Search NASA⌕ Search

SEARCH · Search NASA

Results for “Long duration”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Long duration test of a 30-kW class thermal arcjet engine

This paper describes a recent long-duration test of a 30-kW arcjet engine. This engine performed very well for 573 hours at power levels between 24 and 29 kW and with ammonia as the propellant at a mass flow rate between 0.25 and 0.27 g/s. The specific impulse varied between about 850 and 950 s and the thrust efficiency between 36 and 40 percent. The cause of final engine failure and the conditions of the electrodes and insulator will be discussed in detail. An important part of this very long-term test effort was the performance and efficiency of the facility. The construction of this facility and the performance of the various critical components will also be discussed.

Pivirotto, T. J.↗
NASA NTRS1993

A generalized approach to the thermal analysis of the Long Duration Exposure Facility's flight experiments

The generalized method employed in the thermal analysis of a Long Duration Exposure Facility (LDEF) flight experiment is presented. The method consists of thermal math model development, defining the orbital heating rates, and applying the appropriate temperature boundary conditions. This approach has proven to be an accurate method for predicting experiment component temperatures for the worst case orbital environments and calculating daily average component temperatures for any part or all time portions of the 5.8 year mission. The application of this method to the thermal analysis of the Ultra-Heavy Cosmic-Ray Nuclei experiment (UHCRE) is presented as an example of this approach.

Sampair, Thomas R.↗
NASA NTRS2000

Systems Analysis of Life Support for Long-Duration Missions

Work defining advanced life support (ALS) technologies and evaluating their applicability to various long-duration missions has continued. Time-dependent and time-invariant costs have been estimated for a variety of life support technology options, including International Space Station (ISS) environmental control and life support systems (ECLSS) technologies and improved options under development by the ALS Project. These advanced options include physicochemical (PC) and bioregenerative (BIO) technologies, and may in the future include in-situ resource utilization (ISRU) in an attempt to reduce both logistics costs and dependence on supply from Earth. PC and bioregenerative technologies both provide possibilities for reducing mission equivalent system mass (ESM). PC technologies are most advantageous for missions of up to several years in length, while bioregenerative options are most appropriate for longer missions. ISRU can be synergistic with both PC and bioregenerative options.

IN SITU RESOURCES UTILIZATION↗
NASA NTRS2005

We Have the Spaceship; But Where's the Start Button: Human Engineering Issues in the Age of Long Duration Space Exploration - Presentation

This viewgraph presentation addresses the following considerations for human factors engineering during long duration human space flight: gravitational adaptation, 2-D to 3-D adaptation, handles, exercise posture, and space ergonomics. The presentation argues that there is an urgent need to advance research is these areas in preparation for future manned missions.

Hamilton, George↗
NASA NTRS2005

An operational approach to long-duration mission behavioral health and performance factors

NASA's participation in nearly 10 yr of long-duration mission (LDM) training and flight confirms that these missions remain a difficult challenge for astronauts and their medical care providers. The role of the astronaut's crew surgeon is to maximize the astronaut's health throughout all phases of the LDM: preflight, in flight, and postflight. In support of the crew surgeon, the NASA-Johnson Space Center Behavioral Health and Performance Group (JSC-BHPG) has focused on four key factors that can reduce the astronaut's behavioral health and performance. These factors are defined as: sleep and circadian factors; behavioral health factors; psychological adaptation factors; and human-to-system interface (the interface between the astronaut and the mission workplace) factors. Both the crew surgeon and the JSC-BHPG must earn the crewmember's trust preflight to encourage problem identification and problem solving in these four areas. Once on orbit, the crew medical officer becomes a valuable extension of the crew surgeon and BHPG on the ground due to the crew medical officer's constant interaction with crewmembers and preflight training in these four factors. However, the crew surgeon, BHPG, and the crew medical officer need tools that will help predict, prevent, monitor, and respond to developing problems. Objective data become essential when difficult mission termination decisions must be made. The need for behavioral health and performance tool development creates an environment rich for collaboration between operational healthcare providers and researchers. These tools are also a necessary step to safely complete future, more autonomous exploration-class space missions.

