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An availability assessment process developed by the Space Station Freedom Program Office Operations Organization is reviewed. The process under consideration is aimed at highlighting design attributes which hamper operations for development of appropriate design alternatives.
The application of optical space-to-ground links (SGLs) for high speed data distribution from geosynchronous and low earth orbiting satellites (e.g., sensor data from the planned Earth Observing System), for lunar and Mars links, and for links from interplanetary probes has been a topic of considerable recent interest. These optical SGLs could conceivably represent the system's operational baseline, or could represent backup links in the event of a GEO relay terminal failure. In this paper the availability of optical SGLs for various system/orbit configurations is considered. Single CONUS sites are assessed for their probability of cloud free line of sight (PCFLOS), and cloud free field of view (PCFFOV). PCFLOS represents an availability metric for geosynchronous platforms, while PCFFOV is a relevant performance metric for non-geostationary platforms (e.g., low earth orbiting satellites). Additionally, the availability of multiple ground terminals utilized in a diversity configuration is considered. Availability statistics vs. the number of diversity sites are derived from climatological data bases for CONUS sites.
The work performed has covered the following tasks: update commercial users requirements; assess availability of carriers and facilities; shuttle availability assessment; development of optimum accommodations plan; and payload documentation requirements assessment. The results from the first four tasks are presented. To update commercial user requirements, contacts were made with the JEA and CCDS partners to obtain copies of their most recent official flight requests. From these requests the commercial partners' short and long range plans for flight dates, flight frequency, experiment hardware and carriers was determined. A 34 by 44 inch chart was completed to give a snapshot view of the progress of commercialization in space. Further, an assessment was made of the availability of carriers and facilities. Both existing carriers and those under development were identified for use by the commercial partners. A data base was compiled to show the capabilities of the carriers. A shuttle availability assessment was performed using the primary and secondary shuttle manifests released by NASA. Analysis of the manifest produced a flight-by-flight list of flight opportunities available to commercial users. Using inputs from the first three tasks, an Optimum Accommodations Plan was developed. The Accommodation Plan shows the commercial users manifested by flight, the experiment flown, the carrier used and complete list of commercial users that could not be manifested in each calendar year.
The West TN portion of the Memphis aquifer, located within the Hatchie-Obion watershed is experiencing increased urban development, especially with the construction of "Blue Oval City", a battery manufacturing site for Ford's new electric trucks. Hayfood and Fayette counties fall within the sensitive recharge zone of the aquifer, and also contain the manufacturing megasite, making this an area of interest to highlight the consequences of increased urbanization to the aquifer. To understand the aquifers health, we averaged aquifer recharge factors seasonally to assess relationships from 2019-2022. Seasonal relationships were considered to highlight the hydrological factors that contribute to recharge, such as water balance, runoff, and evaporative stress that flux season to season (i.e. less precipitation in summer).
Airport runway grooving to improve tire traction
In this work we suggest the corrosion of polished bared metal coupons as a passive sensor to detect or identify the lower limit of water availability that could be suitable for biological activity in the Atacama Desert on soil or solid substrates. For this purpose, carbon steel coupons were deposited in selected sites along a west-east transect and removed at predetermined times for morphological inspection. The advantage of this procedure is that the attributes of the oxide layer (corrosion extent, morphology and oxide phases) can be considered as a fingerprint of the atmospheric moisture history at a given time interval. Two types of coupons were used, a long rectangular shape that are half-buried in a vertical position, and square shape that are deposited on the soil surface. The morphological attributes observed by SEM inspection is correlated to the so-called humectation time which is determined from local meteorological parameters. The main result is that the decreasing trend of atmospheric moisture along the transect is closely related to corrosion behavior and water soil penetration. For instance, while in the coastal site oxide phases formed on the coupon surface rapidly evolve to well- crystallized species, in the driest inland site Lomas Bayas only amorphous oxide is observed.
