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NASA NTRSDate not supplied

The Effects of Plasma Application on Radish Seeds with Implications for Space Crop Production

In extended space missions, the astronaut diet will consist mostly of prepackaged foods. This could result in nutritional deficiencies due to the gradual breakdown of certain vitamins. To address this deficiency, fresh produce must be grown from seed during spaceflight. Stored seeds, however, can be vulnerable to microbial contamination which could jeopardize plant health and crop food safety. To alleviate this concern, the current practice is to sanitize seeds on the ground before spaceflight to the International Space Station (ISS). Methods of seed sanitization include alcohol soaking and chlorine gas fumigation, which have harmful effects on the environment and human health. Plasma application is a new sanitization approach that avoids these negative side effects while potentially elevating germination rate and improving growth rate; yet plasma application requires specific exposure time, power, and pressure to achieve these benefits. In the present study, Raphanus sativus ‘Cherry Belle’ radish seeds were exposed to either low pressure (Diener) plasma or atmospheric pressure plasma for varying increments of time (30s-1200s). Data collected includes immediate germination rate (viability) and microbial log reduction. Additionally, seeds were stored for later germination rate testing. Microbial assay controls have highlighted variability in initial microbial load between individual seeds, and further work is being performed to determine the standard microbial load of an untreated seed. In some samples, a negative log reduction was observed after plasma treatment encouraging further study to determine if the plasma is perforating the seed coat and releasing endophytic microbes. Treatment with Diener plasma shows promising microbial log reduction, but lower viability. In contrast, treatment with atmospheric pressure plasma offers high viability, but poor microbial log reduction. Further study will aim at determining whether plasma treatment is effective at not only sanitization, but sterilization. This research was funded by a NASA grant at the Kennedy Space Center.

Space Crop Production↗

NASA NTRS2025

Measuring Unique Contextual Factors: Group Living Skills

BACKGROUND The Human Factors and Behavioral Performance Exploration Measures (HFBP-EM) suite is a set of standardized measures used to assess behavioral health and performance risks related to future exploration-class space missions. During the HFBP-EM suite development, the importance of assessing unique contextual factors to understand the drivers of team dynamics was identified. Group living skills are a unique workplace skill which applies to those coworkers who live and work together. As mission lengths become longer, the line between work and non-work life may blur. Extreme living conditions such as spaceflight can result in increased stress over time, negatively impact mood and well-being, decrease team cohesion and increase conflict, deteriorate task performance, and potentially reduce mission success [1]. With no breaks in their isolated and confined environment possible, living with a messy, inconsiderate crewmember can add to the stress. Alternatively, crews with good group living skills may support one another, mitigating the negative effects of the extreme environment. There was no direct measure of group living skills. This work sought to fill this measurement gap and collect data related to group living in isolated, confined, extreme (ICE) environments. METHODS Group living skills as an astronaut competency area were developed with the input of experts familiar with ICE environments. Distinct aspects of this competency were reviewed and discussed by a NASA-invited group of spaceflight experts in 2015 to identify individual and team behavioral health and performance measures for operational environments. This work resulted in a 5-item measure focused on group living experiences with each crewmember (or the crew as a whole). A 6th item asks whether an individual would go on another mission with a particular crewmember or crew as a measure of future-oriented group living, or team viability. The measure was deployed in 24 teams living and working together in isolated and confined environments (e.g., International Space Station, space mission simulation analogs). RESULTS & DISCUSSION In this presentation, we will summarize results which indicate the Group Living Skills (GLS) Survey is a reliable, valid, and operationally feasible measure. Reliability was evaluated in several ways. Two-way multilevel mixed models revealed strong repeated measures reliability (ICC2 = .902, Omega between = .954). Reliability of change within teams was strong (Rc = .81). Factor analysis showed a consistent two-factor structure when individuals rated either the whole crew, all individuals, just peers, or a focal roommate. The latter used a sociometric approach to rating the GLS of the roommates. The two factors were tidiness and being considerate of others. We assessed the criterion-related validity of GLS, by examining GLS operationalized as the team-level aggregated GLS Survey scores as a predictor of team viability, team cohesion, and team performance. We used generalized mixed models to account for the repeated measures and longitudinal data. The marginal R2 change was used to determine the extent to which GLS were related to the team outcomes while controlling for mission day and campaign. Results suggested GLS was strongly related to team viability (marginal R2 change = .40), team cohesion (marginal R2 change = 0.28), social cohesion (marginal R2 change = 0.25), and moderately related to task cohesion (marginal R2 change = 0.18). GLS scores had a small relationship with team performance (marginal R2 change = .08). Results support GLS as a measure that can be used to capture group living skills of crews who live and work together in ICE. Because the items were written to be broadly applicable, less extreme environments with teams living and working together for some length of time also benefit from this measure (e.g., college roommates, camps). See Landon et al. (2024) for full results [2]. SUMMARY We report reliability and validity evidence for a new measure that assesses the Group Living Skills for teams that live and work in operational environments such as spaceflight.

