Sharif Digital Repository

One of the most interesting and at the same time the newest methods to launch a satellite into space is Air Launch or Launch throw the mother aircraft. The placement of the satellite into space by a rocket in specific altitude and speed is separated from the mother aircraft, takes place. The most problems in multi stage rocket launching is trajectory optimization to reaching the maximum height. The survey was conducted using classical optimization methods, which is derived the equations for the gradient based on the calculus of variations. that can be used or modified for emissions control wings and changing the direction of thrust exhaust. It should be noted that in the model of rigid body... 

In sending a man into space, the protection of the lives of the astronauts is very important and must ensure them stay healthy. To launch a human into space must design a system that if creates a problem can protect the lives of astronauts. To achieve this goal requires the design of a system for launch vehicle that be named launch cancellation system (emergency escape system). In this project, the launch escape system for manned lauch vehicle is designed. The cargo carrier serves as input for the problem and then the system is designed to build in our country. First, to study emergency escape systems in the world were discussed and sub-systems and scenario of flight was specified for... 

In this thesis first a flrxible launch vehicle is modeled and simulated by taking the moment vibrations into consideration, then navigation system and it’s uncertainties which depicts more realistic performance are added up and the guidance is designed based on pitch-programming. Adaptive robust controller is designed and implemented with the approach of sliding mode such that making the system able to keep it’s despite of navigation uncertainties and flexibilities, also controlling the attitude in the framework of adaptivity and robustness  

As a strategically critical stage of new product development, launch process has attracted a lot of attention. A lot of study has been done about launch and its effect on product performance.The objective of this thesis is to gain more understanding about new product launch and the way it is executed. The aim is to create a process description of product launch; how the process begins and how different phases follow each other until the introduction of new product. The main research problem is how new product launch can be described as a marketing-focused process. Further, the research problem is answered through literature review and empirical case study research. The literature review... 

In this research the problem is the development and simulation of Transfer Alignment algorithm for an aerial launch space launch vehicle. In the references there is no complete study on development of this algorithm for the case space launch vehicle. In order to develop the algorithm, the carrying airplane and the space launch navigation systems are considered as the Master INS and Slave INS respectively. First a 6DOF simulation of the airplane is presented. Then the desired inputs for simulation of Master and Slave INS are generated. Also the differences of the inputs of Slave INS caused by the distance between the Master and Slave INS is considered. Master INS performs as an ideal INS and... 

An optimal-fuzzy low altitude two phase CLOS guidance algorithm for a vertically launched flying vehicle is presented. In addition, the required relations for determining the proper rotation angle of interceptor in the launch phase are derived. The guidance algorithm is designed for a three point guidance system and utilizes fuzzy sliding mode control as a regulator to compensate the guidance loop errors. Furthermore, for the purpose of trajectory shaping, a fuzzy system was employed to calculate the augmented elevation angle. Finally, a multi-objective optimization algorithm is used to determine 20 unknown parameters of the guidance law and 11 parameters of trajectory shaping system.... 

A carrier should be used a guidance system for reaching to the point of injection in an orbit. The main purpose of guidance system in the injection process is issuance of guidance commands to achieve the final desirable velocity and position. These velocity and position indicate the purpose orbit for injection. Carrier is a dynamic system which is described by mathematical terms. In general carrier guidance systems apply pitch angle or rate of pitch angle to reach specific path over injection process. Different methods are available for carrier guidance such that preset method. In this method, the guidance system addresses specific guidance commands and control system performs these... 

One of the satellite time-critical launch methods is air-launch, which is considered in this research thoroughly. The Large number of important parameters of this method makes the system highly complex. In such complex systems, usual methods of design and development will not be effective. Moreover, based on systemic approaches, interfaces between different elements of a complex system have significant effects on the performance of the whole system. One of the methods for analysis of such systems is “Design Structure Matrix” or DSM. This method is based on system engineering principles and has confirmed capabilities in analysis of highly coupled systems.
In this research, the air launch... 

The importance of New Product Development (NPD) projects has been realized more and more in recent years. Among different decisions to be made in NPD process, one of the most critical decisions is about the best time to launch new product(s). Due to existence of many internal and external influential factors, determining the optimal launch time is often too complicated and it is quite hard to systematically analyze it. Despite risky nature of NPD, risk considerations in determining the optimal launch time have not been addressed in literature due to the mentioned complexity. In this research, we developed a model that takes in to account risk considerations while systematically determining... 

Launch vehicle must overcome gravity and place its payload on determined orbit. Multi-staging of launch vehicles causes that the ratio of length to diameter become large and then launch vehicle behave elastically. In this study, the equations of motion using the Lagrangian approach drive at pitch plane. By adding elastic terms to control equations, the launch vehicle modeling is completed. Predictive model controller choose for control system.This controller is based on neural network. In this paper, the main concepts and neural network approach in this controller structure is introduced.Finally implementation of this method in Simulink environment for pitch control of a flexible launch... 