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The Memphis Aquifer (MA) is located in the Mississippi Embayment that extends 250,000 square kilometers across eight states. Fayette and Haywood counties in West Tennessee are situated within the recharge zone of the MA and include the forthcoming Ford “mega campus” named Blue Oval City (BOC), which will consist of a vehicle-production facility and battery assembly division. Increased water demand and land cover change resulting from urban development, such as BOC in the MA’s narrow recharge zone, threaten the aquifer’s groundwater storage and recharge rate. Groundwater recharge factors that influence the narrow recharge zone of the MA include precipitation, evapotranspiration, runoff, and land cover type. In partnership with Protect Our Aquifer (POA) and the Center for Applied Earth Science and Engineering Research (CAESAR) at the University of Memphis, the team used data from the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS), Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (GPM IMERG), and Landsat 8 Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS). The team also used ancillary data from the National Land Cover Database (NLCD) and the North American Land Data Assimilation System (NLDAS) Noah Land Surface Model. These results identified “thriving” recharge locations, which are areas most conducive to aquifer recharge in Fayette County. The partners may use the results to prioritize specific areas in need of protection before they become susceptible to the effects of urbanization and industrialization.
The Memphis aquifer is an indispensable source of water for municipal, agricultural, and industrial use across west Tennessee. The aquifer's water is thousands of years old and in pristine condition due to the natural geological filtering by the aquifer’s confining clay layers. To sustain the aquifer’s water supply, recharge must happen at a rate efficient enough to keep up with pumping from the aquifer. In partnership with Protect Our Aquifer and the University of Memphis Center for Applied Earth Science and Engineering Research, this project examined multiple factors to discover thriving areas of recharge in west Tennessee. The team used Integrated Multi-satellite Retrievals for GPM (IMERG) precipitation data, ECOsystem Spaceborne Thermal Radiometer on Space Station (ECOSTRESS) evapotranspiration data, Landsat 8 and National Land Cover Database (NLCD) to track landcover change, and the North American Land Data Assimilation System (NLDAS) Noah land surface model to estimate monthly runoff. These factors were averaged seasonally from 2019 to 2022 to understand seasonal relationships within the study area. Precipitation and evapotranspiration data were used to create water balance maps and with the evaporative stress index (ESI), landcover, and runoff maps, the team pinpointed locations that are most conducive to recharge. The team determined that areas where the water balance is low, ESI is high, and where there is sufficient pervious landcover are locations where recharge happens most effectively. Identification of effective recharge locations may be used by the partners to prioritize areas in need of protection before they become impacted by industrialization and urbanization.
A preliminary reliability, availability, and maintainability (RAM) analysis of the proposed Space Station Freedom electric power system (EPS) was performed using the unit reliability, availability, and maintainability (UNIRAM) analysis methodology. Orbital replacement units (ORUs) having the most significant impact on EPS availability measures were identified. Also, the sensitivity of the EPS to variations in ORU RAM data was evaluated for each ORU. Estimates were made of average EPS power output levels and availability of power to the core area of the space station. The results of assessments of the availability of EPS power and power to load distribution points in the space stations are given. Some highlights of continuing studies being performed to understand EPS availability considerations are presented.
