Development Of Space Vehicles Research Articles

Improved ablation resistance of silicone/phenolic hybrid resin coatings with Zr-Si-O glass as anti-ablation layer

With the development of the new generation space vehicles, traditional phenolic resin (PR)-based coatings are no longer able to meet the increasingly harsh thermal environment. There is an urgent need to develop higher performance PR to ensure the flight safety of aircraft. Therefore, in this work, a novel hyperbranched polysiloxane containing Si-O-Zr bond was synthesized and then introduced into PR to develop homogeneous silicone/phenolic hybrid resin coatings. The TG results indicate that the introduction of Si-O-Zr bonds significantly improves the heat resistance of silicone. During ablation, the hyperbranched polysiloxane will undergo a ceramization to produce SiO2 and ZrO2 particles, both of which will subsequently generate a highly viscous Zr-Si-O glassy phase as anti-ablation layer. With the fluidity and self-healing properties, it can fill the gaps of the carbon layer and cover the surface of the carbon layer, giving the hybrid resin excellent ablative resistance. The linear ablation rate of the hybrid resin can be as low as 0.003 mm/s, which is an 80 % decrease compared to pure PR. The synthesized hybrid resin is expected to act as superior thermal protection coatings for the next generation of spaceflight.

Incremental model predictive control for satellite de-orbiting based on drag modulation

This paper deals with the problem of controlled atmospheric re-entry, which has recently gained growing interest from the aerospace scientific and industrial communities for the economic and environmental benefits related to the development of reusable space vehicles. In this context, an original technique based on the incremental formulation of the Model Predictive Control methodology is proposed to tackle the trajectory tracking problem of a small satellite equipped with a deployable heat shield in the de-orbiting phase, focusing on a range of altitude from 300 km to 130 km, i.e., before the atmosphere is dense enough to begin a terminal re-entry phase. The proposed control logic allows following a given pre-determined guidance law, limiting position offsets due to unmodelled disturbances or uncertainties in the knowledge of spacecraft parameters (e.g., drag coefficient). An extensive numerical simulation campaign to assess the control performances in different perturbing conditions has demonstrated its ability to reach a km-error level in the position error at the final altitude of 130 km.

Review on Sustainable Development of Space Vehicles

Abstract: As humanity is moving towards becoming a multi-planetary civilization, it is very important to make efficient use of resources available on our planet first and then head towards exploiting the resources of another celestial body. It is also important to cause minimum harm to the space environment around our planet as well as the planetary atmosphere. Advancement in conventional rocket fuel is one of the ways to optimize the consumption of fuel during a space launch but it cannot always be feasible. Finding cheaper alternatives like Biofuels can also be a significant point of discussion. Such fuels can be naturally obtained without much harm to the environment and they can be as effective as conventional rocket fuel. For complete sustainability, not only internal changes but also external changes should be considered. To attain space sustainability, we need to follow a technology-driven approach while considering the cost and effective management of the space missions. This paper is a review of various techniques involved in the sustainable development of space vehicles, and effects of existing techniques involved during the launch of the space vehicle.

Design and integrated tension test of a large-scale modular CFRP wheel-spoke-shaped structure

The development of large-scale space flight platforms and space vehicles has led to the definition of ultra-lightweight and large-span structural design requirements for backbone structures. Taking the large-scale production, lightweight, modularization, and rapid assembly requirements as the optimization design goals, the modularization technology, connection method, and assembly mode of a carbon fiber reinforced polymer (CFRP) truss structure are studied; leading to the proposal of a new modular design scheme for large-scale modular CFRP wheel-spoke-shaped pre-tensioned structure. Based on the single-point synchronous graded tensioning method, an integrated tension test of the large-scale modular CFRP wheel-spoke-shaped structure is carried out with an integrated tension equipment. The consistency of the strain changed when the upper and lower radial cables was tested, the strain characteristics of the triangular joint frame and the CFRP truss during the push-tensioning process were analyzed, and the overall deformation of the large-scale modular CFRP wheel-spoke-shaped structure was studied. The proposed single-point synchronous graded tensioning method can simply and efficiently perform tensioning consistency in the prestressed cables, and therefore solve the engineering issues of low precision, complex tension application, and assembly difficulties in existing circular multi-point synchronous graded tensioning method. The large-scale modular CFRP wheel-spoke-shaped pre-tensioned structure achieves both structural weight reduction and large-scale structural design goals, while having broad application prospects in various aerospace vehicles and space structures. The proposed modular technology, wheel-spoke structure design scheme, and single-point synchronous graded tensioning method have high a scientific contribution, while providing technical support for the development of new spacecrafts.

