Space Mission Analysis & Design

A new approach is proposed for systematic detection and refinement of natural connections EML12 of the Earth-Moon system and SEML12 of Sun-Earth-Moon. It is structured around the Quasi-Bircircular Problem, a restricted coherent and periodic four-body dynamical model of the Sun-Earth-Moon system. The dynamics about the Libration points are described by high-order periodic semi-analytical expansions obtained via the parametrization method.

Several broad search strategies were considered. These were coupled with three guiding philosophies. First, the one relied on most heavily, was the creation of ‘long-chain backbones,’ that is, long sequences of asteroid rendezvous by one probe. The Mothership and other probe trajectories were then built up, in that order, based on the long-chain backbone. The second and lesser used approach was to design first Mothership trajectories, a ‘Mothership backbone,’ wherein the mother would drop-off probes at a series of asteroids, followed by probe trajectories starting at these asteroids and returning to the mother at a final asteroid. The third philosophy was that all of these chains would be initially designed assuming the Mothership would rendezvous with asteroids for probe pick-up and drop-off. Once good candidates were found, this assumption was lifted and separation and rejoining of mother and probes was permitted to occur away from asteroids in order to boost the mass performance ...

Rather than unfolding evenly, the universe evolves in pulses—leaps of increasing complexity that mark its deep structure. This work introduces a logarithmic model of astronomical time, charting five major nodes in the universe's evolution. Each pulse represents a threshold: from formless beginnings to galaxies, from planetary habitability to life itself.

The First Node (~32 Gya) is speculative, contemplating a quantum reality before the Big Bang—suggested by the presence of mature galaxies near the observable origin. The Second Node (~16 Gya) marks—within 25% log distance—the formation of galaxies and large-scale cosmic structure. The Third Node (~8 Gya) aligns with the emergence of interactive, layered rocky planets capable of supporting complex chemistry. The Fourth Node (~4 Gya) coincides with the emergence of living matter—a quantum leap in the universe's capacity to self-organize. The Fifth Node (~2 Gya) captures a triple transformation: the oxygenation of Earth's atmosphere, the full mobilization of global plate tectonics, and the radical complexification of life with the emergence of symbiotic eukaryotic cells—foundational for multicellular life to come.

At the heart of this model is the recognition that time is not merely a backdrop, but a structure that reveals order—where major events cluster in patterns visible only through logarithmic scaling. This approach not only maps what is known, but frames what remains to be discovered. By drawing connections between the astronomical and the biological, it offers a unified perspective on how complexity unfolds across the cosmos.

This theoretical proposal presents a comprehensive axiomatic framework for cascade-enhanced electric propulsion systems, specifically analyzing the mathematical foundations underlying the HELIOS-ION triple-source concept. Through rigorous derivation from first principles, we establish fundamental performance theorems governing integrated solar-hydrogen-ion propulsion architectures. The central theoretical contribution is the formalization of cascade efficiency mathematics and the derivation of scaling laws for multi-source synergistic propulsion systems. While speculative in nature, this framework provides mathematical rigor for evaluating the theoretical limits and performance characteristics of complex integrated propulsion concepts.

This paper presents a comprehensive theoretical model for the HELIOS-ION system, a pioneering sustainable propulsion technology that integrates solar photovoltaics, green hydrogen fuel cells, and noble gas ion propulsion in a closed-loop cycle for deep space exploration missions. Drawing from energy systems engineering, plasma physics, and spacecraft propulsion theory, the design features a cascading energy conversion mechanism that achieves unprecedented specific impulse (Isp > 10,000 seconds) while maintaining continuous operation through renewable energy sources. The central innovation is the "Master Propulsion Equation" for thrust efficiency: η_prop = η_sys × [(P_solar × η_pv × η_cap) + (P_h2 × η_fc)] / (ṁ × ve) × Γ_cascade, incorporating a Cascade Efficiency Factor that demonstrates non-linear performance gains over conventional chemical or electric propulsion systems. Material specifications leverage next-generation technologies including oxide dispersion strengthened (ODS) alloys for plasma-exposed components and high-temperature superconductors (HTS) for magnetic field generation. The system offers a paradigm shift toward sustainable, high-efficiency space propulsion with virtually unlimited operational duration, enabling missions to the outer solar system and beyond.

