Syftet med denna studie var att få insikt i före detta intagnas upplevelse av sitt fängelsestraff samt sin återgång till det fria samhället. För att besvara studiens frågeställningar som lydde; hur påverkas individen av sitt fängelsestraff och hur har individen återanpassats i samhället efter fängelsevistelsen, delades resultatet upp i två avsnitt som rör tiden i fängelset och tiden efter fängelset. Urvalet bestod av sex män som har avtjänat ett fängelsestraff i Sverige, de var mellan 25-60 år. Data samlades in genom semistrukturerade intervjuer. Resultatet visar att fängelsestraff påverkar individerna både psykiskt och fysiskt på ett negativt vis. Resultatet visar även att individens inre motivation är av stor vikt när det gäller återanpassning till samhället. För att återanpassning ska ske på ett tillfredsställande vis är det av vikt att samhällsstödet erbjuds i rätt tid. / This study aimed to get insight in former inmates’ experiences, about their imprisonment and their re-entry into the free society. To answer the aim, the following questions were formulated; how does imprisonment affect the individual and how has the individual re-entered the society after imprisonment. The studies result was divided in two larger themes that concerned the time in prison and the time after. The selection for the study was six men that have been imprisoned in Sweden; they were between 25-60 years. Data was collected through semistructured interviews. The results show that imprisonment affect the individual in a negative way, both physical and psychological. The results also show that individuals inner motivation is very important when they re-entry the society and social support needs to be available to the former inmates in the right time.

La mise en œuvre de missions spatiales demande à développer de nombreuses technologies clés afin de surmonter certaines étapes cruciales. L’une d’entre elle concerne la rentrée atmosphérique : lorsque le véhicule pénètre dans la couche d’atmosphère, sa vitesse relative très grande par rapport au sol va engendrer des frottements importants ainsi qu’une augmentation de pression. L’énergie cinétique de l’objet va donc être transformée en énergie thermique et chauffer le gaz en formant une onde de choc. Les températures dépendent de la vitesse initiale, de la composition de l’atmosphère et de sa pression. Le gaz ainsi chauffé va s’ioniser et devenir un plasma, il va donc transférer sa chaleur au corps de la sonde non seulement par convection mais aussi par rayonnement. Afin de se protéger, le véhicule dispose d’un bouclier thermique pouvant résister aux phénomènes extrêmes rencontrés lors de la descente. Les contraintes supplémentaires vont imposer une géométrie particulière et un lourd bouclier. Ainsi l’objectif est d’avoir les protections les plus légères et efficaces possibles afin de permettre à la sonde de maximiser son emport en équipement scientifique. Pour cela, un des paramètres clés est de connaître le comportement et le rayonnement du plasma produit lors de la rentrée dans l’atmosphère. Cette thèse se positionne dans ce domaine d’étude: les expériences montées et réalisées ont pour objectif d’observer par moyens spectroscopiques un plasma correspondant à celui rencontré par les sondes spatiales. / Many key technologies, to overcome some crucial steps, are needed for space missions. One of them concerns the re-entry: when the vehicle enters the atmosphere layer, its high velocity relative to the ground will generate significant friction and an increase in pressure. The kinetic energy of the object will be converted into heat energy and heat the gas forming a shock wave. Temperatures depend on the initial velocity, the atmosphere composition and its pressure. The gas is ionized and become plasma, it will therefore transfer its heat to the body of the probe not only by convection but also by radiation. To protect itself, the vehicle has a heat shield that can withstand extreme phenomena encountered during the descent. Additional constraints will impose a particular geometry and a heavy shield. So the goal is to have the lightest possible and effective protections to allow the probe to maximize its payload. For this, one of the key parameters is to know the behavior of the plasma and radiation produced during re-entry into the atmosphere. This thesis is positioned in this area of ​​study: experiments to create a re-entry plasma are intended to be observed by a spectrometer.

