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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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At least 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

Making the Case for Reusable Booster Systems: The Operations Perspective

Presentation to the Aeronautics Space Engineering Board National Research Council Reusable Booster System: Review and Assessment Committee. Addresses: the criteria and assumptions used in the formulation of current RBS plans; the methodologies used in the current cost estimates for RBS; the modeling methodology used to frame the business case for an RBS capability including: the data used in the analysis, the models' robustness if new data become available, and the impact of unclassified government data that was previously unavailable and which will be supplied by the USAF; the technical maturity of key elements critical to RBS implementation and the ability of current technology development plans to meet technical readiness milestones.

reusable launch vehicle↗
NASA NTRS1973

Apollo experience report: Evolution of the rendezvous-maneuver plan for the lunar-landing missions

The evolution of the nominal rendezvous-maneuver plan for the lunar landing missions is presented along with a summary of the significant development for the lunar module abort and rescue plan. A general discussion of the rendezvous dispersion analysis that was conducted in support of both the nominal and contingency rendezvous planning is included. Emphasis is placed on the technical developments from the early 1960's through the Apollo 15 mission (July to August 1971), but pertinent organizational factors also are discussed briefly. Recommendations for rendezvous planning for future programs relative to Apollo experience also are included.

Alexander, J. D.↗
NASA NTRS1988

Development of an expert planning system for OSSA

This paper presents concepts related to preliminary work for the development of an expert planning system for NASA's Office for Space Science and Applications (OSSA). The expert system will function as a planner's decision aid in preparing mission plans encompassing sets of proposed OSSA space science initiatives. These plans in turn will be checked against budgetary and technical constraints and tested for constraint violations. Appropriate advice will be generated by the system for making modifications to the plans to bring them in line with the constraints. The OSSA Planning Expert System (OPES) has been designed to function as an integral part of the OSSA mission planning process. It will be able to suggest a best plan, be able to accept and check a user-suggested strawman plan, and should provide a quick response to user request and actions. OPES will be written in the C programming language and have a transparent user interface running under Windows 386 on a Compaq 386/20 machine. The system's sorted knowledge and inference procedures will model the expertise of human planners familiar with the OSSA planning domain. Given mission priorities and budget guidelines, the system first sets the launch dates for each mission. It will check to make sure that planetary launch windows and precursor mission relationships are not violated. Additional levels of constraints will then be considered, checking such things as the availability of a suitable launch vehicle, total mission launch mass required vs. the identified launch mass capability, and the total power required by the payload at its destination vs. the actual power available. System output will be in the form of Gantt charts, spreadsheet hardcopy, and other presentation quality materials detailing the resulting OSSA mission plan.

Groundwater, B.↗
NASA NTRS2001

Telemetry Tracking & Control (TT&C) - First TDRSS, then Commercial GEO & Big LEO and Now Through LEO

The advent of low earth orbit (LEO) commercial communication satellites provides an opportunity to dramatically reduce Telemetry, Tracking and Control (TT&C) costs of launch vehicles, Unpiloted Aerial Vehicles (UAVs), Research Balloons and spacecraft by reducing or eliminating ground infrastructure. Personnel from the Goddard Space Flight Center's Wallops Flight Facility (GSFC\WFF) have successfully used commercial Geostationary Earth Orbit (GEO) and Big LEO communications satellites for Long Duration Balloon Flight TT&C. The Flight Modem is a GSFC\WFF Advanced Range Technology initiative (ARTI) designed to streamline TT&C capability in the user community of these scientific data gathering platforms at low cost. Making use of existing LEO satellites and adapting and ruggedized commercially available components; two-way, over the horizon communications may be established with these vehicles at great savings due to reduced infrastructure. Initially planned as a means for permitting GPS data for tracking and recovery of sounding rocket and balloon payloads, expectations are that the bandwidth can soon be expanded to allow more comprehensive data transfer. The system architecture which integrates antennas, GPS receiver, commercial satellite packet data modem and a single board computer with custom software is described and technical challenges are discussed along with the plan for their resolution. A three-phase testing and development plan is outlined and the current results are reported. Results and status of ongoing flight tests on aircraft and sounding rockets are reported. Future applications on these platforms and the potential for satellite support are discussed along with an analysis of cost effectiveness of this method vs. other tracking and data transmission schemes.