State of research and development of small spacecraft with optical communication

The current state of scientific and technical research and development of small space vehicles using optical communication systems is considered. The problems standing in the way of creating intersatellite optical communication are discussed as well as the mutual position of satellites determination and it tracking. Scientific tasks for the implementation of the development of an optimal reliable control system for satellite communication are defined.

The 35th Anniversary of the Launch of Mir’s First Module: Main Results of Applied Scientific Research and Experiments Carried Out Onboard the Manned Orbital Complex.

For 15 years (1986–2001) the orbital station “Mir” served as the only manned space laboratory for long-term scientific and technical experiments and human body research in space. This multipurpose international complex began to op-erate on February 20, 1986 when its base module was placed into orbit. The re-sults, obtained during that period, have made a great contribution to domestic fundamental science and today they are of great practical value for various sectors of the national economy, education, health care, and development of space vehicles.

The Influence of Si3N4w Volume Fraction on the Microstructure and Properties of Si3N4w/Si3N4 Composites via CVI Technique

Wave-transparent ceramic composites with excellent comprehensive performances are of particular significance for the development of space vehicles. In this study, Si3N4w was prepared by the gel-casting process and then combined with chemical vapor infiltration (CVI)-obtained Si3N4 to yield Si3N4w/Si3N4 composites with five Si3N4w volume fractions. The influence of the Si3N4w volume fraction on the microstructures, mechanical properties, and dielectric characteristics of the Si3N4w/Si3N4 composites were all studied. The results showed that Si3N4w/Si3N4 composites possess A sandwich structures. Higher Si3N4w volume fractions led to less incorporated amounts of the Si3N4 matrix at the same depth. The 25 vol% Si3N4w/Si3N4 composites integrated relatively higher Si3N4w volume fraction and load transfer ability of the matrix, leading to better flexural strengths reaching up to 41.37 MPa. The dielectric constants of the five prepared Si3N4w/Si3N4 composites ranged from 2.25 to 4.0. The dielectric losses were all lower than 0.005, demonstrating the good dielectric properties of the Si3N4w/Si3N4 composites.

The Wind Environment Interactions Relative to Launch Vehicle Design

Since atmospheric winds play the most critical natural enviroment (NE) role as input into the design and development of an aerospace launch vehicle, this paper provides a more detailed description of the wind environment and its interaction with engineering design in launch and space vehicle development applications at Kennedy Space Center (KSC).

Space migrants

Man has dreamed of stars since their origins, they have inspired hundreds of great thinkers, artists and religious to understand why they are there, to understand how the celestial map changed night after night, imagining that we could reach them and find new and fantastic worlds, as well as unthinkable flora and fauna. Progressively, as science and technology advance, we can feel that those dreams are closer and closer to being realized. Today we are mainly focused on conquering Mars and although still distant, this idea starts to sound feasible. Using probes and terrestrial drones, we have been able to see the planet, decisive and transcendental steps, but they are the beginnings of a great sequence of necessary objectives before a human being can call the red planet "home". This article addresses the main challenges and obstacles that we would have to overcome in order to start an exodus to Mars, such as development of space vehicles, habitats, and environmental suits, generation of oxygen, water, food and energy, as well as essential genetic modifications.