Syftet med denna studie är att undersöka eftervård för klienter som vårdats under Lagen (1988:870) om vård av missbrukare i vissa fall (LVM). Detta genom att undersöka avgörande faktorer för utfall av eftervård för klienterna. Vidare ämnar studien att undersöka klienternas motivation till eftervård från socialarbetares perspektiv. Studien syftar till att belysa en verklig bild av eftervården och eventuella utmaningar gällande eftervården för dessa klienter. För att undersöka detta utgår studien från följande frågeställningar:-Vilka faktorer avgör vilken eftervårdsinsats klienter som vårdats med stöd av LVM får? -Hur upplever och förstår socialarbetare sina klienters motivation till eftervård?För att besvara dessa frågeställningar användes semistrukturerade intervjuer som metod för att samla information från åtta informanter. Fem arbetar på socialtjänsten i olika kommuner och tre arbetar på institutioner styrda av Statens Institutionsstyrelse (SiS). Resultatet av studien visar att alternativen för eftervård är begränsade. När olika alternativ är tillgängliga påverkar andra faktorer eftervården, såsom kommunernas budget, klienters komplexa problematik och klienters förmåga att tillgodose sig behandling. Informanterna anger även att vissa klienter likställer tvångsvården med att sitta i fängelse, vilket innebär en utmaning i motivationsarbetet som socialarbetarna utför. Vidare visar resultatet på att motivationen är låg för klienter som återkommer inom tvångsvård. Klienternas motivation till eftervård tenderar att gå igenom olika faser under tiden på institutionen vilket skapar utmaningar för socialarbetarna. Studien visar även på att ett samarbete mellan socialtjänsten och SiS är grundläggande för positiva utfall för klienterna. / The aim of this study is to examine aftercare for clients who have been in compulsory treatment under the Substance Abusers (Special Provisions) Act 1988. This is done by examining determining factors for what kind of aftercare the clients receive. Furthermore the study aims to find out clients motivation to aftercare from the perspective of social workers. The study aims to highlight the reality of aftercare and the challenges of providing care to clients post-compulsory treatment. To examine this, the study is based on the following questions:-What factors impact clients post-compulsory treatment paths?-How do social workers experience and understand their clients’ motivation for care post-compulsory treatment?To answer these questions, the used method was semi-structured interviews to gather data from five informants working at social services in different municipalities, and three informants working at institutions run by the National Board of Institutional Care. The result of this study show that the options for care post-compulsory treatment are limited. When options are available other factors impact the aftercare, such as organisational budgets, the clients’ other complex life situations apart from yet related to the addiction and the clients’ ability to embrace the treatment. The respondents also state that for some clients, compulsory treatment is like being in jail, which means engaging in motivating clients can be very challenging. Furthermore, motivation for change is low for clients who re-entry compulsory treatment. The clients’ motivation for aftercare tends to go through different phases during the time they are under care at the institutions which provide challenges for the professionals working with them. The study also found that cooperation between the relevant organisations is essential for good outcomes for clients.

The United States has the largest population of imprisoned persons in the world. The vast majority of these individuals eventually leave prison and re-enter society, facing a number of challenges in the process. Those who are unable to successfully re-enter society run the risk of recidivating back into the prison system. Mentoring has the potential to promote successful re-entry and help offenders to get their lives back on track. Pathfinders of Tarrant County is a unique organization. Its historical position as one of the foremost "welfare to work" programs gives it unique insight into the economic struggles of at-risk individuals and families, and its existing relationships with mentors and other community organizations gives it a rich pool of resources to draw from. By helping to connect participants with community resources, Pathfinders removes quite a bit of the complexity from seeking help at a time when vulnerable people need it most. This thesis presents an overview of how Pathfinders conducts mentoring and its unique brand of social service advocacy, including the unique and not-so unique challenges that a re-entry population may have to offer.

This paper will investigate the development of a landing footprint for a re-entry vehicle. Vehicles can re-enter the atmosphere with a range of orientations, velocities and flight path angles. The central question is whether a vehicle with any combination of these states can be brought to an acceptable landing condition at a particular landing site and with a particular landing speed. To aide in this investigation several models must be implemented, including that of the atmosphere, the vehicles, the Earth, and the aerodynamics. A detailed analysis of the aerodynamic model will be treated, and the equations of motion subject to these aerodynamic laws will then be compared to results from existing atmospheric reentry software. The principles of optimization will then be employed to generate the footprint of landable states, based on maximum and minimum possible downrange distances, for two vehicle concepts.