J C W Miller↗

NASA NTRS1972

A look at V/STOL for business aircraft.

Attempt to ascertain the economic viability of the V/STOL capability for business aircraft and the manner in which this viability depends on the aircraft concept. A cost-benefit analysis is presented which indicates that a VTOL business aircraft would be more viable economically than a contemporary turbine-powered business aircraft. The combination of traveler's time value and trip distance for which each aircraft dominates is shown. The significance of disk loading in V/STOL concept application is discussed, and preliminary design configuration studies for three different business-aircraft-sized V/STOLs, using three concepts covering a range of disk loading, are presented as examples. Finally, a discussion of operational aspects of interest to future users of V/STOL business aircraft is presented which centers around the requirements for routine IFR terminal-area operations.

Feistel, T. W.↗

NASA NTRS1973

Infectivity and egg production of Nematospiroides dubius as affected by space flight and ultraviolet irradiation

Nematospiroides dubius was tested to determine the infective potential of the third stage larvae and the egg-production and egg-viability rates of the resulting adults after they are exposed to space flight and solar ultraviolet irradiation. The results are indicative that space-flown larvae exposed to solar ultraviolet irradiation were rendered noninfective in C57 mice, whereas flight control larvae that received no solar ultraviolet irradiation matured at the same rate as the ground control larvae. However, depressed egg viability was evident in the flight control larvae.

Long, R. A.↗

NASA NTRS1973

Quiet turbofan STOL aircraft for short haul transportation, volume 1

The characteristics for a quiet turbofan short takeoff aircraft for short haul transportation applications are discussed. The following subjects are examined: (1) representative aircraft configurations, characteristics, and costs associated with the short haul aircraft development and operation, (2) critical technology and technology related problems to be resolved in successful introduction of representative short haul aircraft, (3) relationships between quiet short takeoff aircraft and the economic and social viability of short haul, and (4) identification of high payoff technology areas. In order to properly evaluate the candidate aircraft designs and to determine their economic viability and community acceptance, a real world scenario was developed and projected to 1990.

Renshaw, J. H.↗

NASA NTRS1973

Study of quiet turbofan STOL aircraft for short-haul transportation. Volume 5: Economics

The economic aspects of the STOL aircraft for short-haul air transportation are discussed. The study emphasized the potential market, the preferred operational concepts, the design characteristics, and the economic viability. Three central issues governing economic viability are as follows: (1) operator economics given the market, (2) the required transportation facilities, and (3) the external economic effects of a set of regional STOL transportation systems.

