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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The overarching objective of space mission design is to tackle complex problems producing better results, and faster. In developing the methods and tools to fulfill this objective, the user interacts with the different layers of a computing system.
In recent years, conceptual-phase (proposal level) design of space missions has been improved considerably. Team structures, tool linkage, specialized facilities known as design centers and scripted processes have been demonstrated to cut proposal-level engineering design time from a few months to a few weeks.
Based on an empirical analysis of conceptual space mission design at the JPL and NASA sites, the following are a set of factors that have been determined to lead to potential risk.
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Distributed Space Missions (DSMs) are gaining momentum in their application to earth observation missions owing to their unique ability to increase observation sampling in multiple dimensions. DSM design is a complex problem with many design variables, multiple objectives determining performance and cost and emergent, often unexpected, behaviors. There are very few open-access tools available to explore the tradespace of variables, minimize cost and maximize performance for pre-defined science goals, and therefore select the most optimal design. This paper presents a software tool that can multiple DSM architectures based on pre-defined design variable ranges and size those architectures in terms of predefined science and cost metrics. The tool will help a user select Pareto optimal DSM designs based on design of experiments techniques. The tool will be applied to some earth observation examples to demonstrate its applicability in making some key decisions between different performance metrics and cost metrics early in the design lifecycle.
STI is for a presentation being given to visitors coming to NASA Ames from the United Arab Emirates.
In this paper we describe design centers and show how it has produced remarkable decreases in time and expense of creating preliminary designs.
Habitability is a fundamental component of any long-duration human habitat. Due to the pressures on the crew and the criticality of their performance, this is particularly true of habitats or vehicles proposed for use in any human space mission of duration over 30 days. This paper, the second of three on this subject, will focus on evaluating all the vehicles currently under consideration for the Mars Design Reference Mission through application of metrics for habitability (proposed in a previous paper, see references Adams/McCurdy 1999).
The advancement of solar-electric propulsion (SEP) technologies and larger, light-weight solar arrays offer a tremendous advantage to Mars orbiters in terms of both mass and timeline flexibility. These advantages are multiplied for round-trip orbiters (e.g. potential Mars sample return) where a large total Delta V would be required. In this paper we investigate the mission design characteristics of mission concepts utilizing various combinations and types of SEP thrusters, solar arrays, launch vehicles, launch dates, arrival dates, etc. SEP allows for greater than 50% more mass delivered and launch windows of months to years. We also present the SEP analog to the ballistic Porkchop plot - the "Bacon" plot.
The invariant manifold structures of the collinear libration points for the spatial restricted three-body problem provide the framework for understanding complex dynamical phenomena from a geometric point of view. In particular, the stable and unstable invariant manifold 'tubes' associated to libration point orbits are the phase space structures that provide a conduit for orbits between primary bodies for separate three-body systems. These invariant manifold tubes can be used to construct new spacecraft trajectories, such as 'Petit Grand Tour' of the moons of Jupiter. Previous work focused on the planar circular restricted three-body problem. The current work extends the results to the spatial case.
Modern Systems Engineering activities for robotic science missions face increased complexity due to evolving measurement requirements, increased collaboration amongst stakeholders and increased collaboration between human and robotic systems. While NASA has employed standard process frameworks for project management and systems engineering for years, it has not yet established an architecture framework (AF) by which its mission systems are described. While an architecture framework is not a necessary component of an organization's operations, the value of a specified AF greatly enhances an organization's ability to define systems consistently and aid in communication across project and organizational boundaries. The current effort identifies an approach to establishing a Space Mission Architecture Framework (SMAF), an AF with roots in ISO 42010 (Systems and Software Engineering-Architecture Description), NASA Procedural Requirements (NPR) 7120.5 (NASA Space Flight Program and Project Management Requirements) and 7123.1B (NASA Systems Engineering Processes and Requirements). The heart of the AF lies in its viewpoints and work products, artifacts that represent a set of information from the viewpoint of a particular stakeholder. This effort articulates the needs, goals and objectives that the SMAF addresses, as well as the approach to creating the framework and establishing the various work products. A full set of work products, sufficient to satisfy the Mission System reporting requirements of NPR 7120/7123 at Key Decision Point (KDP) A is identified in this paper.
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