Between 2000 and 2024, a large number of small satellite missions fell short of their goals, with NASA pointing to structural and integration issues as common causes. Building satellites faster and at lower cost has become a major goal, especially as space systems grow more complex. Modular designs have emerged as one way to meet this demand, but the lack of reliable, reusable structural connections has limited progress. To better understand the trade-offs, this work looked at four connection methods for CubeSats: solenoid latches, rack systems, Wedge-Lok clamps, and screw fittings using L-shaped rails. Each one was reviewed using weighted criteria such as readiness for flight, expected weak points, physical size, and assembly ease. The screw and Wedge-Lok types came out ahead, mostly because of their simplicity and proven use in past missions. They also show promise for teams looking to simulate system performance before launch. Designs that allow lastminute changes, support system integration, and enable compatibility with digital models are especially useful as engineering shifts toward virtual prototyping and model-based development. The process used here can help teams decide on mechanical interfaces based on actual performance needs, not just legacy or convenience. What sets this work apart is the clear method it provides for selecting structural options that match modern space project demands. The main contribution is a flexible, criteria-driven approach for choosing CubeSat interface hardware suited to modular builds and digital system modeling.

The term Weak Stability Boundary (WSB) is related to a region of stable motion around the second primary of a circular restricted three-body problem (CR3BP). Previous work on this subject has shown that, at a given energy level, the boundaries of such region are provided by the stable manifolds of central objects of the L1 and L2 libration points, i.e., the two planar Lyapunov orbits (PLOs). This offers a natural dynamical channel between the Earth's vicinity and the Sun-Earth libration points L1 and L2. Furthermore, it has been shown (and successfully employed to design low-energy spacecraft lunar transfers) that the Sun-Earth L2 central unstable manifolds can be linked, through an heteroclinic connection, to the central stable manifolds of the L2 point in the Earth-Moon three-body problem. The aim of the present study is to clarify the relationship between the low-energy Earth-to-Moon transfers (LETs) and the dynamics of the phase space points that populate the WSB region arou...

The Ducci Unified Spectral Theory (DUST) proposes that the so-called fundamental constants of nature are not immutable but evolve with the vacuum's microstructure over cosmic time. A key prediction is that the fine-structure constant, α, differed measurably in the early universe. Here we report the first targeted experimental test of this claim using a custom Python analysis pipeline and publicly available James Webb Space Telescope (JWST) spectra. We measured finestructure splittings of the [O III] doublet in 20 high-redshift galaxies (4.9 ¡ z ¡ 9.5). A simple cosmological-evolution model of α was decisively falsified, but the data revealed a strong, monotonic correlation between redshift and the Observer Effect of Duality predicted by the refined DUST model. This correlation provides the first quantitative evidence for DUST's two-component prediction: a cosmological drift in α combined with an environment-dependent modulation. Our results constitute a preliminary but compelling validation of the DUST framework.

The concepts, operation problems and mathematical model of solar and electromagnetic sails were investigated. A technical solution to these problems has been proposed. Concept of the Space Reusable Transport Complex based on solar and electromagnetic sails has been proposed. Based on transformable truss structures and compact space nuclear reactors Basic Orbital Station and reusable interplanetary space tugs of three types with solar and electromagnetic sails were developed. The prospects for the development of the project and its use have been studied.

The design of the prototype of the Universal Research Planetary Rover “Leaving a Mark LM-8” has been developed. The problems of planetary rover operation, research objects and equipment for the functioning of the planetary rover and conducting research are considered. The existing technical solutions have been studied. Adaptive wheels with superelastic non-pneumatic tires of variable stiffness have been developed. The composition of the case materials has been selected. The necessary complex of scientific equipment is proposed. Using 3D-modeling in the computer-aided design system «Kompas-3D» design engineering models were also developed, made on a scale of 1:9.31 using additive technologies and laser cutting technologies. Design engineering model’s Remote and Automated Control Systems were developed and tested. Successful tests of design engineering models have been carried out.