L’augmentation rapide de l’interdépendance mondiale, provoquée par le développement de la mondialisation, exige une redéfinition de la notion traditionnelle de l’éducation supérieure. Au Canada, comme dans le reste du monde, plusieurs universitaires, fonctionnaires du gouvernement et étudiants insistent maintenant sur l’intégration de l’internationalisation dans l’éducation supérieure à travers des échanges interculturels et des études à l’étranger, dans l’espoir que les générations canadiennes à venir développent une perspective globale et deviennent des « citoyens du monde » (Comité consultatif sur la stratégie du Canada en matière d’éducation internationale, 2012). Pourtant, pour garantir que l’étudiant qui participe à un échange profite le plus de son expérience internationale, nous devrons comprendre comment une telle expérience l’influence tant à court terme qu’à long terme. Bien que d’autres études se soient concentrées sur le court terme (le séjour à l’étranger et ses impacts immédiats), peu ont examiné le retour de l’étudiant, sa réintégration dans sa société d’origine et les effets subséquents à long terme, tels que les développements personnels qui pourraient suivre le rapatriement. Cette étude qualitative examine les témoignages de huit étudiants au premier cycle de l’Université de Montréal sur la façon dont ils ont vécu leur rapatriement à Montréal après un échange pédagogique à l’étranger. Quoique certains chercheurs présentent la notion de rapatriement comme une série d’événements déconnectés, notre analyse fait ressortir une tendance similaire dans tous nos témoignages qui nous permet dorénavant de considérer ce rapatriement comme un processus en trois étapes interconnectées. En empruntant à la théorie Intercultural Personhood de Kim (2008), nous sommes désormais en mesure de qualifier ces trois étapes comme étant le stress, l’adaptation et l’évolution. Non seulement cette interprétation nous aide à mieux comprendre les difficultés rencontrées par l’étudiant à l’occasion de son retour, mais elle facilite également l’identification des transformations identitaires qui apparaissent à ce moment-là et la manière dont ces transformations influencent le processus de rapatriement. / The rapidly increasing interconnectedness of the world brought on by the expansion of globalization calls for a redefinition of the traditional notion of higher education. As such, many Canadian educators, government officials, and students alike are insisting on the importance of internationalizing higher education through intercultural exchanges and studying abroad, in the hopes that current and future generations of Canadians will acquire a global perspective and become citizens of the world (Advisory Panel on Canada’s International Education Strategy, 2012). Yet in order to ensure that students are gaining the most from their international experience, it is important to understand the impact that studying abroad can have, both in the short and long term. While many past studies have focused on the short-term, or the actual time spent abroad and subsequent impacts, few have examined the exchange student’s re-entry into their society of origin and subsequent long-term effects, such as personal developments that surface during repatriation. In this qualitative study, eight undergraduate students from the University of Montreal were interviewed regarding how they lived their reintegration into Montreal society after returning home post studying abroad. While academics that have broached the subject in the past tended to view repatriation as a static series of events, our data analysis showed a similar pattern that surfaced in all respondents’ testimonials allowing us to henceforth recognize this repatriation as an interconnected three-step process. By borrowing from Kim’s theory of Intercultural Personhood (2008), we are now able to define these three distinct phases as stress, adaptation, and growth; all of which not only help to better understand the difficulties students face during their process of reintegration but also facilitate the identification of possible identity transformations that surface upon re-entry and how these transformations impact the repatriation process.

The Kentucky Re-entry Universal Payload System (KRUPS) is an adaptable testbed for atmosphere entry science experiments, with an initial application to thermal protection systems (TPS). Because of the uniqueness of atmospheric entry conditions that ground testing is unable to replicate, scientists principally rely on numerical models for predicting entry conditions. The KRUPS spacecraft, developed at the University of Kentucky, provides an inexpensive means of obtaining validation data to verify and improve these models. To increase the technology readiness level (TRL) of the spacecraft, two sub-orbital missions were developed. The first mission, KUDOS, launched August 13th, 2017 on a Terrier-Improved Malamute rocket to an altitude of ~150 km. The second mission, KOREVET, launched on March 25th, 2018 on the same type of rocket to an altitude of ~170 km. The chief purpose of both missions was to validate the spacecraft design, ejection mechanism, on-board power, data transmission, and data collection. After both missions, the overall TRL improved from 4 to 5 by validating most subsystems in a relevant environment. Both of these missions were invaluable preparation for the project's ultimate goal of releasing multiple experimental testbeds from the ISS.

Women are returning to study as mature age students in increasing numbers. Typically, these women have been away from study for a number of years and, in order to gain entrance into a university course most women are required to undertake a bridging program. Bridging programs can provide women with an alternative pathway into university and are designed to develop the academic and study skills required to successfully undertake undergraduate studies. The Women into Science and Technology (WIST) bridging program, offered by Central Queensland University, is a self-paced bridging program which provides a low cost, study at home option specifically designed to accommodate women’s needs. This research focuses on the perceived needs of women who are enrolled in the WIST program. To this end a survey instrument has been developed to identify the needs and challenges of women undertaking the WIST program. This instrument was used to explore the needs and challenges of women enrolled in the WIST program. The survey results revealed that women have a range of needs which include support from the university, development of study and academic skills, personal qualities such as motivation and determination as well as support from their family and personal networks. The results indicate that the university needs to provide a range of support mechanisms and processes. These outcomes were used to develop the Get SET for Study framework that can be used for the planning and design of bridging courses similar to WIST for women who are considering enrolling in university.