Morgan, Dwayne R.↗
NASA NTRS2018

Improving Reliability and Maintainability (R&M) in Space Life Support

This paper considers how to improve the reliability and maintainability (R&M) of future NASA space life support systems. If these systems are procured under an industry contract, defining the R&M requirements would take precedence over providing technical guidance on designing the system. Imposing a specific R&M design could be over constraining. However, the mission may define the overall R&M approach, as the International Space Station (ISS) did by requiring Orbital Replacement Units (ORUs). Before defining the R&M requirements for the next mission, the life support research program should understand and plan the R&M approach. The recent NASA technical standard on R&M has moved away from requiring specific R&M activities during each of the traditional project phases to instead developing and planning to implement the R&M requirements to meet the top level project R&M objectives. The emphasis is on providing the evidence to show that the R&M requirements are met, rather than on conducting specific prescribed R&M activities. The technical standard on R&M defines a comprehensive hierarchy of specific R&M objectives and identifies particular strategies to implement them at each level. That is, the top level R&M objective is defined and then one or more design strategies to implement it are developed immediately, before the next lower objectives are defined and the strategies to achieve those are designed. This step-by-step, top-down approach is similar to the axiomatic design method. The objectives are the R&M requirements, and the strategies are the hardware designs or operations plans developed to meet these requirements. The new R&M process is aligned with the systems design process and helps ensure that the methods to meet the R&M requirements are built into the design.

Jones, Harry W.↗
NASA NTRS2006

NASA Langley Systems Analysis & Concepts Directorate Technology Assessment/Portfolio Analysis

Systems analysis develops and documents candidate mission and architectures, associated system concepts, enabling capabilities and investment strategies to achieve NASA s strategic objectives. The technology assessment process connects the mission and architectures to the investment strategies. In order to successfully implement a technology assessment, there is a need to collect, manipulate, analyze, document, and disseminate technology-related information. Information must be collected and organized on the wide variety of potentially applicable technologies, including: previous research results, key technical parameters and characteristics, technology readiness levels, relationships to other technologies, costs, and potential barriers and risks. This information must be manipulated to facilitate planning and documentation. An assessment is included of the programmatic and technical risks associated with each technology task as well as potential risk mitigation plans. Risks are assessed and tracked in terms of likelihood of the risk occurring and consequences of the risk if it does occur. The risk assessments take into account cost, schedule, and technical risk dimensions. Assessment data must be simplified for presentation to decision makers. The Systems Analysis and Concepts Directorate (SACD) at NASA Langley Research Center has a wealth of experience in performing Technology Assessment and Portfolio Analysis as this has been a business line since 1978.

Cavanaugh, Stephen↗
NASA NTRS1982

Rice scene radiation research plan

Data requirements, tasks to be accomplished, and the technical approaches to be used in identifying the characteristics of rice for crop inventories are listed as well as methods for estimating crop development and assessing its conditions.

Heilman, J.↗
NASA NTRS1994

A strawman SLR program plan for the 1990s

A series of programmatic and technical goals for the satellite laser ranging (SLR) network are presented. They are: (1) standardize the performance of the global SLR network; (2) improve the geographic distribution of stations; (3) reduce costs of field operations and data processing; (4) expand the 24 hour temporal coverage to better serve the growing constellation of satellites; (5) improve absolute range accuracy to 2 mm at key stations; (6) improve satellite force, radiative propagation, and station motion models and investigate alternative geodetic analysis techniques; (7) support technical intercomparison and the Terrestrial Reference Frame through global collocations; (8) investigate potential synergisms between GPS and SLR.

Degnan, John J.↗
NASA NTRS2013

Crew Transportation Technical Management Processes

Under the guidance of processes provided by Crew Transportation Plan (CCT-PLN-1100), this document, with its sister documents, International Space Station (ISS) Crew Transportation and Services Requirements Document (CCT-REQ-1130), Crew Transportation Technical Standards and Design Evaluation Criteria (CCT-STD-1140), Crew Transportation Operations Standards (CCT STD-1150), and ISS to Commercial Orbital Transportation Services Interface Requirements Document (SSP 50808), provides the basis for a National Aeronautics and Space Administration (NASA) certification for services to the ISS for the Commercial Provider. When NASA Crew Transportation System (CTS) certification is achieved for ISS transportation, the Commercial Provider will be eligible to provide services to and from the ISS during the services phase.