АНАЛІЗ ВПЛИВУ ОБСЯГУ ГІДРОАКУМУЛЯТОРУ НА ПРАЦЕЗДАТНІСТЬ ДВОФАЗНОГО КОНТУРУ ТЕПЛОПЕРЕНОСУ СИСТЕМИ ТЕРМОРЕГУЛЮВАННЯ КОСМІЧНОГО АПАРАТУ

The world trend in the development of space vehicles is the expansion of their functionality, which leads to an increase in the power consumption, most of which is allocated in the elements of spacecraft equipment in the form of heat. To remove heat from the equipment elements, transfer it to the heat sink subsystem with subsequent removal to outer space, and also to maintain the required temperature mode of the equipment operation, thermal control systems are used. The increase in the power-to-weight ratio and linear dimensions of new spacecraft in conditions of severe design and weight-and-size limitations leads to a complication and growth of the mass of the system of thermal control of space vehicles. At present, thermal control systems for space vehicles based on single-phase fluid heat transfer loops are used. For space vehicles with an energy consumption of more than 10 kW, thermal control systems based on two-phase heat transfer loops are the most promising. They have a number of advantages in comparison with single-phase thermal control systems: two-phase heat transfer loops can transfer much more heat per unit of flow; the use of heat transfer during boiling allows to maintain the temperature of objects practically on the whole extent of the circuit close to the saturation temperature; the mass of the thermal control system with a two-phase coolant is substantially less than with a single-phase coolant , and the energy consumption of the pump for pumping the coolant is negligible. In this paper, a two-phase heat transfer loop performances are analyzed. The process of increasing the thermal power up to the maximum under conditions of full filling of the accumulator is considered. The study was carried out on an experimental two-phase heat transfer loop with an ammonia. Transient processes associated with an increase in the thermal load from 73 % to 100 % are considered. The obtained data correlate well with the results of the calculation. Based on the results of the analysis, conclusions were made on the operability and stability of the spacecraft thermal control system under these conditions, and recommendations on the choice of the volume of the accumulator are given.

Effects of two-phase inlet quality, mass velocity, flow orientation, and heating perimeter on flow boiling in a rectangular channel: Part 1 – Two-phase flow and heat transfer results

Lack of understanding of flow boiling behavior in reduced gravity poses a major challenge to the development of future space vehicles utilizing two-phase thermal control systems (TCSs). A cost effective method to investigating the influence of reduced gravity on flow boiling is to perform ground experiments at different orientations relative to Earth gravity. This paper is the first part of a two-part study aimed at exploring flow boiling mechanisms of FC-72 in a rectangular channel heated along one wall or two opposite walls. Experiments are performed in vertical upflow, vertical downflow and horizontal flow, subject to large variations in mass velocity, inlet quality and wall heat flux. Detailed measurements are used to investigate the influences of orientation, and therefore gravity, on boiling curve, local and average heat transfer coefficients, and pressure drop, and their relationship with interfacial behavior is captured with high-speed video. For horizontal flow, the effects of gravity are reflected in appreciable stratification across the channel at low mass velocities, with gravity aiding vapor removal from, and liquid return to the bottom heated wall, while accumulating vapor along the top heated wall. For vertical upflow and vertical downflow, with both single-sided and double-sided heating, there is far better symmetry in vapor formation along the channel. The heat transfer coefficient shows significant variations among the different orientations and heating configurations at low mass velocities, but becomes insensitive to orientation above 800kg/m2s, proving inertia around this mass velocity is effective at negating any gravity effects. For low mass velocities, pressure drops are fairly equal for vertical upflow and vertical downflow, but greater than for horizontal flows. However, fairly equal pressure drops are achieved at high mass velocities for all orientations. Overall, this study proves that gravity effects on two-phase pressure drop and two-phase heat transfer are dictated mostly by mass velocity and, to a lesser extent, by inlet quality.