In 2011, the Keck Institute for Space Studies hosted the Caltech Space Challenge, a week long workshop/competition directed towards the President's initiative of sending astronauts to an asteroid by 2025. Two teams composed of 16 students each, representing 12 different nations, competed to prepare a mission proposal by the end of the week. This report highlights some of the work done by Team Voyager. Not only is this work useful in showing that a manned mission to a Near-Earth Object is feasible by 2025, but it also demonstrates the utility of intense, relatively short student competitions. This study is an outline of Vault-1, a proposed human mission to a Near-Earth Object. In addition to continuing human exploration, Vault-1 aims to make new discoveries about the origins of the Solar System, to develop technologies geared towards deep space exploration and a manned Mars mission, and to gain critical knowledge and experience to better protect Earth from future asteroid impacts. The primary target of this endeavor is 1999AO10, an asteroid that is larger than 30 m that also has an achievable mission duration of less than 200 days. 2000SG344 is a viable secondary target. Vault-1 will nominally carry 3 crew members to 1999AO10; after 14 days at the asteroid, the astronauts will return safely to the Earth with samples from the asteroid. An official copy of the report Team Voyager created during the competition can be found at

A multifunctional hot structure heatshield concept is being developed to provide technology enhancements with significant benefits compared to the current state-of-the-art heatshield technology. These benefits can potentially enable future planetary missions. The concept is unique in integrating the function of the thermal protection system with the primary load carrying structural component. An advanced carbon-carbon material system has been evaluated for the load carrying structure, which will be utilized on the outer surface of the heatshield, and thus will operate as a hot structure exposed to the severe aerodynamic heating associated with planetary entry. Flexible, highly efficient blanket insulation is sized for use underneath the hot structure to maintain required operational internal temperatures. The approach followed includes developing preliminary designs to demonstrate feasibility of the concept and benefits over a traditional, baseline design. Where prior work focused on a concept for an Earth entry vehicle, the current efforts presented here are focused on developing a generic heatshield model and performing a trade study for a Mars entry application. This trade study includes both structural and thermal evaluation. The results indicate that a hot structure concept is a feasible alternative to traditional heatshields and may offer advantages that can enable future entry missions.

Currently, an urgent task in space exploration is the research of planets, their moons and other solid space bodies. In this paper the prototype of the Universal Research Planetary Rover «Leaving a Mark LM-8» for the planetary research has been developed. The research object and equipment for conducting research are considered. The concept of the planetary rover’s control system has been developed. The necessary complex of scientific equipment for the research of Mars, Titan and exoplanets which will be able to conduct comprehensive researches of the surface, soil, atmosphere and various conditions on the planet, as well as be able to search for water and biosignatures – signs of a possible past and present life has been proposed. 3D models of the robotic arm complex and the deep soil-sampling tools for conducting soil research have been developed. Support systems for scientific researchers, energy supply and dust, soiling and drops removing worked out. Payload options are proposed.

The concepts, operation problems and mathematical model of solar and electromagnetic sails were investigated. A technical solution to these problems has been proposed. Concept of the  Space Reusable Transport Complex based on solar and electromagnetic sails has been proposed. Based on transformable truss structures and compact space nuclear reactors Basic Orbital Station and reusable interplanetary space tugs of three types with solar and electromagnetic sails were developed. The prospects for the development of the project and its use have been studied.

The design of the prototype of the Universal Research Planetary Rover “Leaving a Mark LM-8” has been developed. The problems of planetary rover operation, research objects and equipment for the functioning of the planetary rover and conducting research are considered. The existing technical solutions have been studied. Adaptive wheels with superelastic non-pneumatic tires of variable stiffness have been developed. The composition of the case materials has been selected. The necessary complex of scientific equipment is proposed. Using 3D-modeling in the computer-aided design system «Kompas-3D» design engineering models were also developed, made on a scale of 1:9.31 using additive technologies and laser cutting technologies. Design engineering model’s Remote and Automated Control Systems were developed and tested. Successful tests of design engineering models have been carried out.