Vikram Sarabhai Space Centre,Trivandrum / In the space surrounding the earth there are two major regions where orbital debris causes concern. They are the Low Earth Orbits (LEO) up to about 2000 km, and Geosynchronous Orbits (GEO) at an altitude of around 36000 km. The impact of the debris accumulations are in principle the same in the two regions; nevertheless they require different approaches and solutions, due to the fact that the perturbations in the orbital decay due to atmospheric drag effects predominates in LEO, gravitational forces including earth’s oblateness and luni solar effects dominating in GEO are different in these two regions. In LEO it is generally known that the debris population dominates even the natural meteoroid population for object sizes 1 mm and larger. This thesis focuses the study mainly in the LEO region. Since the first satellite breakup in 1961 up to 01 January 2003 more than 180 spacecraft and rocket bodies have been known to fragment in orbit. The resulting debris fragments constitute nearly 40% of the 9000 or more of the presently tracked and catalogued objects by USSPACECOM. The catalogued fragment count does not include the much more numerous fragments, which are too small to be detected from ground. Hence in order to describe the trackable orbital debris environment, it is important to develop mathematical models to simulate the trackable fragments and later expand it to untrackable objects. Apart from the need to better characterize the orbital debris environment down to sub millimeter particles, there is also a pressing necessity of simulation tools able to model in a realistic way the long term evolution of space debris, to highlight areas, which require further investigations, and to study the actual mitigation effects of space policy measures. The present thesis has provided newer perspectives for five major issues in space debris modeling studies. The issues are (i) breakup modeling, (ii) environment modeling, (iii) evolution of the debris environment, (iv) collision probability analysis and (v) reentry prediction. The Chapter 1 briefly describes an overview of space debris environment and the issues associated with the growing space debris populations. A literature survey of important earlier work carried out regarding the above mentioned five issues are provided in the Chapter 2. The new contributions of the thesis commence from Chapter 3. The Chapter 3 proposes a new breakup model to simulate the creation of debris objects by explosion in LEO named “A Semi Stochastic Environment Modeling for Breakup in LEO” (ASSEMBLE). This model is based on a study of the characteristics of the fragments from on orbit breakups as provided in the TLE sets for the INDIAN PSLV-TES mission spent upper stage breakup. It turned out that based on the physical mechanisms in the breakup process the apogee, perigee heights (limited by the breakup altitude) closely fit suitable Laplace distributions and the eccentricity follows a lognormal distribution. The location parameters of these depend on the orbit of the parent body at the time of breakup and their scale parameters on the intensity of explosion. The distribution of the ballistic coefficient in the catalogue was also found to follow a lognormal distribution. These observations were used to arrive at the proper physical, aerodynamic, and orbital characteristics of the fragments. Subsequently it has been applied as an inverse problem to simulate and further validate it based on some more typical well known historical on orbit fragmentation events. All the simulated results compare quite well with the observations both at the time of breakup and at a later epoch. This model is called semi stochastic in nature since the size and mass characteristics have to be obtained from empirical relations and is capable of simulating the complete scenario of the breakup. A new stochastic environment model of the debris scenario in LEO that is simple and impressionistic in nature named SIMPLE is proposed in Chapter 4. Firstly among the orbital debris, the distribution of the orbital elements namely altitude, perigee height, eccentricity and the ballistic coefficient values for TLE sets of data in each of the years were analyzed to arrive at their characteristic probability distributions. It is observed that the altitude distribution for the number of fragments exhibits peaks and it turned out that such a feature can be best modeled with a tertiary mixture of Laplace distributions with eight parameters. It was noticed that no statistically significant variations could be observed for the parameters across the years. Hence it is concluded that the probability density function of the altitude distribution of the debris objects has some kind of equilibrium and it