In an on-going effort to make human Mars missions more affordable and sustainable, NASA continues to investigate the innovative leveraging of technological advances in conjunction with the use of accessible Martian resources directly applicable to these missions. One of the resources with the broadest utility for human missions is water. Many past studies of human Mars missions assumed a complete lack of water derivable from local sources. However, recent advances in our understanding of the Martian environment provides growing evidence that Mars may be more "water rich" than previously suspected. This is based on data indicating that substantial quantities of water are mixed with surface regolith, bound in minerals located at or near the surface, and buried in large glacier-like forms. This paper describes an assessment of what could be done in a "water rich" human Mars mission scenario. A description of what is meant by "water rich" in this context is provided, including a quantification of the water that would be used by crews in this scenario. The different types of potential feedstock that could be used to generate these quantities of water are described, drawing on the most recently available assessments of data being returned from Mars. This paper specifically focuses on sources that appear to be buried quantities of water ice. (An assessment of other potential feedstock materials is documented in another paper.) Technologies and processes currently used in terrestrial polar regions is reviewed. One process with a long history of use on Earth and with potential application on Mars - the Rodriguez Well - is described and results of an analysis simulating the performance of such a well on Mars are presented. These results indicate that a Rodriguez Well capable of producing the quantities of water identified for a "water rich" human mission are within the capabilities assumed to be available on the Martian surface, as envisioned in other comparable Evolvable Mars Campaign assessments. The paper concludes by capturing additional findings and describing additional simulations and tests that should be conducted to better characterize the performance of the identified terrestrial technologies for accessing subsurface ice, as well as the Rodriguez Well, under Mars environmental conditions.
In an on-going effort to make human Mars missions more affordable and sustainable, NASA continues to investigate the innovative leveraging of technological advances in conjunction with the use of accessible Martian resources directly applicable to these missions. One of the resources with the broadest utility for human missions is water. Many past studies of human Mars missions assumed a complete lack of water derivable from local sources. However, recent advances in our understanding of the Martian environment provides growing evidence that Mars may be more "water rich" than previously suspected. This is based on data indicating that substantial quantities of water are mixed with surface regolith, bound in minerals located at or near the surface, and buried in large glacier-like forms. This paper describes an assessment of what could be done in a "water rich" human Mars mission scenario. A description of what is meant by "water rich" in this context is provided, including a quantification of the water that would be used by crews in this scenario. The different types of potential feedstock that could be used to generate these quantities of water are described, drawing on the most recently available assessments of data being returned from Mars. This paper specifically focuses on sources that appear to be buried quantities of water ice. (An assessment of other potential feedstock materials is documented in another paper.) Technologies and processes currently used in terrestrial Polar Regions are reviewed. One process with a long history of use on Earth and with potential application on Mars - the Rodriguez Well - is described and results of an analysis simulating the performance of such a well on Mars are presented. These results indicate that a Rodriguez Well capable of producing the quantities of water identified for a "water rich" human mission are within the capabilities assumed to be available on the Martian surface, as envisioned in other comparable Evolvable Mars Campaign assessments. The paper concludes by capturing additional findings and describing additional simulations and tests that should be conducted to better characterize the performance of the identified terrestrial technologies for accessing subsurface ice, as well as the Rodriguez Well, under Mars environmental conditions.
Under-utilized forest resources in the Northeast can supply fiber to new markets. Information on forest resources, however, is often too aggregated to estimate available woody material with sufficient detail for planning specific projects. Over the past year, staff of Cornell University's Remote Sensing Program, under a grant from NASA, assisted New York State agency personnel by assessing available woody material for two potential development projects, a wood-fired power plant and a particle board manufacturing plant. These feasibility studies are reviewed, illustrating how information derived from high-altitude aircraft photographs, LANDSAT imagery, and available supporting data were integrated to arrive at estimates of woody material.
