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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 739 records · Page 41
All sourcesNASA NTRSDOE OSTI
NASA NTRS1999

International Ultraviolet Explorer (IUE) Battery History and Performance

The "International Ultraviolet Explorer (IUE) Battery History and Performance" report provides the information on the cell/battery design, battery performance during the thirty eight (38) solar eclipse seasons and the end-of-life test data. It is noteworthy that IUE spacecraft was an in-house project and that the batteries were designed, fabricated and tested (Qualification and Acceptance) at the Goddard Space Flight Center. A detailed information is given on the cell and battery design criteria and the designs, on the Qualification and the Acceptance tests, and on the cell life cycling tests. The environmental, thermal, and vibration tests were performed on the batteries at the battery level as well as with the interface on the spacecraft. The telemetry data were acquired, analyzed, and trended for various parameters over the mission life. Rigorous and diligent battery management programs were developed and implemented from time to time to extend the mission life over eighteen plus years. Prior to the termination of spacecraft operation, special tests were conducted to check the battery switching operation, battery residual capacity, third electrode performance and battery impedance.

Rao, Gopalskrishna M.↗
NASA NTRS1998

The Influences of Airmass Histories on Radical Species During POLARIS

The POLARIS mission focused on understanding the processes associated with the decrease of polar stratospheric ozone from spring to fall at high latitudes. This decrease is linked primarily to in situ photochemical destruction by reactive nitrogen species, NO and NO2, which also control other catalytic loss cycles. Steady state models have been used to test photochemistry and radical behavior but are not always adequate in simulating radical species observations. In some cases, air mass history can be important and trajectory models give an improved simulation of the radical species. Trajectory chemistry models, however, still consistently underestimate NO and NO2 abundances compared to measurements along the ER-2 flight track. The Goddard chemistry on trajectory model has been used to test updated rate constants for NO2 + OH, NO2 + O and OH + HNO3, key reactions that affect NO and NO2 abundances. We present comparisons between the modified Goddard chemistry on trajectory model, the JPL steady state model and observations from selected flights.

Pierson, James M.↗
NASA NTRS1999

Power to Explore: A History of the Marshall Space Flight Center, 1960-1990

This scholarly study of NASA's Marshall Space Flight Center places the institution in social, political, scientific and technological context. It traces the evolution of Marshall, located in Huntsville, Alabama, from its origins as an Army missile development organization to its status in 1990 as one of the most diversified of NASA's field Center. Chapters discuss military rocketry programs in Germany and the United States, Apollo-Saturn, Skylab, Space shuttle, Spacelab, the Space Station, and various scientific and technical projects including the Hubble Space Telescope. It sheds light not only on the history of space technology, science and exploration, but also on the Cold War, federal politics and complex organizations.

Dunar, Andrew J.↗
NASA NTRS2000

Small-Scale Polygons and the History of Ground Ice on Mars

This research has laid a foundation for continued study of permafrost polygons on Mars using the models and understanding discussed here. Further study of polygonal patterns on Mars is proceeding (under new funding) which is expected to reveal more results about the origin of observed martian polygons and what information they contain regarding the recent history of tile martian climate and of water ice on Mars.

Mellon, Michael T.↗
NASA NTRS2000

The Effect of Solution Thermal History on Chicken Egg White Lysozyme Nucleation

Proteins are highly flexible molecules and often exhibit defined conformational changes in response to changes in the ambient temperature. Chicken egg white lysozyme has been previously shown to undergo an apparent structural change when warmed above the tetragonal/orthorhombic phase transition temperature. This is reflected by a change in the habit of the tetragonal and orthorhombic crystals so formed. In this study we show that possible conformational changes induced by heating are stable and apparently non- reversible by simple cooling. Exposure of protein solutions to temperatures above the phase change transition temperature, before combining with precipitant solution to begin crystallization, reduces final crystal numbers. Protein that is briefly warmed to 37 C, then cooled shows no sign of reversal to the unheated nucleation behavior even after storage for 4 weeks at 4 C. The change in nucleation behavior of tetragonal lysozyme crystals, attributed to a structural shift, occurs faster the greater the exposure to temperature above the equi-solubility point for the two phases. Heating for 2 h at 48 C reduces crystal numbers by 20 fold in comparison to the same solution heated for the same time at 30 C. Thermal treatment of solutions is therefore a possible tool to reduce crystal numbers and increase crystal size. The effects of a protein's previous thermal history are now shown to be a potentially critical factor in subsequent macromolecule crystal nucleation and growth studies.