follows a three component mixture of Laplace distributions. For the eccentricity ‘e’ and the ballistic parameter ‘B’ values the present analysis showed that they could be acceptably quite well fitted by Lognormal distributions with two parameters. In the case of eccentricity also the describing parameter values do not vary much across the years. But for the parameters of the B distribution there is some trend across the years which perhaps may be attributed to causes such as decay effect, miniaturization of space systems and even the uncertainty in the measurement data of B. However in the absence of definitive cause that can be attributed for the variation across the years, it turns out to be best to have the most recent value as the model value. Lastly the same kind of analysis has also been carried out with respect to the various inclination bands. Here the orbital parameters are analyzed with respect to the inclination bands as is done in ORDEM (Kessler et al 1997, Liou et al 2001) for near circular orbits in LEO. The five inclination bands considered here are 0-36 deg (in ORDEM they consider 19-36 deg, and did not consider 0-19 deg), 36-61 deg, 61-73 deg, 73-91 deg and 91- 180 deg, and corresponding to each band, the altitude, eccentricity and B values were modeled. It is found that the third band shows the models with single Laplace distribution for altitude and Lognormal for eccentricity and B fit quite well. The altitude of other bands is modeled using tertiary mixture of Laplace distributions, with the ‘e’ and ‘B’ following once again a Lognormal distribution. The number of parameter values in SIMPLE is, in general, just 8 for each description of altitude or perigee distributions whereas in ORDEM96 it is more. The present SIMPLE model captures closely all the peak densities without losing the accuracy at other altitudes. The Chapter 5 treats the evolution of the debris objects generated by on orbit breakup. A novel innovative approach based on the propagation of an equivalent fragment in a three dimensional bin of semi major axis, eccentricity, and the ballistic coefficient (a, e, B) together with a constant gain Kalman filter technique is described in this chapter. This new approach propagates the number density in a bin of ‘a’ and ‘e’ rapidly and accurately without propagating each and every of the space debris objects in the above bin. It is able to assimilate the information from other breakups as well with the passage of time. Further this approach expands the scenario to provide suitable equivalent ballistic coefficient values for the conglomeration of the fragments in the various bins. The heart of the technique is to use a constant Kalman gain filter, which is optimal to track the dynamically evolving fragment scenario and further expand the scenario to provide time varying equivalent ballistic coefficients for the various bins. In the next chapter 6 a new approach for the collision probability assessment utilizing the closed form solution of Wiesel (1989) by the way of a three dimensional look up table, which takes only air drag effect and an exponential model of the atmosphere, is presented. This approach can serve as a reference collision probability assessment tool for LEO debris cloud environment. This approach takes into account the dynamical behavior of the debris objects propagation and the model utilizes a simple propagation for quick assessment of collision probability. This chapter also brings out a comparison of presently available collision probability assessment algorithms based on their complexities, application areas and sample space on which they operate. Further the quantitative assessment of the collision probability estimates between different presently available methods is carried out and the obtained collision probabilities are match qualitatively. The Chapter 7 utilizes once again the efficient and robust constant Kalman gain filter approach that is able to handle the many uncertain, variable, and complex features existing in the scenario to predict the reentry time of the risk objects. The constant gain obtained by using only a simple orbit propagator by considering drag alone is capable of handling the other modeling errors in a real life situation. A detailed validation of the approach was carried out based on a few recently reentered objects and comparison of the results with the predictions of other agencies during IADC reentry campaigns are also presented. The final Chapter 8 provides the conclusions based on the present work carried together with suggestions for future efforts needed in the study of space debris. Also the application of the techniques evolved in the present work to other areas such as atmospheric data assimilation and forecasting have also been suggested.