Exploration class missions will be required to have an exercise device that is lightweight, has a small footprint, and is capable of providing enough physical stimulus and exercise variability to be an effective countermeasure against muscle, bone, aerobic fitness, and sensorimotor loss that results from the microgravity environment. Ground studies, inflight studies, and results analyses are required to inform Moon2Mars Design Reference Missions (DRMs) and vehicle designs. This activity encompasses two related projects, an evaluation study called Zero T2 and a requirements development for an exploration treadmill (ET). Exploration class missions’ mass/power/volume restrictions have resulted in the development of exercise devices that are motorized and flywheel-based to provide both aerobic and resistive training on one platform. These devices provide a variety of full body resistance exercise options as well as rowing and cycling for aerobic exercise, but do not provide ambulatory exercise via a treadmill. Because a treadmill has been available for use on the ISS since 2001, we do not understand the efficacy of exploration exercise modalities on muscle performance, aerobic fitness, bone health, or sensorimotor performance. A retrospective study was performed to quantify the association between total exercise (including specific contributions of treadmill exercise) and functional performance upon landing. Due to the relatively small variation in treadmill usage inflight, there is a need to do a controlled study where inflight crewmembers will not use the ISS treadmill (called T2) for the duration of their flights. There will be 3 arms to the Zero T2 study: 1) participants use all currently available exercise platforms aboard ISS (control group), 2) participants use only ARED and CEVIS, and 3) participants use only European Enhanced Exploration Device (E4D). (Please see the TechPort Entry for Exploration Exercise System Development for further detail on the E4D.) This study started in Oct 2020 and will continue through Sep 2027. In a parallel effort, a team will be developing requirements for an exploration treadmill. This project will be broken into two phases. Phase 1 will develop and implement energy prediction models based on available in-flight exercise data to quantify energy expenditure during 0g treadmill running. Phase 2 will then use the available biomechanical and metabolic evidence from Phase 1 to determine the hardware specification requirements essential to providing the desired exercise stimulus. Subject Matter Experts (SMEs) will then leverage the Standardized Process for Evaluating Exercise Devices (SPEED) developed by the team to 1) assess available technologies for candidate treadmills which meet defined requirements, 2) perform hands-on evaluations of top candidates, 3) provide evaluation outcomes and recommendations to developers. This project will begin in 2025 and continue through Sep 2030.
The ISS provides an excellent opportunity for pioneering artificial intelligence software to meet the challenges of real-time communications (comm) link management. This opportunity empowers the ISS Program to forge a testbed for developing cognitive communications systems for the benefit of the ISS mission, manned Low Earth Orbit (LEO) science programs and future planetary exploration programs. In November, 1998, the Flight Operations Directorate (FOD) started the ISS Antenna Manager (IAM) project to develop a single processor supporting multiple comm satellite tracking for two different antenna systems. Further, the processor was developed to be highly adaptable as it supported the ISS mission through all assembly stages. The ISS mission mandated communications specialists with complete knowledge of when the ISS was about to lose or gain comm link service. The current specialty mandated cognizance of large sun-tracking solar arrays and thermal management panels in addition to the highly-dynamic satellite service schedules and rise/set tables. This mission requirement makes the ISS the ideal communications management analogue for future LEO space station and long-duration planetary exploration missions. Future missions, with their precision-pointed, dynamic, laser-based comm links, require complete autonomy for managing high-data rate communications systems. Development of cognitive communications management systems that permit any crew member or payload science specialist, regardless of experience level, to control communications is one of the greater benefits the ISS can offer new space exploration programs. The IAM project met a new mission requirement never previously levied against US space-born communications systems management: process and display the orientation of large solar arrays and thermal control panels based on real-time joint angle telemetry. However, IAM leaves the actual communications availability assessment to human judgment, which introduces unwanted variability because each specialist has a different core of experience with comm link performance. Because the ISS utilizes two different frequency bands, dynamic structure can be occasionally translucent at one frequency while it can completely interdict service at the other frequency. The impact of articulating structure on the comm link can depend on its orientation at the time it impinges on the link. It can become easy for a human specialist to cross-associate experience at one frequency with experience at the other frequency. Additionally, the specialist's experience is incremental, occurring one nine-hour shift at a time. Only the IAM processor experiences the complete 