Event-Driven Network Model for Space Mission Optimization with High-Thrust and Low-Thrust Spacecraft

Numerous high-thrust and low-thrust space propulsion technologies have been developed in the recent years with the goal of expanding space exploration capabilities; however, designing and optimizing a multi-mission campaign with both high-thrust and low-thrust propulsion options are challenging due to the coupling between logistics mission design and trajectory evaluation. Specifically, this computational burden arises because the deliverable mass fraction (i.e., final-to-initial mass ratio) and time of flight for low-thrust trajectories can can vary with the payload mass; thus, these trajectory metrics cannot be evaluated separately from the campaign-level mission design. To tackle this challenge, this paper develops a novel event-driven space logistics network optimization approach using mixed-integer linear programming for space campaign design. An example case of optimally designing a cislunar propellant supply chain to support multiple lunar surface access missions is used to demonstrate this new space logistics framework. The results are compared with an existing stochastic combinatorial formulation developed for incorporating low-thrust propulsion into space logistics design; our new approach provides superior results in terms of cost as well as utilization of the vehicle fleet. The event-driven space logistics network optimization method developed in this paper can trade off cost, time, and technology in an automated manner to optimally design space mission campaigns.Comment: 38 pages; 11 figures; Journal of Spacecraft and Rockets (Accepted); previous version presented at the AAS/AIAA Astrodynamics Specialist Conference, 201

Multidisciplinary Design Optimization of a Reusable Lunar Vehicle

The Lunar Orbital Platform-Gateway will be the successor to the ISS and will be placed around the Moon. To bring crew onto the lunar surface, a lunar lander must be designed and used. This work will present a system design tool for lunar landers which utilizes OpenMDAO, a multidisciplinary design optimization library. Moreover, different mission architectures will be compared independently. As a benchmark, a design for a one-stage LH2/LOX will be produced and compared to an existing design

Rapid prototyping for Martian space systems

With the clear path towards Mars for future human exploration missions, rapid prototyping tools may enhance different missions' architectural solutions. Such tools rapidly estimate mass, power and data budgets, providing quantitative figures of metrics to evaluate the most effective technical solutions in line with the stakeholders' needs. Politecnico di Torino is actively working on IDREAM an integrated framework with capabilities of sizing space systems, estimating their cost and building roadmaps for the maturation of the involved technologies. The iDREAM methodology consists of four main modules that can be used in a stand-alone mode and in an integrated activity flow, exploiting the implemented automatic connections. The first module consists of a well-structured MySQL database developed to support all the other modules, thanks to a unified connection guaranteed by an ad-hoc developed Database Management Library managing the operations of data input and output from/to the database throughout the tool modules. The second module consists of a vehicle design routine and a mission design routine, supporting the design of a new vehicle and mission concept and assessing the main performance of an already existing configuration. The third module is estimating the cost of the system. Once the design is defined, it is possible to run a subsystem-level cost estimation. Using the subsystems’ masses estimated in the design routine, the parametric cost model provides useful insights into the potential development, manufacturing, and operating costs, as well as the cost and price per flight. Eventually, the developed methodology gives the possibility to generate a technology roadmap (fourth module). Supported by a database connection, the tool estimates each technology readiness and risk assessment and indicates the necessary activities, missions, and future works. This presentation highlights the use of IDREAM to rapidly prototype Martian space systems

Multidisciplinary Design and Architecture Optimization of a Reusable Lunar Lander

With renewed interest in lunar exploration and the upcoming deployment of the lunar space station, the Lunar Orbital Platform-Gateway (LOP-G), a scientific community, is focusing on the design of a lander to bring people back to the lunar surface. This work focuses on optimizing two aspects of the lunar lander concurrently: the mission architecture and the vehicle design, often treated independently in the literature. A methodology is introduced to enumerate and preliminarily rank all possible mission architectures. The best mission architectures are then coupled with a multidisciplinary design optimization process by modeling the various components of the spacecraft and optimizing over a set of design parameters. The need for fast computational models, particularly in trajectory optimization, resulted in an analytical approximation of gravitational losses. This work resulted in a hierarchy of mission architectures that are ranked according to the average mass necessary to perform the mission. This work is intended to help a system engineer designing a lunar lander in choosing the best number of vehicles, the number of reuses, and the mission profile for his/her mission requirements