At the present time, the search for the knowledge of our Solar System continues effective. NASA's Solar System Exploration theme listed a Neptune mission as one of its top priorities for the mid-term (2008)(2009)(2010)(2011)(2012)(2013). From the technical point of view, gravity assist is a proven technique in interplanetary exploration, as exemplified by the missions Voyager, Galileo, and Cassini. Here, a mission to Neptune for the mid-term (2008-2020) is proposed, with the goal of studying several schemes for the mission. A direct transfer to Neptune is considered and also Venus, Earth, Jupiter, and Saturn gravity assists are used for the transfer to Neptune, which represent new contributions for a possible real mission. We show several schemes, including or not the braking maneuver near Neptune, in order to find a good compromise between the DV and the time of flight to Neptune. After that, a study is made to take advantage of an asteroid flyby opportunity, when the spacecraft passes by the main asteroid belt. Results for a mission that makes an asteroid flyby with the asteroid 1931 TD3 is shown.

At the present time, the search for the knowledge of our Solar System continues effective. NASA's Solar System Exploration theme listed a Neptune mission as one of its top priorities for the mid-term (2008)(2009)(2010)(2011)(2012)(2013). From the technical point of view, gravity assist is a proven technique in interplanetary exploration, as exemplified by the missions Voyager, Galileo, and Cassini. Here, a mission to Neptune for the mid-term (2008-2020) is proposed, with the goal of studying several schemes for the mission. A direct transfer to Neptune is considered and also Venus, Earth, Jupiter, and Saturn gravity assists are used for the transfer to Neptune, which represent new contributions for a possible real mission. We show several schemes, including or not the braking maneuver near Neptune, in order to find a good compromise between the DV and the time of flight to Neptune. After that, a study is made to take advantage of an asteroid flyby opportunity, when the spacecraft passes by the main asteroid belt. Results for a mission that makes an asteroid flyby with the asteroid 1931 TD3 is shown.

In forthcoming decades, coverage in the wavelength regimes that are either inaccessible or compromised from the ground will be degraded as the Great Observatories and other facilities age or are decommissioned. This reduction in capability will be accompanied by a loss in the community’s ability to study astrophysical phenomena at multiple wavelength and temperature regimes, a key to rapid progress, and by an erosion in the technical and scientific expertise in the wavelength regimes that have become out of reach. Expansions of discovery space resulting from new capabilities in some wavelength regimes will be limited by the lack of commensurate data in other regimes. To ensure that multi-wavelength capabilities are maintained, we recommend that NASA consider panchromatic coverage as an explicit strategic goal. Based on the experience of the Great Observatories, a panchromatic goal can be achieved with a mixture of flagship and probe scale missions with lifetimes that exceed a decade...

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Technology Alignment and Portfolio Prioritization (TAPP) is a method being developed by the Advanced Concepts Office, at NASA Marshall Space Flight Center. The TAPP method expands on current technology assessment methods by incorporating the technological structure underlying technology development, e.g., organizational structures and resources, institutional policy and strategy, and the factors that motivate technological change. This paper discusses the methods ACO is currently developing to better perform technology assessments while taking into consideration Strategic Alignment, Technology Forecasting, and Long Term Planning.

len, Jr., A. I. Alunni, M. J. Amato, D. H. Atkinson, B. J. Bienstock, J. R. Cruz, R. A. Dillman, A. D. Cianciolo, J. O. Elliott, J. D. Feldman, M. D. Hofstadter, K. M. Hughes, M. A. Lobbia, G. C. Marr, F. S. Milos, K. H. Peterson, D. K. Prabhu, and T. R. White. NASA Ames Research Center, M/S 230-3, Moffett Field, CA 94035, USA (helen.hwang@nasa.gov), AMA, Inc. at NASA ARC, NASA Goddard Space Flight Center, Jet Propulsion Laboratory, NASA Langley Research Center, NASA Ames Research Center.