Source record↗

NASA NTRS1979

Preparation of guinea pig macrophage for electrophoretic experiments in space

Methods of storage and cultivation of macrophage cells in preparation for space experiments were investigated. Results show that freezing and thawing immediately after extraction did not cause any change in viability or electrophoretic mobility of the cells. A prolonged storage at -80 C did cause cell damage as indicated by a 95% reduction in variable cells. Cell damage was decreased when Glycerol or Dimethyl Sulfoxide (DMSO) was added as a cryogenic protective agent. A 100% viability was observed in cultivation experiments after two weeks due to the additional serum. Results from gamma-glutamyl transpeptidase study showed a zero activity rate. It is suggested that a flat stationary field be used for the collection and use of macrophage. It was found that a 24-hour delay in obtaining macrophage cells helps to maintain a pure culture.

Source record↗

NASA NTRS1985

Evaluation of results of cell electrophoresis experiments on space shuttle STS-3 including pre-flight and post-flight laboratory experiments

The objectives of the red blood cell experiments were to provide a visual check on the electrophoretic process and especially electroosmotic flow in space as well as to provide test separations of non-degradable standard particles for comparison with the separations of the three viable cell types studied on the Apollo-Soyuz Test Project. Determination of the maximum concentrations of cells that can be separated in column electrophore was a significant goal. Two of the eight columns were available for red cell experiments, so two concentrations of human and rabbit RBC mixtures were used. The objectives of another experiment were to evaluate the reproducibility of microgravity electrophoretic separation of living kidney cells, to separate cells with highly viability despite two freeze-thaw cycles, and to optimize the physical conditions of cell separation. Owing to the uncertain heterogeneity of the starting material, the experimental design does not assess resolution in microgravity, but improved separability was sought in comparison to density-gradient electrophoresis or continuous-flow electrophoresis. Efforts were made to increase cell yield and cell viability and to assess reproducibility directly.

Todd, P. W.↗

NASA NTRS1985

Pre-flight report on cultured human embryonic kidney cell handling and cell electrophoresis. Prepared prior to continuous-flow electrophoretic separation experiments aboard space shuttle flight STS-8

Studies of the physical properties of continuous-flow zero-G electrophoretic separator (CFES) buffer, the electrokinetic properties of human erythrocytes in the CFES buffer, the electrokinetic properties of human embryonic kidney cells in the CFES buffer, and the viability and yield of human embryonc kidney cells subjected to flight handling procedures are discussed. In general, the procedure for cell handling and electrophoresis of HEK-8514 cells in 1st or 2nd passage on STS-8 is acceptable if executed properly. The CFES buffer has ionic strength that is barely compatible with cell viability and membrane stability, as seen in experiments with human erythrocytes and trypan-blue staining of human kidney cells. Cells suspended in 10% dialysed horse serum for 3 days in the cold appear to be more stable than freshly trypsinized cells. 10% horse serum appears to be superior to 5% horse serum for this purpose. The mean absolute raw mobility of HEK-8514 cells in CFES buffer at 6 degrees, conductivity 0.055 mmho/cm, is 1.1 to 1.4 um-cm/V-sec, with a range of nearly a whole mobility unit.

Todd, P. W.↗

NASA NTRS1985

Power conditioning subsystems for photovoltaic central-station power plants - Technology and performance

Central-Station (CS) Photovoltaic (PV) systems have the potential of economically displacing significant amounts of centrally generated electricity. However, the technical viability and, to some extent, the economic viability of central-station PV generation technology will depend upon the availability of large power conditioners that are efficient, safe, reliable, and economical. This paper is an overview of the technical and cost requirements that must be met to develop economically viable power conditioning subsystems (PCS) for central-station power plants. The paper also examines various already commercially available PCS hardware that may be suitable for use in today's central PV power stations.

