD models for combustion in Hybrid Engines. Fundamentals of polymeric fuel combustion are discussed. Further, steps necessary to accurately describe their burning behaviour by means of CFD models are investigated. Final part of the paper presents results of preliminary CFD simulations of fuel burning process in Hybrid Engine using a simplified set-up.

Physical simulation of dry microburst using impinging jet model with swirl

Severe thunderstorm is an important weather phenomena, which impact on aviation, space vehicle launching, agriculture in addition to its damage potential to life and properties. One of the most important event in the thunderstorms is the “Downburst”. It consists of slow rotating column of air, which burst violently after reaching the ground. It is believed that a downburst is generated when the upward moving moist buoyant air can no longer be sustained above and subsided into downdraft. The flow due to downburst impacts on the ground and spreads outward in different directions. Downbursts are classified as either microburst or macroburst depending on their horizontal extent of damage. In this work, an attempt has been made to simulate the dry microburst (microburst not accompanied by rain) experimentally using the impinging jet model for investigating the macroflow dynamics and scale (Reynolds number) dependency of the downburst flow. Flow visualization is done using a smoke generator for understanding the flow dynamics.

LINKING MODULARITY TO SYSTEM ASSEMBLY: INITIAL FINDINGS AND IMPLICATIONS

The existing literature on system modularity postulates several benefits of modular systems. One reason the military has taken an interest in modularity is to allow responsive design, build, and launch of space vehicles. Researchers have developed modularity metrics, but the literature acknowledges a lack of application of modularity metrics. This paper describes some of the salient modularity metrics and applies them to a case study involving two modular precision guided munitions (PGM) as an illustrative example for potential application to motivating challenge of responsive space vehicle launches. A discrete event simulation model of the assembly process for each system in the case study is described, followed by an examination of modularity metrics with respect to system assembly times. Finally, a discussion regarding the relationship between modularity and system assembly time is presented with possible implications.

Launching astronauts: 50 years of electronic checkout and launch systems at the Kennedy Space Center

When NASA was created in 1958 one of the elements incorporated into this new agency was the Army Ballistic Missile Agency (ABMA) in Huntsville, Alabama and its subordinate Missile Firing Laboratory (MFL) in Cape Canaveral. Under NASA, the MFL became the Launch Operations Directorate of the George C. Marshall Space Flight Center in Huntsville, but expanding operations in the build-up to Apollo dictated that it be given the status of a full-fledged center in July, 1962 [1]. The next year it was renamed the John F. Kennedy Space Center (KSC) after the president whose vision transformed its first decade of operation. The ABMA was under the technical leadership of Dr. Wernher von Braun. The MFL was run by his deputy Dr. Kurt Dehus, an electrical engineer whose experience in the field began in the early days of V-2 testing in war-time Germany. In 1952, a group led by Dehus arrived in Cape Canaveral to begin, test launches of the new Redstone missile [2]. During the 1950s, the MFL built several launch complexes and tested the Redstone, Jupiter, and Jupiter C missiles. This small experienced team of engineers and technicians formed the seed from which has grown the KSC team of today. This briefly reviews the evolution, successes, and setbacks of KSC electronic technologies for integration, checkout, and launch of space vehicles and payloads. We show that this very successful technology development was driven by greater vehicle complexity and heavily influenced and constrained by the commercial state-of-the-art in electronics.

Human Factors Engineering for Space Exploration Missions

NASA now has a focused mission for space exploration. We will continue to use ground based analogs and simulators, the Space Shuttle and the International Space Station as research and development platforms, but the challenges of time, distance and very hostile environments raise the challenges to human factors engineering designers to an even greater level. We will have a new generation of vehicles, equipment, habitats and space suits; operations and activity management will present novel scheduling, training and task allocation opportunities. The safety stakes will also be higher and the cold euphemisms of risk management will require some humanization, both for the crew and the public. Space vehicle launch, docking, navigation and landing will require complex interactions between automation and human operators. Commanders and pilots will require considerable simulator training and will be expected to perform flawlessly despite the debilitating exposure to extended time in space. Physical tasks on planetary surfaces will require protective suits that allow explorers to function effectively without the risk of excessive fatigue. Deviations from our familiar 24 hour day night cycle will demand innovative countermeasures if crew members are not to succumb to performance decrements due to cumulative sleep deprivation. Operation of complex life support, transportation, emergency response and scientific systems will require the development of effective and efficient job aids and procedures. Planetary surface habitats will be designed with the life support systems and home comforts necessary for long duration tenure. Finally, the safety of the human crew will be paramount and will require robust hybrid human-robotic systems, activity schedules and operations management. The NASA space human factors community is addressing these challenges by observing the performance of crew members in analogs, simulators and real missions and supporting this activity by basic and applied research in NASA laboratories and in collaboration with external scientists. The presentations in this panel will describe some of the current efforts to support this focused NASA exploration mission.