Burke, Michael W.↗
NASA NTRS1998

Gusev Crater Paleolake: Two-Billion Years of Martian Geologic, (and Biologic?) History

Ancient Martian lakes are sites where the climatological, chemical, and possibly biological history of the planet has been recorded. Their potential to keep this global information in their sedimentary deposits, potential only shared with the polar layered-deposits, designates them as the most promising targets for the ongoing exploration of Mars in terms of science return and global knowledge about Mars evolution. Many of the science priority objectives of the Surveyor Program can be met by exploring ancient Martian lake beds. Among martian paleolakes, lakes in impact craters represent probably the most favorable sites to explore. Though highly destructive events when they occur, impacts may have provided in time a significant energy source for life, by generating heat, and at the contact of water and/or ice, deep hydrothermal systems, which are considered as favorable environments for life. In addition, impact crater lakes are changing environments, from thermally driven systems at the very first stage of their formation, to cold ice-protected potential oases in the more recent Martian geological times. Thus, they are plausible sites to study the progression of diverse microbiologic communities.

Cabrol, N. A.↗
NASA NTRS1998

Planetary Protection, Sample Return Missions and Mars Exploration: History, Status, and Future Needs

As the prospect grows for a Mars sample return mission early in the next millennium, it will be important to ensure that appropriate planetary protection (PP) controls are incorporated into the mission design and implementation from the start. The need for these PP controls is firmly based on scientific considerations and backed by a number of national and international agreements and guidelines aimed at preventing harmful cross contamination of planets and extraterrestrial bodies. The historical precedent for the use of PP measures on both unmanned and manned missions traces from post-Sputnik missions to the present, with periodic modifications as new information was obtained. In consideration of the anticipated attention to PP questions by both the scientific/technical community and the public, this paper presents a comprehensive review of the major issues and problems surrounding PP for a Mars Sample Return (MSR) mission, including an analysis of arguments that have been raised for and against the imposition of PP measures. Also discussed are the history and foundations for PP policies and requirements; important research areas needing attention prior to defining detailed PP requirements for a MSR mission; and legal and public awareness issues that must be considered with mission planning.

DeVincenzi, Donald L.↗
NASA NTRS2001

Slow Crack Growth and Fatigue Life Prediction of Ceramic Components Subjected to Variable Load History

Present capabilities of the NASA CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code include probabilistic life prediction of ceramic components subjected to fast fracture, slow crack growth (stress corrosion), and cyclic fatigue failure modes. Currently, this code has the capability to compute the time-dependent reliability of ceramic structures subjected to simple time-dependent loading. For example, in slow crack growth (SCG) type failure conditions CARES/Life can handle the cases of sustained and linearly increasing time-dependent loads, while for cyclic fatigue applications various types of repetitive constant amplitude loads can be accounted for. In real applications applied loads are rarely that simple, but rather vary with time in more complex ways such as, for example, engine start up, shut down, and dynamic and vibrational loads. In addition, when a given component is subjected to transient environmental and or thermal conditions, the material properties also vary with time. The objective of this paper is to demonstrate a methodology capable of predicting the time-dependent reliability of components subjected to transient thermomechanical loads that takes into account the change in material response with time. In this paper, the dominant delayed failure mechanism is assumed to be SCG. This capability has been added to the NASA CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code, which has also been modified to have the ability of interfacing with commercially available FEA codes executed for transient load histories. An example involving a ceramic exhaust valve subjected to combustion cycle loads is presented to demonstrate the viability of this methodology and the CARES/Life program.