This NRC Decadal Survey white paper, provided by the thermal protection technology community, is a general assessment of the current capability of thermal protection systems (TPS) with respect to the scientific exploration of Venus as well as anticipated TPS requirements in support of future Venus missions 1,3,5. The paper begins with a brief history of

Over time, complex systems such as the Milky Way galaxy are constantly seeking solutions to their deficiencies, shortcomings, needs in order to maintaining survival and continuity of sustainability and continuous development. These systems, with continuous self-referral using available resources and existing capabilities, strive to achieve natural stability and adapt to their environment by applying efficient rules with a systematic structure, and stable principles, along with methodical performance. This complex procedure, in a continuous cycle process of emergence, nurturing procedure, and transformational pattern, demonstrates the ability of complex systems to naturally adapt to environmental changes and continuously find solutions to maintaining survival and continuity of sustainability and continuous development.

Gateway Earth is proposed as modular space access architecture, operating a combined governmental space station and commercial space hotel located in the geostationary orbit [1, 2]. This location, close to the edge of the Earth's "gravity well", is ideal for robotic and crewed interplanetary spacecraft to dock as they depart for, or return from, any Solar System destinations. Additionally, assembling interplanetary craft, almost certainly including in-situ (additive) manufactured components, at this location would avoid these vehicles having to withstand the rigors of launch and re-entry through Earth's atmosphere. Moreover, space tourism revenues will provide a significant part of the funding needed to both build the complex and supply the regular reusable tug service via low-earth orbit [3]. Various elements of the architecture are being developed independently by a whole range of different space engineering firms and national and international agencies; some large, and others small and entrepreneurial in nature. Our aim is to synthesize all these disparate activities, and have them focus on making the overall Gateway Earth concept possible and deliverable in the mid-term future [4]. This paper is providing a status update on Gateway Earth Development Group's progress to date and invites feedback on key modules of the architecture as well as Gateway Earth's overall development and operational strategy.

Gateway Earth is proposed as modular space access architecture, operating a combined governmental space station and commercial space hotel located in the geostationary orbit [1, 2]. This location, close to the edge of the Earth's "gravity well", is ideal for robotic and crewed interplanetary spacecraft to dock as they depart for, or return from, any Solar System destinations. Additionally, assembling interplanetary craft, almost certainly including in-situ (additive) manufactured components, at this location would avoid these vehicles having to withstand the rigors of launch and re-entry through Earth's atmosphere. Moreover, space tourism revenues will provide a significant part of the funding needed to both build the complex and supply the regular reusable tug service via low-earth orbit [3]. Various elements of the architecture are being developed independently by a whole range of different space engineering firms and national and international agencies; some large, and others small and entrepreneurial in nature. Our aim is to synthesize all these disparate activities, and have them focus on making the overall Gateway Earth concept possible and deliverable in the mid-term future [4]. This paper is providing a status update on Gateway Earth Development Group's progress to date and invites feedback on key modules of the architecture as well as Gateway Earth's overall development and operational strategy.

Future in situ space plasma investigations will likely involve spatially distributed observatories comprised of multiple spacecraft, beyond the four and five spacecraft configurations currently in operation. Inferring the magnetic field structure across the observatory, and not simply at the observation points, is a necessary step towards characterizing fundamental plasma processes using these unique multi-point, multi-scale data sets. We propose improvements upon the classic first-order reconstruction method, as well as a second-order method, utilizing magnetometer measurements from a realistic nine-spacecraft observatory. The improved first-order method, which averages over select ensembles of four spacecraft, reconstructs the magnetic field associated with simple current sheets and numerical simulations of turbulence accurately over larger volumes compared to second-order methods or first-order methods using a single regular tetrahedron. Using this averaging method on data sets w...