Krauthamer, S.↗

NASA NTRS1989

Increased efficiency of mammalian somatic cell hybrid production under microgravity conditions during ballistic rocket flight

The electrofusion of hybridoma cell lines under short-duration microgravity during a flight of the TEXUS 18 Black Brand ballistic sounding rocket at Kiruna, Sweden is reported. The fusion partners, growth medium, cell fusion medium, cell fusion, cell viability in the fusion medium, and postfusion cell culture are described, and the rocket, cell fusion chamber, apparatus, and module are examined. The experimental timeline, the effects of fusion medium and incubation time on cell viability and hybrid yields, and the effect of microgravity on hybrid yields are considered.

Schnettler, R.↗

NASA NTRS1992

A conceptual design of a large aperture microwave radiometer geostationary platform

A conceptual design of a Large Aperture Microwave Radiometer (LAMR) Platform has been developed and technology areas essential to the design and on-orbit viability of the platform have been defined. Those technologies that must be developed to the requirement stated here for the LAMR mission to be viable include: advanced radiation resistant solar cells, integrated complex structures, large segmented reflector panels, sub 3 kg/m(exp 2) areal density large antennas, and electric propulsion systems. Technology areas that require further development to enhance the capabilities of the LAMR platform (but are not essential for viability) include: electrical power storage, on-orbit assembly, and on-orbit systems checkout and correction.

Garn, Paul A.↗

NASA NTRS1992

Economic benefits of supersonic overland operation

Environmental concerns are likely to impose some restrictions on the next generation of supersonic commercial transport. There is a global concern over the effects of engine emissions on the ozone layer which protects life on Earth from ultraviolet radiation. There is also some concern over community noise. The High Speed Civil Transport (HSCT) must meet at least the current subsonic noise certification standards to be compatible with the future subsonic fleet. Concerns over sonic boom represent another environmental and marketing challenge to the HSCT program. The most attractive feature of the supersonic transport is speed, which offers the traveling public significant time-savings on long range routes. The sonic boom issue represents a major environmental and economic challenge as well. Supersonic operation overland produces the most desirable economic results. However, unacceptable overland sonic boom raise levels may force HSCT to use subsonic speeds overland. These environmental and economic challenges are likely to impose some restrictions on supersonic operation, thus introducing major changes to existing route structures and future supersonic network composition. The current subsonic route structure may have to be altered for supersonic transports to avoid sensitive areas in the stratosphere or to minimize overland flight tracks. It is important to examine the alternative route structure and the impact of these restrictions on the economic viability of the overall supersonic operation. Future market potential for HSCT fleets must be large enough to enable engine and airframe manufacturers to build the plane at a cost that provides them with an attractive return on investment and to sell it at a price that allows the airlines to operate with a reasonable margin of profit. Subsonic overland operation of a supersonic aircraft hinders its economic viability. Ways to increase the market potential of supersonic operation are described.

Metwally, Munir↗

NASA NTRS1995

Radiobiological experiments with plant seeds aboard the biosatellite Cosmos 1887

The effects of spaceflight factors on the seeds of Arabidopsis thaliana and Crepis capillaris were studied. The seeds were located inside the satellite in an open space, protected with aluminum foil and also exposed without the foil cover. When the seeds were in open space without any protection, their viability was found to be suppressed; the survival rate and fertility of plants grown from these seeds were also diminished. An increase in the frequency of chromosome aberrations (CA) and in the number of multiple injuries was registered in this case. Experiments with the aluminum foil shielding showed a decrease in the suppression of the seeds' viability, but mutational changes were found to be even more increased, while the survival rate and fertility of the plants decreased. An increase in the thickness of shielding resulted in a decrease in the effects up to the level of the control, except for the effects connected with CA and fertility of the plants. Analysis of the results shows that these impairments can be ascribed to the action of single heavy charged particles (HCP). The seeds can thus be regarded as an integral biological 'dosimeter' which allows estimation of the total effects of radiation, ecological and biological factors.