Jadaan, Osama↗
NASA NTRS1998

Planetary Protection, Sample Return Missions and Mars Exploration: History, Status, and Future Needs

As the prospect grows for a Mars sample return mission early in the next millennium, it will be important to ensure that appropriate planetary protection (PP) controls are incorporated into the mission design and implementation from the start. The need for these PP controls is firmly based on scientific considerations and backed by a number of national and international agreements and guidelines aimed at preventing harmful cross contamination of planets and extraterrestrial bodies. The historical precedent for the use of PP measures on both unmanned and manned missions traces from post-Sputnik missions to the present, with periodic modifications as new information was obtained. In consideration of the anticipated attention to PP questions by both the scientific/technical community and the public, this paper presents a comprehensive review of the major issues and problems surrounding PP for a Mars Sample Return (MSR) mission, including an analysis of arguments that have been raised for and against the imposition of PP measures. Also discussed are the history and foundations for PP policies and requirements; important research areas needing attention prior to defining detailed PP requirements for a MSR mission; and legal and public awareness issues that must be considered with mission planning.

DeVincenzi, Donald L.↗
NASA NTRS2001

Continued Investigations of the Accretion History of Extraterrestrial Matter over Geologic Time

This grant supported our ongoing project to characterize the accretion rate of interplanetary dust particles (IDPs) to Earth over geologic time using He-3 as a tracer. IDPs are derived from collisions in the asteroid belt and from disaggregation of active comets. Owing to their small size (few to few hundred micrometers diameter) these particles spiral into the sun under Poynting-Robertson drag typically in less than a few tens of kyrs. Thus IDPs must be continually resupplied to the zodiacal cloud, and because the processes of IDP production are likely to be sporadic, time variation in the IDP accretion rate to Earth is likely to be time-varying. For example, major asteroidal collisions and comet showers should greatly enhance the IDP accretion rate. Our ultimate objective (still ongoing) is to document this time variance so as to better understand the history of the solar system, the source of IDPs accreting to Earth, and the details of the mechanism by which particles are captured by Earth. To document variations in IDP accretion rate through time we use He-3 as a tracer. This isotope is in extremely low abundance in terrestrial matter, but IDPs have very high concentrations of He-3 from implantation of solar wind ions. By measuring He-3 in seafloor sediments, we can estimate the IDP accretion rate for at least the last few hundred Myrs. Under an earlier NASA grant we identified the existence of a large increase in He-3 flux in the Late Eocene (35 Myr ago), coincident with the two largest impact craters of the Cenozoic Era. The simplest interpretation of this observation is the occurrence of a shower of long period comets at that time, simultaneously increasing the impact cratering probability and accretion rate of IDPs to Earth (Farley et al., 1998). Comet showers produced by stellar perturbation of the Oort cloud should be fairly common in the geologic record, so this is not an unreasonable interpretation of our observations.

Farley, Kenneth↗
NASA NTRS2001

Goals, History and Current Programs of Workshop

Mr. Robert Fusaro, coordinator for the Glenn Research Center Space Mechanisms program, presented the goals of the workshop, history of previous workshops and gave an overview of current space mechanisms work performed by Glenn Research Center. Highlights of his presentation are shown. Following the presentation, Mr. Fusaro demonstrated the new NASA Space Mechanisms Handbook and Reference Guide CD ROM, which was featured as a highlight of the workshop. The handbook is an authoritative guide for design and testing of space mechanisms and related components. Over 600 pages of guidelines written by 25 experts in the field provide in-depth information on how to design space mechanisms and components, including: deployables, release devices, latches, rotating and pointing mechanisms, dampers, motors, gears, fasteners, valves, etc. The handbook provides details on appropriate environmental and tribological testing methods and practices required to evaluate new mechanisms and components. Distribution of the Handbook and Reference Guide is limited by ITAR (International Traffic in Arms Regulations). It is available only to US companies and citizens. A request form for the CD ROM can be found on the Space Mechanisms Project website at http://www.grc.nasa.gov/WWW/spacemech/.

Source record↗
NASA NTRS1992

The Decision to Send Humans Back to the Moon and on to Mars: Space Exploration Initiative History Project

This folder contains working papers collected to date on a NASA-sponsored history project to document the events leading up to the July 20, 1989 speech setting forth the objectives of the Space Exploration Initiative. Included are a chronology of events, briefing papers produced by the NASA Working Group laying out proposal, briefing charts used to present the proposal, a copy of the President's speech, and an essay summarizing the events that led up to the announcement. Additionally, two fo the interviews conducted as part of the project are enclosed.

McCurdy, Howard E.↗