In 2007, the Committee on Meeting the Workforce Needs for the National Vision for Space Exploration published findings related to age and skills of the current National Aeronautics and Space Administration (NASA) workforce and projected potential expertise shortages as a result of retirement in the 2014-2015 time frame. In addition, the expanding commercial space industry in both the United States and Europe will likely create further demand for space experts in engineering and a variety of related fields. Although NASA contributes $162 million in funding for education programs annually, those programs target kindergarten through grade 12, not collegiate-level programs. Further, few aeronautical/aerospace departments focused on education related to the development of space technologies, a discipline known as astronautics, exist in the US. In 2009, Doule and Peeters, Professors at the International Space University, sought to determine the need for space-focused knowledge and skills ...

With growing interest in low-cost, high performance and short time-to-flight satellites, the idea of using multipurpose satellite platforms has drawn many attentions. However, under certain conditions in which the required capability of a mission is slightly more than the capabilities of a specified variant of a multi-purpose platform, it must jump to the next higher capability variant. Correspondingly, lots of unnecessary performance or capability might be imposed. In this paper, the main goal is to minimize the wasted performance in the design of an Earth Observation (EO) satellite based on a multi-purpose platform. To this end, a dynamic simulation-based model has been developed with the capability of simulating the satellite performance characteristics, EO mission requirements and supportable performance by the platform under various circumstances and throughout the satellite lifetime. To minimize the wasted performance we face with an optimization problem containing a complicated non-linear, non-convex and multi-modal design space which is enveloped by constraints of the mission requirements and supportable performance of the platform. A novel criterion as an objective function has been introduced aiming at the incompatibility reduction between the capabilities of a certain multi-purpose platform variant and the EO mission requirements. This objective function considers all the performance variations during the entire mission lifetime rather than solely the worst case. Through this, the mission and orbital characteristics have been determined by which there would be no need to jump to the higher performance variant in order to satisfy the EO mission requirements.

Recently, manifold dynamics has assumed an increasing relevance for analysis and design of low-energy missions, both in the Earth-Moon system and in alternative multibody environments. This work proposes and describes an intuitive polyhedral interpolative approach for each state component associated with manifold trajectories, both in two and in three dimensions. An adequate grid of data, coming from the numerical propagation of a finite number of manifold trajectories, is employed. Accuracy of this representation is evaluated with reference to the invariant manifolds associated with a two-dimensional Lyapunov orbit and a three-dimensional Halo orbit, and is proven to be satisfactory, with the exclusion of limited regions of the manifolds. As a first, preliminary application, the polyhedral interpolation technique allows identifying the orbits in the proximity of the interior collinear libration point as either asymptotic, transit, or bouncing trajectories. Then, two applications to orbital maneuvering are addressed. First, the globally optimal two-impulse transfer between a specified low Earth orbit and a Lyapunov orbit (through its stable manifold) is determined. Second, the minimum-time low-thrust transfer from the same terminal orbits is found using again the stable manifold. These applications prove the effectiveness of the polyhedral interpolative technique and represent the premise for its application also to different problems involving invariant manifold dynamics.

The goal of the SINPLEX project is to develop an innovative solution to significantly reduce the mass of the navigation subsystem for exploration missions which include landing and/or rendezvous and capture phases. The system mass is reduced while still maintaining good navigation performance as compared to a conventional modular system. This is done by functionally integrating the navigation sensors, using microand nanotechnology to miniaturize electronics and fusing the sensor data within a navigation filter to improve navigation performance. A breadboard system was build including a navigation computer, IMU, laser altimeter/range finder, star tracker and navigation camera and has space for the redundant counterparts. Testing using the TRON hardware-in-the-loop testbench is ongoing. This

Flexible Ablators: Applications and Arcjet Testing James O. Arnold1, Ethiraj Venkatapathy1, ,Robin Beck1 Kathy M. McGuire1, Dinesh K. Prabhu2 and Sergey Gorbunov3 Abstract for the Eight International Planetary Probe Workshop June 8‐10, 2011 Portsmouth Va The ...

