Assessment of spore UV and impact resistance of Bacillus pumilus strains isolated from extreme environments
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This paper describes the development and validation of a new methodology for assessing the deleterious effects of spaceflight on crew health and performance. It is well known that microgravity results in various physiological alterations, e.g., headward fluid shifts which can impede physiological adaptation. Other factors that may affect crew operational efficiency include disruption of sleep-wake cycles, high workload, isolation, confinement, stress and fatigue. From an operational perspective, it is difficult to predict which individuals will be most or least affected in this unique environment given that most astronauts are first-time flyers. During future lunar and Mars missions space crews will include both men and women of multi-national origins, different professional backgrounds, and various states of physical condition. Therefore, new methods or technologies are needed to monitor and predict astronaut performance and health, and to evaluate the effects of various countermeasures on crew during long duration missions. This paper reviews several studies conducted in both laboratory and operational environments with men and women ranging in age between 18 to 50 years. The studies included the following: soldiers performing command and control functions during mobile operations in enclosed armored vehicles; subjects participating in laboratory tests of an anti-motion sickness medication; subjects exposed to chronic hypergravity aboard a centrifuge, and subject responses to 36-hours of sleep deprivation. Physiological measurements, performance metrics, and subjective self-reports were collected in each study. The results demonstrate that multivariate converging indicators provide a significantly more reliable method for assessing environmental effects on performance and health than any single indicator.
Even on a bad day, looking down from orbit is a powerful and enjoyable experience, enhanced by the knowledge that time in orbit represents only a tiny fraction of one's life. You look down at Earth and you feel a sense of peace and solidarity. You look at the stars, and because they are not obscured by atmosphere, they are far more abundant than you realized, and they shine very bright. Later on you will reflect on this as one of life's greatest moments. Today astronauts and a few wealthy space tourists have been able to experience staying on the International Space Station. As representatives of humankind in space, astronauts have to get out there and tell people what it's like, and to encourage successive generations of children to consider careers in space. Perhaps the more people who can experience this view, the nicer we will all be to one another. Astronauts must speak authoritatively, without arrogance or a lack of humility. Each astronaut is an emissary who can share his or her experiences and educate people who will not have the opportunity to fly in space. This chapter is a part of that communication process.
Self-healing cable apparatus and methods disclosed. The self-healing cable has a central core surrounded by an adaptive cover that can extend over the entire length of the self-healing cable or just one or more portions of the self-healing cable. The adaptive cover includes an axially and/or radially compressible-expandable (C/E) foam layer that maintains its properties over a wide range of environmental conditions. A tape layer surrounds the C/E layer and is applied so that it surrounds and axially and/or radially compresses the C/E layer. When the self-healing cable is subjected to a damaging force that causes a breach in the outer jacket and the tape layer, the corresponding localized axially and/or radially compressed portion of the C/E foam layer expands into the breach to form a corresponding localized self-healed region. The self-healing cable is manufacturable with present-day commercial self-healing cable manufacturing tools.
This paper reviews the results from two studies that employed the methodology of multiple converging indicators (physiological measures, subjective self-reports and performance metrics) to examine individual differences in the ability of humans to adapt and function in high stress environments. The first study was a joint collaboration between researchers at the US Army Research Laboratory (ARL) and NASA Ames Research Center. Twenty-four men and women active duty soldiers volunteered as participants. Field tests were conducted in the Command and Control Vehicle (C2V), an enclosed armored vehicle, designed to support both stationary and on-the-move operations. This vehicle contains four computer workstations where crew members are expected to perform command decisions in the field under combat conditions. The study objectives were: 1) to determine the incidence of motion sickness in the C2V relative to interior seat orientation/position, and parked, moving and short-haul test conditions; and 2) to determine the impact of the above conditions on cognitive performance, mood, and physiology. Data collected during field tests included heart rate, respiration rate, skin temperature, and skin conductance, self-reports of mood and symptoms, and cognitive performance metrics that included seven subtests in the DELTA performance test battery. Results showed that during 4-hour operational tests over varied terrain motion sickness symptoms increased; performance degraded by at least 5 percent; and physiological response profiles of individuals were categorized based on good and poor cognitive performance. No differences were observed relative to seating orientation or position.
In space, astronauts may experience effects of cumulative sleep loss due to demanding work schedules that can result in cognitive performance impairments, mood state deteriorations, and sleep-wake cycle disruption. Individuals who experience sleep deprivation of six hours beyond normal sleep times experience detrimental changes in their mood and performance states. Hence, the potential for life threatening errors increases exponentially with sleep deprivation. We explored the effects of 36-hours of sleep deprivation on cognitive performance, mood states, and physiological responses to identify which metrics may best predict fatigue induced performance decrements of individuals.