24x7x365 communications link performance for both communications links but, it has no "learning capability." If the IAM processor could be endowed with a cognitive ability to remember past structure-induced comm link outages, based on its knowledge of the ISS position, attitude, communications gear, array joint angles and tracking accuracy, it could convey such experience to the human operator. It could also use its learned communications link behaviors to accurately convey the availability of future communications sessions. Further, the tool could remember how accurately or inaccurately it predicted availability and correct future predictions based on past performance. The IAM tool could learn frequency-specific impacts due to spacecraft structures and pass that information along as "experience." Such development would provide a single artificial intelligence processor that could provide two different experience bases. If it also "knew" the satellite service schedule, it could distinguish structure blockage from schedule or planet blockage and then quickly switch to another satellite. Alternatively, just as a human operator could judge, a cognizant comm system based on the IAM model could "know" that the blockage is not going to last very long and continue tracking a comm satellite, waiting for it to track away from structure. Ultimately, once this capability was fully developed and tested in the Mission Control Center, it could be transferred on-orbit to support development of operations concepts that include more advanced cognitive communications systems. Future applications of this capability are easily foreseen because even more dynamic satellite constellations with more nodes and greater capability are coming. Currently, the ISS fully employs a 300 million bit-per-second (Mbps) return link for harvesting payload science. In the coming eighteen months, it will step up to 600 Mbps. Already there is talk of a 1.2 billion bit-per-second (Gbps) upgrade for the ISS and laser comm links have already been tested from the ISS. Every data rate upgrade mandates more complicated and sensitive communications equipment which implies greater expertise invested in the human operator. Future on-orbit cognizant comm systems will be needed to meet greater performance demands aboard larger, far more complicated spacecraft. In the LEO environment, the old-style one-satellite-per-spacecraft operations concept will give way to a new concept of a single customer spacecraft simultaneously using multiple comm satellites. Much more highly-dynamic manned LEO missions with decades of crew members potentially increase the demand for communications link performance. A cognizant on-board communications system will meet advanced communications demands from future LEO missions and future planetary missions. The ISS has fledgling components of future exploration programs, both LEO and planetary. Further, the Flight Operations Directorate, through the IAM project, has already begun to develop a communications management system that attempts to solve advanced problems ideally represented by dynamic structure impacting scheduled satellite service. With an earnest project to integrate artificial intelligence into the IAM processor, the ISS Program could develop a cognizant communications system that could be adapted and transferred to future on-orbit avionics designs.
The ISS provides an excellent opportunity for pioneering artificial intelligence software to meet the challenges of real-time communications (comm) link management. This opportunity empowers the ISS Program to forge a testbed for developing cognitive communications systems for the benefit of the ISS mission, manned Low Earth Orbit (LEO) science programs and future planetary exploration programs. In November, 1998, the Flight Operations Directorate (FOD) started the ISS Antenna Manager (IAM) project to develop a single processor supporting multiple comm satellite tracking for two different antenna systems. Further, the processor was developed to be highly adaptable as it supported the ISS mission through all assembly stages. The ISS mission mandated communications specialists with complete knowledge of when the ISS was about to lose or gain comm link service. The current specialty mandated cognizance of large sun-tracking solar arrays and thermal management panels in addition to the highly-dynamic satellite service schedules and rise/set tables. This mission requirement makes the ISS the ideal communications management analogue for future LEO space station and long-duration planetary exploration missions. Future missions, with their precision-pointed, dynamic, laser-based comm links, require complete autonomy for managing high-data rate communications systems. Development of cognitive communications management systems that permit any crew member or payload science specialist, regardless of experience level, to control communications is one of the greater benefits the ISS can offer new space exploration programs. The IAM project met a new mission requirement never previously levied against US space-born communications systems management: process and display the orientation of large solar arrays and thermal control panels based on real-time joint angle telemetry. However, IAM leaves the actual communications availability assessment to human judgement, which introduces unwanted variability because each specialist has a different core of experience with comm link performance. Because the ISS utilizes two different frequency bands, dynamic structure can be occasionally translucent at one frequency while it can completely