Benton, E. V.↗

NASA NTRS1993

The high speed civil transport: A technology challenge

It has been over 17 years since Concorde entered service with British Airways and Air France. The thirteen production aircraft are still safely operating and may extend their service life into the next century. We can appreciate the technical success Concorde has achieved. However, from the onset the aircraft was unable to achieve overall economic viability. Currently the aircraft does generate a yearly profit for British Airways which is privatized. Unacceptable airport noise and sonic boom overland levels were detrimental to the aircraft performing between many worldwide city pairs. On the horizon appears a possible successor to Concorde that will need to demonstrate environmental acceptability and economic viability shortly after the turn of the century. This vehicle has been labelled the High Speed Civil Transport (HSCT). I believe that we can overcome the environmental and economic goals based on encouraging market demand forecasts and technology improvements that are materializing in current research and development programs.

Mortlock, Alan K.↗

NASA NTRS1996

The Attributes of a Variable-Diameter Rotor System Applied to Civil Tiltrotor Aircraft

The attributes of a variable diameter rotor concept applied to civil tiltrotor aircraft are investigated using the V/STOL aircraft sizing and performance computer program (VASCOMP). To begin, civil tiltrotor viability issues that motivate advanced rotor designs are discussed. Current work on the variable diameter rotor and a theoretical basis for the advantages of the rotor system are presented. The size and performance of variable diameter and conventional tiltrotor designs for the same baseline mission are then calculated using a modified NASA Ames version of VASCOMP. The aircraft are compared based on gross weight, fuel required, engine size, and autorotative performance for various hover disk loading values. Conclusions about the viability of the resulting designs are presented and a program for further variable diameter rotor research is recommended.

Brender, Scott↗

NASA NTRS1998

Dual Liquid Flyback Booster for the Space Shuttle

Liquid Flyback Boosters provide an opportunity to improve shuttle safety, increase performance, and reduce operating costs. The objective of the LFBB study is to establish the viability of a LFBB configuration to integrate into the shuffle vehicle and meet the goals of the Space Shuttle upgrades program. The design of a technically viable LFBB must integrate into the shuffle vehicle with acceptable impacts to the vehicle elements, i.e. orbiter and external tank and the shuttle operations infrastructure. The LFBB must also be capable of autonomous return to the launch site. The smooth integration of the LFBB into the space shuttle vehicle and the ability of the LFBB to fly back to the launch site are not mutually compatible capabilities. LFBB wing configurations optimized for ascent must also provide flight quality during the powered return back to the launch site. This paper will focus on the core booster design and ascent performance. A companion paper 'Conceptual Design for a Space Shuttle Liquid Flyback Booster' will focus on the flyback system design and performance. The LFBB study developed design and aerodynamic data to demonstrate the viability of a dual booster configuration to meet the shuttle upgrade goals, i.e. enhanced safety, improved performance and reduced operations costs.

Blum, C.↗

NASA NTRS1998

Cost and Economics for Advanced Launch Vehicles

Market sensitivity and weight-based cost estimating relationships are key drivers in determining the financial viability of advanced space launch vehicle designs. Due to decreasing space transportation budgets and increasing foreign competition, it has become essential for financial assessments of prospective launch vehicles to be performed during the conceptual design phase. As part of this financial assessment, it is imperative to understand the relationship between market volatility, the uncertainty of weight estimates, and the economic viability of an advanced space launch vehicle program. This paper reports the results of a study that evaluated the economic risk inherent in market variability and the uncertainty of developing weight estimates for an advanced space launch vehicle program. The purpose of this study was to determine the sensitivity of a business case for advanced space flight design with respect to the changing nature of market conditions and the complexity of determining accurate weight estimations during the conceptual design phase. The expected uncertainty associated with these two factors drives the economic risk of the overall program. The study incorporates Monte Carlo simulation techniques to determine the probability of attaining specific levels of economic performance when the market and weight parameters are allowed to vary. This structured approach toward uncertainties allows for the assessment of risks associated with a launch vehicle program's economic performance. This results in the determination of the value of the additional risk placed on the project by these two factors.

Whitfield, Jeff↗