The ongoing revolution of space access by means of cost-effective and highly performant small satellites, in particular CubeSats, drives the development of a vast host of new and increasingly complex applications. However, the use of small satellites for ambitious missions brings its own challenges with thermal breakdown as one of the key contributors to component failure. We have therefore developed a lightweight approach specifically tailored to the thermal modeling of small satellites to localize and mitigate the associated thermal risks while maintaining the flexibility and low resource footprint necessary to be applicable in the framework of small satellite mission design. At the core of the methodology, we implemented an experimental database of physical parameters as well as highly parallelized numerical analysis methods. In particular, we introduce an efficient way to determine view factors for insolation and internal radiative energy transport based on a hemicube radiosity ...

This report provides a summary of the work performed under NIAC Phase I award NNX15AL86G entitled "CubeSat with Nanostructured Sensing Instrumentation for Planetary Exploration". The objective of this research is to investigate the feasibility of an innovative, low cost, CubeSat based planetary mission concept for in situ "ground truth" analysis of small asteroids and comets. The project includes an instrument study and a mission/spacecraft design study. The instrument study concerns with the development of a new TiO 2 nanotube sensor with integrated compound semiconductor nanowires to determine surface composition element via neutron activated analysis (NAA). The mission/spacecraft design study concerns with the development of CubeSat based lander to small asteroids and comets. The Phase I study suggests that our concept is feasible and could provide significant benefit to NASA's future planetary missions. This research was carried out at the

This work shows that a class of astrodynamics problems subject to mission constraints can be efficiently solved using the Theory of Functional Connections (TFC) mathematical framework by a specific change of coordinates. In these problems, the constraints are initially written in nonlinear and coupled mathematical forms using classical rectangular coordinates. The symmetries of the constrained problem are used to select a new system of coordinates that transforms the nonlinear constraints into linear. This change of coordinates is also used to isolate the components of the constraints. This way the TFC technique can be used to solve the ordinary differential equations governing orbit transfer problems subject to mission constraints. Specifically, this paper shows how to apply the change of coordinates method to the perturbed Hohmann-type and the one-tangent burn transfer problems.

The determination of a specific orbit and the procedure to calculate orbital maneuvers for artificial satellites are problems of extreme importance in the study of orbital mechanics. Therefore, the transferring problem of a spaceship from one orbit to another, and the attention to this subject has increased during the last years. Many applications can be found in several space activities, for example, to put a satellite in a geostationary orbit, to change the position of a spaceship, to maintain a specific satellite's orbit, in the design of an interplanetary mission, and others. The orbit and the general data of the Brazilian Satellite SCD-1 (Data Collecting Satellite) will be used as example in this paper. It is the first satellite developed entirely in Brazil, and it remains in operation to this date. SCD-1 was designed, developed, built, and tested by Brazilian scientists, engineers, and technicians working at INPE (National Institute for Space Research) and in Brazilian Industries. During its lifetime we will study its orbital behavior and we will perform some orbital maneuvers that could be necessary, being this one either an orbital transferring, or just to make periodical corrections. The purpose of the transferring problem is to change the position, velocity and the satellite's mass to a new pre-determined state. This transfer can be totally linked (in the case of "Rendezvous") or partially free (free time, free final velocity, etc). In the global case, the direction, the orientation and the magnitude of the thrust to be applied must be chosen, respecting the equipment's limit. In order to make this transferring, either sub-optimal or optimal maneuvers may be used. In the present study, only the sub-optimal will be shown, since we want to study an algorithm for this type of maneuver. Hence, this method will simplify the direction of thrust application, to allow a fast calculation that may be used in real time, with a very fast processing. The thrust application direction to be applied will be assumed small and constant, and the purpose of this paper is to find the time interval that the thrust is applied. This paper is basically divided into three parts: during the first one the sub-optimal maneuver is explained and detailed, the second presents the Satellite SCD-1, and finally the last part shows the results using the sub-optimal maneuver applied to the Brazilian Satellite.