Review↗
NASA NTRS2008

Foot Reaction Forces during Long Duration Space Flight

Musculoskeletal changes, particularly in the lower extremities, are an established consequence of long-duration space flight despite exercise countermeasures. It is widely believed that disuse and reduction in load bearing are key to these physiological changes, but no quantitative data characterizing the on-orbit movement environments currently exist. Here we present data from the Foot Experiment (E318) regarding astronaut activity on the ground and on-orbit during typical days from 4 International Space Station (ISS) crew members who flew during increments 6, 8, 11, and 12.

Gopalakrishnan, R.↗
NASA NTRS2014

Waste Management Options for Long-Duration Space Missions: When to Reject, Reuse, or Recycle

The amount of waste generated on long-duration space missions away from Earth orbit creates the daunting challenge of how to manage the waste through reuse, rejection, or recycle. The option to merely dispose of the solid waste through an airlock to space was studied for both Earth-moon libration point missions and crewed Mars missions. Although the unique dynamic characteristics of an orbit around L2 might allow some discarded waste to intersect the lunar surface before re-impacting the spacecraft, the large amount of waste needed to be managed and potential hazards associated with volatiles recondensing on the spacecraft surfaces make this option problematic. A second option evaluated is to process the waste into useful gases to be either vented to space or used in various propulsion systems. These propellants could then be used to provide the yearly station-keeping needs at an L2 orbit, or if processed into oxygen and methane propellants, could be used to augment science exploration by enabling lunar mini landers to the far side of the moon.

Space processing↗
DOE OSTI2025

Long Duration Energy Storage Viability Survey

Energy storage technologies that can economically store and provide electricity over multi-day and seasonal timescales are likely to be a critical component of a sustainable and resilient energy system. This analysis performs a broad survey of energy storage technologies to find storage media that are promising for these long-duration energy storage applications.

levelized cost of storage↗
NASA NTRS1979

The geometry of stellar occultation measurements on long-duration atmospheric monitoring missions

Geometrical considerations are presented for analyzing use of the stellar occultation technique on long duration earth atmosphere monitoring missions. The simulated mission data are presented for three representative orbits. Bright near infrared stars are used as examples of how extensive global longitude-latitude coverage is obtained by performing occultation measurements on several stars during the course of a one year mission. A comparison is made with similar missions using the sun as a light source.

Brooks, D. R.↗
NASA NTRS1978

Radiation sensitivity of quartz crystal oscillators experiment for the Long Duration Exposure Facility /LDEF/

A proposed experiment, which has been selected by NASA for inclusion in the Long Duration Exposure Facility (LDEF), is discussed. The objective of the experiment is to obtain information relevant to predicting and improving the radiation sensitivity of quartz oscillators. Specifically, the effect of exposing various grades of quartz oscillators to an orbital environment will be compared with observations obtained using the transmission electron microscope which suggest that the technique may be used to classify quartz-crystals according to their radiation sensitivity.

Venables, J. D.↗
NASA NTRS1984

Long Duration Exposure Facility (LDEF). Mission 1 Experiments

Spaceborne experiments using the space shuttle payload known as the Long Duration Exposure Facility are described. Experiments in the fields of materials, coatings, thermal systems, power and propulsion, electronic, and optics are discussed.

Lenwood G Clark↗
NASA NTRS1993

Long Duration Exposure Facility (LDEF) attitude measurements of the Interplanetary Dust Experiment

Analysis of the data from the Long Duration Exposure Facility (LDEF) Interplanetary Dust Experiment (IDE) sun sensors has allowed a confirmation of the attitude of LDEF during its first year in orbit. Eight observations of the yaw angle at specific times were made and are tabulated in this paper. These values range from 4.3 to 12.4 deg with maximum uncertainty of plus or minus 2.0 deg and an average of 7.9 deg. No specific measurements of pitch or roll were made but the data indicates that LDEF had an average pitch down attitude of less than 0.7 deg.