2214 製品情報と運用情報の組み合わせ探索による概念設計手法の研究 : 第1報 宇宙機設計のための概念設計手法の枠組みの検討(OS15-2 技術経営2,OS15 技術経営)

It is necessary to design the new concept of the space vehicles in order to survive the space market in the world. However, although concept design is particularly important in space vehicle development to add value and reliability, it is difficult to apply conventional shape-based CAD/CAE systems to the concept design stage due to the lack of detailed design information at that stage. In this paper, we suggest the new design method (Product and Operation design method) that can support concept design of space vehicles by many kinds of Products and Operations produced by orthogonal table. By using this design method, we can design space vehicles in comparison with another design plans, and design the new space vehicles (e.g., multi-purpose space vehicles, or constellation satellites.). The prototype system based on the design method is implemented, and some examples applied for the concept design of super-sonic vehicle "SEED" are shown.

Knowledge Management Platform at Taiwan Aerospace Industrial Development Corporation (AIDC): A Case Study

Aerospace industry development embodies national competitiveness. Generally speaking, the aerospace industry is considered to be a knowledge intensive industry. The Aerospace Industrial Development Corporation (AIDC), affiliated with a state-operated corporation belonging to the economic ministry cabinet, has years of experience with space vehicle development. It also has rich experience with aircraft design, testing, manufacture, logistics, and so on. Because of the cutthroat competition in the knowledge economic era, AIDC decided to establish a knowledge management platform aimed at raising corporate value and core competencies, and at moving forward to sustainable management. The study was conducted on the basis of a case study accessed through AIDC's internal research methods. The author, who had the experience of being a process integration engineer from 2002 to 2006 at AIDC, discusses the construction of a knowledge management platform at AIDC, analyzed internal knowledge sharing and transmission among employees, and determined its impacts on individual work. The purpose of the study is to find whether there were positive or negative impacts on business operation after the concept transmission of knowledge management and the creation of knowledge management tools. Knowledge management enhancement at AIDC can be divided into four stages: strategy, advocacy, introduction, and innovation. The study analyzed the work effectiveness of knowledge management in practice through four years of internal observation and recording, and discussed electronic auxiliary tool applications such as AIDC's Engineering System, Lotus Notes, the AIDC KM System, et al. As a result, knowledge management is implemented among executive classes. The study, which discussed the boosting and blocking roles of knowledge management, could be referenced as an example for knowledge management enhancement of other medium-sized and small enterprises in Taiwan.

Modest but uneven R&D increases proposed for FY 2013

Uncertainty created by the Budget Control Act of 2011 clouds the outlook for federal science and technologyfunding. Some Department of Energyphysics programs face significant cuts.

Feasibility of the recent Russian nuclear electric propulsion concept: 2010

The paper introduces recent Russian nuclear electric propulsion (NEP) concept for space exploration. The concept advantages are listed along with future missions. The current development status for the two main enabling technologies is presented and the feasibility analysis of the up-to-date experience is performed. The main features of NEP concept are discussed. Revision of these features and available technologies demonstrates that the NEP concept is a logical continuation of the previous efforts by the former Soviet Union. Because no breakthrough technologies are needed for NEP development while the existing technologies only need to be adapted to the megawatt (MW) class NEP the development is considered technically feasible, low risk program likely to succeed unless cancelled by the listed non-technical reasons. Successful NEP space vehicle development is going to bring practical space exploration of solar system to the new level as well as require supplementary payload program, supporting monitoring and communication radar networks. Nuclear safety during future NEP missions can be ensured by adherence to the United Nations guidelines in the same way it was done during the Soviet Topaz Nuclear Power System (NPS) missions.