interdict service at the other frequency. The impact of articulating structure on the comm link can depend on its orientation at the time it impinges on the link. It can become easy for a human specialist to cross-associate experience at one frequency with experience at the other frequency. Additionally, the specialist's experience is incremental, occurring one nine-hour shift at a time. Only the IAM processor experiences the complete 24x7x365 communications link performance for both communications links but, it has no "learning capability." If the IAM processor could be endowed with a cognitive ability to remember past structure-induced comm link outages, based on its knowledge of the ISS position, attitude, communications gear, array joint angles and tracking accuracy, it could convey such experience to the human operator. It could also use its learned communications link behaviors to accurately convey the availability of future communications sessions. Further, the tool could remember how accurately or inaccurately it predicted availability and correct future predictions based on past performance. The IAM tool could learn frequency-specific impacts due to spacecraft structures and pass that information along as "experience." Such development would provide a single artificial intelligence processor that could provide two different experience bases. If it also "knew" the satellite service schedule, it could distinguish structure blockage from schedule or planet blockage and then quickly switch to another satellite. Alternatively, just as a human operator could judge, a cognizant comm system based on the IAM model could "know" that the blockage is not going to last very long and continue tracking a comm satellite, waiting for it to track away from structure. Ultimately, once this capability was fully developed and tested in the Mission Control Center, it could be transferred on-orbit to support development of operations concepts that include more advanced cognitive communications systems. Future applications of this capability are easily foreseen because even more dynamic satellite constellations with more nodes and greater capability are coming. Currently, the ISS fully employs its high-data-rate return link for harvesting payload science. In the coming months, it will double that data rate and is forecast to fully utilize that capability. Already there is talk of an upgrade that quadruples the current data rate allocated to ISS payload science before the end of its mission and laser comm links have already been tested from the ISS. Every data rate upgrade mandates more complicated and sensitive communications equipment which implies greater expertise invested in the human operator. Future on-orbit cognizant comm systems will be needed to meet greater performance demands aboard larger, far more complicated spacecraft. In the LEO environment, the old-style one-satellite-per-spacecraft operations concept will give way to a new concept of a single customer spacecraft simultaneously using multiple comm satellites. Much more highly-dynamic manned LEO missions with decades of crew members potentially increase the demand for communications link performance. A cognizant on-board communications system will meet advanced communications demands from future LEO missions and future planetary missions. The ISS has fledgling components of future exploration programs, both LEO and planetary. Further, the Flight Operations Directorate, through the IAM project, has already begun to develop a communications management system that attempts to solve advanced problems ideally represented by dynamic structure impacting scheduled satellite service. With an earnest project to integrate artificial intelligence into the IAM processor, the ISS Program could develop a cognizant communications system that could be adapted and transferred to future on-orbit avionics designs.
The results of an analysis of wind-tunnel data for the effect of wave shape on local boundary layer flows and heat transfer are used to assess the feasibility of using corrugated panels on a Single-Stage-To-Orbit (SSTO) vehicle. In the flight assessment, available engineering design procedures are used to compute the inviscid and boundary layer flow for a given flight trajectory. The flight vehicle flow field calculations are then used in conjunction with wind-tunnel corrugated panel heating data correlations to examine the heating penalties associated with using corrugated panels at a number of locations on the vehicle. Severe heating penalties, as a result of the corrugations, were found over large areas of the windward surface. Maximum surface temperature penalties ranged from 100K to 500K and very large structural advantages for the corrugations would be required to override the heating penalties. Computed peak corrugation temperatures were within allowable limits of the equivalent smooth wall material for most leeward and side fuselage locations and corrugated panels will be most likely limited to these locations.
The extent of the threat to the US helicopter industry posed by a determined effort by foreign manufacturers, European companies in particular, to supply their own domestic markets and also to penetrate export markets, including the USA is assessed. Available data on US and world markets for civil and military uses are collated and presented in both graphic and tabular form showing the past history of production and markets and, where forecasts are available, anticipated future trends. The data are discussed on an item-by-item basis and inferences are drawn in as much depth as appears justified.