Kassel, Philip C., Jr.↗
NASA NTRS2017

Gene Expression and Structural Skeletal Responses to Long-Duration Simulated Microgravity in Rats

In this study, we aim to examine skeletal responses to simulated long-duration spaceflight (90 days) and weight-bearing recovery on bone loss using the ground-based hindlimb unloading (HU) model in adolescent (3-month old) male rats. We hypothesized that simulated microgravity leads to the temporal regulation of oxidative defense genes and pro-bone resorption factors, where there is a progression and eventual plateau; furthermore, early transient changes in these pathways precede skeletal adaptations.

hindlimb unloading↗
NASA NTRS2020

Long-duration Venus lander for seismic and atmospheric science

An exciting and novel science mission concept called Seismic and Atmospheric Exploration of Venus (SAEVe) has been developed which uses high-temperature electronics to enable a three-order magnitude increase in expected surface life (120 Earth days) over what has been achieved to date. This enables study of long-term, variable phenomena such as the seismicity of Venus and near surface weather, near surface energy balance and atmospheric chemical composition. SAEVe also serves as a critical pathfinder for more sophisticated landers in the future. For example, first order seismic measurements by SAEVe will allow future missions to deliver better seismometers and systems to support the yet unknown frequency and magnitude of Venus events. SAEVe is focused on science that can be realized with low data volume instruments and will most benefit for temporal operations. The entire mission architecture and operations maximize science while minimizing energy usage and physical size and mass. The entire SAEVe system including its protective entry system is estimated to be around 45 kg and approximately 0.6 m diameter. These features allow SAEVe to be relatively cost effective and be easily integrated onto a Venus orbiter mission. The technologies needed to implement SAEVe are currently in development by several funded activities. Component and system level work is ongoing under NASA’s HOTTech program and by the Long Lived Insitu Solar System Explorer (LLISSE) project. The SAEVe long duration Venus lander promises groundbreaking science and is an ideal complimentary element to many future Venus orbiter missions being proposed or planned today.

Venus↗
DOE OSTI2024

A techno-economic survey of energy storage media for long-duration energy storage applications

Energy storage technologies that can economically store and provide electricity over multi-day and seasonal timescales are likely to be a critical component of a sustainable and resilient energy system. In this analysis, we perform a broad survey of energy storage technologies to find storage media (SM) that are promising for these long-duration energy storage (LDES) applications. The energy capital cost of the SM is identified as a key figure of merit for LDES. We develop a data collection framework to collect material price and physical property data, which are used to calculate the energy capital cost floor for 376 SM. These costs are then compared with cost targets for the LDES applications. The results show a multitude of thermal and chemical SM are economically promising, including some synthetic fuels, sensible thermal, latent thermal, thermochemical, and batteries based on low-cost materials. In contrast, currently deployed energy storage systems such as lithium-ion batteries and pumped hydro storage do not appear to be promising systems for LDES applications.

25 ENERGY STORAGE↗
NASA NTRS1992

Radiation exposure predictions for long-duration-stay Mars missions

In this study, the ionizing radiation environment is estimated, using the Mission Radiation Calculation (MIRACAL) program, for several long-duration-stay Mars missions proposed for early in the 21st century. Both long-fast and minimum energy transfer missions are evaluated, and their 30-day maximum, annual maximum, and total slab skin and blood-forming organ (BFO) doses are compared. When large flares were included while the astronauts were on the surface, the delivered dose did not significantly contribute to the total dose (less than 4 cSv BFO dose, or 8 percent of the guideline annual limit, for the most energetic event simulated) due to the substantial protection provided by the Martian atmosphere. However, dose delivered by large flares during transit is dependent on vehicle shielding and distance from the sun. All of the long-fast transfer missions studied had lower total and annual maximum doses than the corresponding minimum energy transfer missions (on average, 30 percent less for missions having no large flares and the shielding thicknesses evaluated in this study). For all the missions studied, having the astronauts spend one-third of their day during transit in a 10 g/sq cm storm shelter resulted in significantly lower total doses.

Striepe, Scott A.↗