Mass growth in space vehicle and exploration architecture development

Inert or dry mass in aerospace systems has historically grown during aerospace vehicle development because of a number of factors: changing requirements, uncertainty in the performance of the initial technology selection, addition of redundancy, errors in the original design, as well as uncertain masses and loads. In the case of exploration architectures for lunar missions, compounding effects of a multi-staged mission design makes mass-efficient vehicles a necessity for achieving the total delta-V performance required to reach the lunar surface and return to Earth. Current standards and guidelines for mass growth risk mitigation are compared, including the industry and NASA standard methods for risk management and mitigation through the application of mass margin. Historical mass growth trends are analyzed, and average levels of growth are compared to the standard margin allocation levels. Analysis of the available historical data shows that the mean inert mass growth is 28%, and 30% of historical programs experience inert mass growth in excess of the allowable growth and margin recommended level of 32.5%. As an illustrative example of the mass growth of lunar exploration architectures the mass growth sensitivity of the Apollo architecture is calculated. Results show that a kilogram of mass growth on the lunar ascent stage is compounded over 800 times in gross mass.

Heat Flux Duplication Between Ground Facility and Hypersonic Flight

The development of reentry space vehicles requires a precise qualification of their thermal protection system materials. The material catalytic properties should be determined for test conditions relevant to the real flight mission program. However, perfect reproduction of the flight environment in a ground facility is practically impossible for reacting flows and one is obliged to resort to a partial simulation. In an attempt to overcome such an issue, we present a methodology that allows establishing under which hypothesis and approximations the flowfield inside a ground facility is equivalent, regarding the heat flux load, to the real flowfield experienced by a space vehicle. The analytical results of the theory are compared with numerical predictions and agree favorably with them.

Factors influencing the acoustic characteristics of the reverberation chamber

Main factors influencing the characteristics of the acoustic reverberation chamber are considered. Studies of mode density and calculation of required acoustic power are carried out from the relations of the RK-600 chamber dimensions depending on technical requirements for the ground-based experimental development of communication space vehicles (SV).

Effects of heat treatments on oxidation resistance and mechanical properties of ultra high temperature ceramic coatings

A critical point in the development of future generation space vehicles is the availability of materials able to withstand the extreme temperatures generated during orbital re-entry. UHTC (Ultra High Temperature Ceramics) materials, such as Zirconium diboride based ceramic composites, exhibit outstanding oxidation and thermal shock resistance, high emissivity and very high melting temperature: all these properties make ZrB 2 based materials possible candidates in designing thermal protection systems for the hottest structures of re-entry vehicles such as wing leading edges and nose-tip. An innovative, proprietary way to deposit ZrB 2 based coatings by plasma spraying has been developed. In the present work, the influence of high temperature exposure on oxidation resistance and mechanical properties has been investigated. Several coatings constituted by different amounts of SiC particles dispersed in a ZrB 2 matrix were produced; some samples were tested in as sprayed conditions, other ones were submitted to a high temperature heat treatment before testing. Oxidation resistance was determined by exposing samples in air at 2073 K for 180, 1800 and 2520 s. Oxidation kinetics were analyzed and modelled. Evaluation of flexural strength and elastic modulus by means of four-points bending tests were carried out on samples showing better oxidation behaviour; mechanical tests were performed also on samples exposed at a typical operative temperature (1800 s at 2073 K). Results showed that heat treatment does not affect oxidation resistance, whilst it significantly improves mechanical properties.

Whole-field NDT of thermal protection system using digital holography

In the development of re-entry space vehicles, thermal protection systems (TPS), which protect the vehicle from the high thermal environments during re-entry, constitute one of the most critical systems. Both metallic and non-metallic materials are candidates for TPS. Generally, the TPS materials are bonded to the structure in vacuum under load. For the successful performance of the vehicle, the TPS should be intact to the vehicle without any debond and hence the detection of debonds in TPS is very important. Holographic interferometry is established as a reliable NDT tool for detecting debonds. Digital holography is a technique that uses digital recording and numerical reconstruction of holograms, which does not require photographic films, wet processing and laser reconstruction. In this paper the application of the digital holographic interferometry technique in detecting debonds in different types of thermal protection systems is presented. The results of the tests on a few samples made of ablative and non-ablative TPS materials with debond are presented. The paper also describes the experimental details and stressing techniques used for the detection of debonds in TPS. The practical application of this technique for the NDT of TPS is explored.