Summary of the technical management process↗
NASA NTRSDate not supplied

Outcomes of a NASA Human Research Program’s (HRP) Space Radiation Element-sponsored Mini-Technical Interchange Meeting/workshop on Cardiovascular Disease Risk from Space Radiation

The NASA HRP’s Space Radiation Element funds research to characterize and mitigate adverse health outcomes from space radiation including cardiovascular risks to astronauts to enable deep space exploration and sustained human presence in space. Non-cancer effects such as damage to the cardiovascular system have been observed at clinically relevant high doses of ionizing radiation. However, an association between lower doses and risk of cardiovascular disease (CVD) remains somewhat controversial, especially in relation to the existence of low dose thresholds, radiation quality, and dose-rate effects, as well as gaps in characterizing the mechanisms and major pathways of disease. To facilitate, accelerate, and incubate new ideas to characterize and mitigate this risk, the Element is planning to organize a series of miniature technical interchange meetings (Tiny-TIMs) to provide a venue for HRP-funded investigators and thought leaders to present ongoing work and engage in open discussion on presented results, limitations of current approaches, incorporating better experimental strategies, model systems, etc. The initial Tiny-TIM held during the NASA HRP Investigators’ Workshop earlier this year – Upping the ante on characterizing and mitigating cardiovascular disease risk from space radiation exposure – aimed to stimulate discussion on the current state of scientific knowledge of CVD risk from space-like radiation exposure. The Tiny-TIM consisted of two 90-minute sessions; the first session concentrated on current knowledge of CVD risk from space radiation and the second session focused on innovative ideas, newer approaches, and techniques to accelerate research. The second session was followed by an open spirited discussion amongst peers on the current issues impeding the characterization of CVD risk from space radiation. The Element facilitated the discussion using a set of pressing open questions/gaps in knowledge that need to be addressed by the scientific community. The outcomes of the Tiny-TIM will be presented along with a plan of proposed future workshops and other initiatives of the Space Radiation Element.

Janapriya Saha↗
NASA NTRS1990

Yes, there was a moon race

Examination of newly disclosed evidence confirms that the Soviets were indeed striving to reach the moon before the U.S. in 1969. It is noted that a Soviet unmanned lunar probe crashed on the moon's surface only hours before the U.S. Apollo landing. Now confirmed openly are moon-exploration schedules that were competitive with Apollo plans, the names and histories of Soviet lunar boosters and landers, identities of the lunar cosmonauts; and even photos of manned lunar craft are available. Additional details on the troubled moon-probe program are presented: technical problems, continuous changes in goals, schedules, and planning, vehicle and personnel disasters, transfer of authority between ministries, and political power struggles in the scientific community.

Oberg, James E.↗
NASA NTRS1990

Distributed decision-making for space operations

A programmatic and technical perspective in the context of future space applications is presented, that includes some of the management challenges that arise as the decision-making process becomes increasingly more decentralized. Three challenges are discussed: (1) the degree to which the planners must communicate with each other and with those who are seeking space operations resources, (2) the collection, management, employment and dissemination of the information needed to make decisions, and (3) the challenges connected with schedule integration. The technical perspective presented leads to recommended adaptations to the normal scheduling algorithms that retain the 'degrees of freedom' in the planning result. It is shown that these adaptations are specific technical responses to the programmatic challenges discussed.

Hornstein, Rhoda Shaller↗
NASA NTRS2021

A sampling-based optimization approach to handling environmental uncertainty for a planetary lander

Planning for unknown environments presents a number of technical challenges. The planner must ensure robustness to unknown phenomena and manage unpredictable variation in execution, all while operating in a capacity that maximizes its objective. Productivity in the face of these challenges re-quires an integrated approach to planning and execution that is capable of accomplishing goals, reacting to variation, and maximizing overall utility. We examine this problem in the context of a Europa Lander concept mission. We model the problem as a hierarchical task network, framing it as a utility maximization problem constrained on a depletable energy resource. We propose an uncertainty–sensitive deterministic planning framework that utilizes periodic replanning to better handle model uncertainty and variable execution. We demonstrate the efficacy of our framework through simulations of a Europa Lander concept mission in which our algorithm out-performs several baseline approaches in both utility maximization and robustness

Zilberstein, Shlomo↗
NASA NTRS2021

A Sampling-Based Optimization Approach to Handling Environmental Uncertainty for a Planetary Lander

Planning for unknown environments presents a number of technical challenges. The planner must ensure robustness to unknown phenomena and manage unpredictable variation in execution, all while operating in a capacity that maximizes its objective. Productivity in the face of these challenges re-quires an integrated approach to planning and execution that is capable of accomplishing goals, reacting to variation, and maximizing overall utility. We examine this problem in the context of a Europa Lander concept mission. We model the problem as a hierarchical task network, framing it as a utility maximization problem constrained on a depletable energy resource. We propose an uncertainty–sensitive deterministic planning framework that utilizes periodic replanning to better handle model uncertainty and variable execution. We demonstrate the efficacy of our framework through simulations of a Europa Lander concept mission in which our algorithm out-performs several baseline approaches in both utility maximization and robustness

Chien, Steve↗