2020 NASA Technology Taxonomy

This document is an update (new photos used) of the PDF version of the 2020 NASA Technology Taxonomy that will be available to download on the OCT Public Website. The updated 2020 NASA Technology Taxonomy, or "technology dictionary", uses a technology discipline based approach that realigns like-technologies independent of their application within the NASA mission portfolio. This tool is meant to serve as a common technology discipline-based communication tool across the agency and with its partners in other government agencies, academia, industry, and across the world

Astrodynamics-optimization theory and guidance theory Research achievements review series no. 15-16

Review of research achievements in astrodynamics, optimization theory, and guidance theor

Search-based system architecture development using a holistic modeling approach

This dissertation presents an innovative approach to system architecting where search algorithms are used to explore design trade space for good architecture alternatives. Such an approach is achieved by integrating certain model construction, alternative generation, simulation, and assessment processes into a coherent and automated framework. This framework is facilitated by a holistic modeling approach that combines the capabilities of Object Process Methodology (OPM), Colored Petri Net (CPN), and feature model. The resultant holistic model can not only capture the structural, behavioral, and dynamic aspects of a system, allowing simulation and strong analysis methods to be applied, it can also specify the architectural design space. Both object-oriented analysis and design (OOA/D) and domain engineering were exploited to capture design variables and their domains and define architecture generation operations. A fully realized framework (with genetic algorithms as the search algorithm) was developed. Both the proposed framework and its suggested implementation, including the proposed holistic modeling approach and architecture alternative generation operations, are generic. They are targeted at systems that can be specified using object-oriented or process-oriented paradigm. The broad applicability of the proposed approach is demonstrated on two examples. One is the configuration of reconfigurable manufacturing systems (RMSs) under multi-objective optimization and the other is the architecture design of a manned lunar landing system for the Apollo program. The test results show that the proposed approach can cover a huge number of architecture alternatives and support the assessment of several performance measures. A set of quality results was obtained after running the optimization algorithm following the proposed framework --Abstract, page iii

The Apollo spacecraft: A chronology volume 4, 21 January 1966 - 13 July 1974

This final volume of the chronology is divided into three parts: (1) preparation for flight, the accident, and investigation; (2) recovery, spacecraft redefinition, and the first manned flight; and (3) man circles the moon, the Eagle lands, and manned space exploration. Congressional documents, official correspondence, government and contractor reports, memoranda, working papers, and minutes of meetings were used as primary sources. A relatively few entries are based on press releases and newspaper and magazine articles

A value proposition for lunar architectures utilizing on-orbit propellant refueling

In 2004, President Bush addressed the nation and presented NASA's new vision for space exploration. This vision included the completion of the International Space Station, the retirement of the Space Shuttle, the development of a new crew exploration vehicle, and the return of humans to the moon by 2020. NASA's Exploration Systems Architecture Study (ESAS) produced a transportation architecture for returning humans to the moon affordably and safely. This architecture requires the development of two new Shuttle-derived launch vehicles, an in-space transportation vehicle, a lunar descent and landing vehicle, and a crew exploration vehicle for human transportation. The development of an in-space propellant transfer capability could greatly improve the performance, cost, mission success, and mission extensibility of the overall lunar architecture, providing a more optimal solution for future exploration missions. The work done in this thesis will analyze how this new capability could affect the current NASA lunar architecture, and will outline the value proposition of propellant refueling to NASA. A value proposition for propellant refueling will be provided to establish why an architecture that utilizes propellant refueling is better equipped to meet the goals of the Vision for Space Exploration than the current baseline design. The primary goal addressed in this research is the development of a sustainable and affordable exploration program. The value proposition will outline various refueling strategies that can be used to improve each of the architecture Figures of Merit. These include a decrease in the Life Cycle Cost of both the lunar and Mars exploration campaigns, the ability to more than double the mission payload that can be delivered to the lunar surface during cargo missions, improving the probability of successfully completing each lunar mission, decreasing the uncertainty, and therefore risk, experienced during the development process, and improving the extensibility of the exploration architecture by utilizing a greater portion of the lunar program for future crewed mission. The ability to improve these Figures of Merit provides NASA with a more valuable architecture because NASA is able to achieve a greater return on its large initial investment.Ph.D.Committee Chair: Wilhite, Alan; Committee Member: Bishop, Carlee; Committee Member: Chytka, Trina; Committee Member: Schrage, Daniel; Committee Member: Stanley, Dougla