In this research, a Reusable Flexible Launch Vehicle (RFLV) design problem is presented by Multi-Disciplinary Design Optimization (MDO) approach in primary design phase. Trajectory, structure, aerodynamic, aeroelasticity and thermal protection system are considered as involved disciplines in design problem. The study purpose will be to obtain an optimal trajectory which meets all the control and structure limitation while the estimating body skin and thermal protection thicknesses base on structural evaluating in re-entry trajectory is in process. The flexible launch vehicle body is considered as a free-free Bernoulli-Euler beam and D’alembert’s principle addresses inertia force in static... 

The problem of launching a satellite to low earth orbit has been considered. Preliminary concepts such as satellite orbits, launcher missiles and their equations of motion, and traditional methods for guidance of launchers are reviewed first. Then a new method for optimizing the launch trajectory under non-ideal conditions is introduced in which the solution of a known ideal trajectory optimization problem is used as an initial guess for the actual optimization problem. Several methods for guiding a launcher to place a satellite in Earth orbit are presented next; they have been titled as (1) launch path re-computation outside the atmosphere, (2) prediction error minimization, and (3) output... 

In this study the interaction of sloshing and structural vibrations equations in tanks are investigated and developed. For this purpose the governing equations of structural dynamics and potential flow are used and a reduce order model for fluid is derived. Three methods are used for external forces calculation of structural dynamics model which are the sloshing fluid, quiescent fluid and lumped mass. Then free vibrations of coupled system for launch vehicle with two tanks is investigated. The results of this study are compared and validated with existent results in the literature and finally the effects of fluid height in tank, tank thickness and parameters of launch vehicle like... 

Nanolaunchers are launch vehicles capable of carring light payloads (under 50 kg) to Low Earth orbit and received much attention in the few past years. Launching the nanosatellites grown about 30 times from 2008 to 2017. Since this category of launch vehicles has fewer developing costs and lower thechnology level, they fit developing space technology in our country. Conversely, the demand of high propellant mass fraction and specific impulse may be a serious difficulty to attain this technology.The only operating nanolauncher in the world is SS-520-5 which belongs to Japan and is a three-stage solid propellant launcher. The goal of this project is also the conceptual design and feasiblity... 

Hand-launched UAVs are type of unmanned aerial vehicles that due to transportability and geometric specification, are operationally valuable and worthy. reconnaissance & surveillance (aerial mapping, aerial filming, inspection, border protection); health care (blood transport, body organ transport, medicine delivery); agriculture (farm monitoring, fertilization, cloud seeding); payload delivery (envelopes posting); network covering (internet supply, telecommunication relay); crisis management (remote area medical) are some of typical applications and missions of this type of aircrafts. These UAVs have almost low altitude short endurance (below 5000 ft. and less than 2 hrs.). To extend their... 

Aerodynamics loads and aeroheating during reentry, are one of the challenging issues in designing One of the main challenges in the design and application of reusable spacecrafts is the aerodynamic and thermal loads acting on their structures during reentry into the atmosphere. For this reason, all the concepts/prototypes presented in the 20th century were either not fully reusable, or were partially canceled, or did not have economic justification. In this report, the aerodynamic loads on the first stage of a launch vehicle during the launch and return phases have been investigated. Due to the fact that the main part of the first stage of the vehicle includes fuel and oxidizer tanks, the... 

The case of rapid small satellite aerial launch by mother airplane has various applications; such as space experiment, weather monitoring, and getting information from the earth monitoring during natural disasters. In this method, the satellite and the launch vehicle will be carried up by mother airplane to the definite height; then, the launch vehicle will be released and flied - to the insert of satellite into the desired orbit. Aerial launch system success depends on a set of complex elements and their interactions. In the present study, first of all, the element interactions will be investigated by system engineering approach based on operational scenarios; then, a new approach for... 

The present thesis aims at investigating the dynamic interaction of slosh and aeroelasticity in the fuel contained aero vehicles. The main approach in this research is to develop reduced order models for description of the coupled system. In this regard, boundary element method is used to develop slosh dynamic model. Axisymmetric boundary element method with non-symmetric boundary conditions is used to develop slosh dynamic model for axisymmetric containers. Zoning method is used to develop slosh dynamic model for the multi-baffled tanks and based on it, slosh equivalent mechanical model is developed for multi-baffled tanks. Finite element method along with modal technique is used to develop... 

Today, a lot of efforts have been done in order to commercialize space travels. Spacecrafts have a lot of components and producing each of them spends high costs. Components such as propellant tanks and boosters are multi segment and are released simultaneously and therefore it is economically feasible to recover them. Due to Parafoil ability in low-cost, soft (no damage to the cargo) and accurate landing, it is gradually replacing parachute. Parafoil can fly long distances after being released, so its landing point could be determined. The aim of the study is to evaluate this scenario in which some segments of launch vehicle (e.g. booster) that are equipped with Parafoil expand their... 

The subject of systemic reliability assessment, allocation and optimization as well as structural reliability (SR) of a two stage solid fuel launch vehicle (LV) is investigated. In this regards, first the LV reliability block diagram is broken-down into appropriate subsystems. Subsequently the total LV system reliability is determined assuming the subsystems reliability. In addition, using a hybrid GA-PSO algorithm optimal subsystems redundancy levels, reliabilities as well their type are determined to simultaneously maximize the total reliability while minimizing the LV cost (weight) as a constraint. While the reliability and cost of subsystems are not precisely known, the total LV...