Solutions to trajectory optimization problems are carried out by the direct and indirect methods. Under broad heading of these methods, numerous algorithms such as collocation, direct, indirect and multiple shooting methods have been developed and reported in the literature. Each of these algorithms has certain advantages and limitations. For example, direct shooting technique is not suitable when the number of nonlinear programming variables is large. Indirect shooting method requires analytical derivatives of the control and co-states function and a poorly guessed initial condition can result in numerical unstable values of the adjoint variable. Multiple shooting techniques can alleviate some of these difficulties by breaking down the trajectory into several segments that help in reducing the non-linearity effects of early control on later parts of the trajectory. However, multiple shooting methods then have to handle more number of variables and constraints to satisfy the defects at the segment joints. The sie of the nonlinear programming problem in the collocation method is also large and proper locations of grid points are necessary to satisfy all the path constraints. Stochastic methods such as Genetic algorithms, on the other hand, also require large number of function evaluations before convergence. To overcome some of the limitations of the conventional methods, improved solution techniques are developed. Three improved methods are proposed for the solution of trajectory optimization problems. They are • a genetic algorithm employing dominance and diploidy concept. • a collocation method using chebyshev polynomials , and • a hybrid method that combines collocation and direct shooting technique A conventional binary-coded genetic algorithm uses a haploid chromosome, where a single string contains all the variable information in the coded from. A diploid, as the name suggests, uses pair of chromosomes to store the same characteristic feature. The diploid genetic algorithm uses a dominant map for decoding genotype into a stable, consistent phenotype. In dominance, one allele takes precedence over another. Diploidy and dominance helps in retaining the previous best solution discovered and shields them from harmful selection in a changing environment. Hence, diploid and dominance affect a king of long-term memory in the genetic algorithm. They allow alternate solutions to co-exist. One solution is expressed and the other is held in abeyance. In the improved diploid genetic algorithm, dominant and recessive genes are defined based on the fitness evaluation of each string. The genotype of fittest string is declared as the dominant map. The dominant map is dynamic in nature as it is replaced with a better individual in future generations. The concept of diploidy and dominance in the improved method mimics closer to the principles used in human genetics as compared to any such algorithms reported in the literature. It is observed that the improved diploid genetic algorithm is able to locate the optima for a given trajectory optimization problem with 10% lower computational time as compared to the haploid genetic algorithm. A parameter optimization problem arising from an optimal control problem where states and control are approximated by piecewise Chebyshev polynomials is well known. These polynomials are more accurate than the interpolating segments involving equal spaced data. In the collocation method involving Chebyshev polynomials, derivatives of two neighboring polynomials are matched with the dynamics at the nodal points. This leads to a large number of equality constraints in the optimization problem. In the improved method, derivative of the polynomial is also matched with the dynamics at the center of segments. Though is appears the problem size is merely increased, the additional computations improve the accuracy of the polynomial for a larger segment. The implicit integration step size is enhanced and overall size of the problem is brought down to one-fourth of the problem size defined with a conventional collocation method using Chebyshev polynomials. Hybrid method uses both collocation and direct shooting techniques. Advantages of both the methods are combined to give more synergy. Collocation method is used in the starting phase of the hybrid method. The disadvantage of standalone collocation method is that tuning of grid points is required to satisfy the path constraints. Nevertheless, collocation method does give a good guess required for the terminal phase of the hybrid method, which uses a direct shooting approach. Results show nearly 30% reduction in computation time for the hybrid approach as compared to a method in which direct shooting alone is used, for the same initial guess of control. The solutions obtained from the three improved methods are compared with an indirect method. The indirect method requires derivations of the control and adjoint equations, which are difficult and problem specific. Due to sensitivity of the costate variables, it is often difficult to find a solution through the indirect method. Nevertheless, these methods do provide an accurate result, which defines a benchmark for comparing the solutions obtained through the improved methods. Trajectory design and optimization of a RLV(Reusable Launch Vehicle) Demonstrator mission is considered as a test problem for evaluating the performance of the improved methods. The optimization problem is difficult than a conventional launch vehicle trajectory optimization problem because of the following two reasons. • aerodynamic lift forces in the RLV add one more dimension to the already complex launch vehicle optimization problem. • as RLV performs a sub orbital flight, the ascent phase trajectory influences the re-entry trajectory. Both the ascent and re-entry optimization problem of the RLV mission is addressed. It is observed that the hybrid method gives accurate results with least computational effort, as compared with other improved techniques for the trajectory optimization problem of RLV during its ascent flight. Hybrid method is then successfully used during the re-entry phase and in designing the feasible optimal trajectories under the dispersion conditions. Analytical solutions obtained from literature are used to compare the optimized trajectory during the re-entry phase. Trajectory optimization studies are also carried out for the off-nominal performances. Being a thrusting phase, the ascent trajectory is subjected to significant deviations, mainly arising out of solid booster performance dispersions. The performance index during rhe ascent phase is modified in a novel way for handling dispersions. It minimizes the state errors in a least square sense, defined at the burnout conditions ensure possibilities of safe re-entry trajectories. The optimal trajectories under dispersion conditions serve as a benchmark for validating the closed-loop guidance algorithm that is developed for the ascent phase flight. Finally, an on-line trajectory command-reshaping algorithm is developed which meets the flight objectives under the dispersion conditions. The guidance algorithm uses a pre-computed trajectory database along with some real-time measured parameters in generating the optimal steering profiles. The flight objectives are met under the dispersion conditions and the guidance generated steering profiles matches closely with the optimal trajectories.