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The atmospheric composition and geologic structure of Venus have been identified by the US National Research Council's Decadal Survey for Planetary Science as priority targets for scientific exploration, however the high temperature and pressure at the surface, along with the highly corrosive chemistry of the Venus atmosphere, present significant obstacles to spacecraft design that have severely limited past and proposed landed missions. Following the methodology of the NASA Innovative Advanced Concepts (NIAC) proposal regime and the Collaborative Modeling and Parametric Assessment of Space Systems (COMPASS) design protocol, this paper presents a conceptual study and initial feasibility analysis for a Discovery-class Venus lander capable of an extended-duration mission at ambient temperature and pressure, incorporating emerging technologies within the field of high temperature electronics in combination with novel configurations of proven, high Technology Readiness Level (TRL) systems. Radioisotope Thermal Power (RTG) systems and silicon carbide (SiC) communications and data handling are examined in detail, and various high-temperature instruments are proposed, including a seismometer and an advanced photodiode imager. The study combines this technological analysis with proposals for a descent instrument package and a relay orbiter to demonstrate the viability of an integrated atmospheric and in-situ geologic exploratory mission that differs from previous proposals by greatly reducing the mass, power requirements, and cost, while achieving important scientific goals.
Harsh environments, such as that on Venus, preclude the use of existing equipment for functions that involve interaction with the environment. The operating limitations of current high temperature electronics are well below the actual temperature and pressure found on Venus (460 deg C and 92 atm), so proposed lander configurations typically include a pressure vessel where the science instruments are kept at Earth-like temperature and pressure (25 deg C and 1 atm). The purpose of this project was to develop and demonstrate a method for sample transfer from an external drill to internal science instruments for a lander on Venus. The initial concepts were string and pneumatically driven systems; and the latter system was selected for its ability to deliver samples at very high speed. The pneumatic system was conceived to be driven by the pressure difference between the Venusian atmosphere and the inside of the lander. The pneumatic transfer of a small capsule was demonstrated, and velocity data was collected from the lab experiment. The sample transfer system was modeled using CAD software and prototyped using 3D printing. General structural and thermal analyses were performed to approximate the proposed system's mass and effects on the temperature and pressure inside of the lander. Additionally, a sampler breadboard for use on Titan was tested and functionality problems were resolved.
This paper describes the mechanical development of patch antenna arrays for the Juno mission. The patch arrays are part of a six-frequency microwave radiometer instrument that will be used to measure thermal emissions from Jupiter. The very harsh environmental conditions in Jupiter orbit, as well as a demanding launch environment, resulted in a design that departs radically from conventional printed circuit patch antennas. The paper discusses the development and qualification of the Juno patch array antennas, with emphasis on the materials approach that was devised to mitigate the effects of electron charging in Jupiter orbit.
The demand to explore new worlds requires the development of advanced technologies that enable landed science on uncertain terrains or in hard to reach locations. As a result, contemporary Entry, Descent, Landing, (EDL) and additional locomotion (EDLL) profiles are becoming increasingly more complex, with the introduction of lifting/guided entries, hazard avoidance on descent, and a plethora of landing techniques including airbags and the skycrane maneuver. The inclusion of each of these subsystems into a mission profile is associated with a substantial mass penalty. This report explores the new all-in-one entry vehicle concept, TANDEM, a new combined EDLL concept, and compares it to the current state of the art EDL systems. The explored system is lightweight and collapsible and provides the capacity for lifting/guided entry, guided descent, hazard avoidance, omnidirectional impact protection and surface locomotion without the aid of any additional subsystems. This Phase I study explored: 1. The capabilities and feasibility of the TANDEM concept as an EDLL vehicle. 2. Extensive impact analysis to ensure mission success in unfavorable landing conditions, and safe landing in Tessera regions. 3. Development of a detailed design for a conceptual mission to Venus. As a result of our work it was shown that: 1. TANDEM provides additional benefits over the Adaptive, Deployable Entry Placement Technology (ADEPT) including guided descent and surface locomotion, while reducing the mass by 38% compared to the ADEPT-VITaL mission. 2. Demonstrated that the design of tensegrity structures, and TANDEM specifically, grows linearly with an increase in velocity, which was previously unknown. 3. Investigation of surface impact revealed a promising results that suggest a properly configured TANDEM vehicle can safely land and preform science in the Tessera regions, which was previously labeled by the Decadal Survey as, largely inaccessible despite its high scientific interest. This work has already resulted in a NASA TM and will be submitted to the Journal of Spacecraft and Rockets.
This report shows how solar power could enable robotic operations in permanently shaded regions at lunar poles, to extract water ice and further produce liquid hydrogen and oxygen (LH2/LO2) propellant. The power needs are derived from an Architecture for Human Exploration of Mars based entirely on lunar propellant. The extraction of 10 metric tons of water per day (at 10% water in regolith) requires approx. 0.6 MW thermal power. Additional approx. 2 MW electric power are required to produce 7.5 metric tons of LH2/LO2 propellant per day, as needed by the architecture. To provide power to processing equipment inside Shackleton Crater, optimal locations are determined on the crater rim, from which several reflecting TransFormers (TFs) would redirect sunlight, achieving a combined period of illumination of approx. 99% of the year. A single 40-m diameter reflector could provide up to 1 MW solar power. Inflatable rigidizable tower support structures raise reflectors above ground for better solar exposure. There are trade-offs: e.g., two reflectors at ground level would provide the same combined total illumination as a single tower approx. 100-m tall. Such a TF based on a 100-m tower made with inflatable 2-m beams and 40-m diameter reflectors would be of similar dimensions as an MSL-class rover (approx. 1000 kg, 10 m(exp 3)). A TF-prospector rover combo could be designed and deployed in a Discovery-class mission searching for water. The TransFormers would be nodes of a Lunar Utilities Infrastructure that provides solar power year-round in the proximity of the pole, as well as local data transmission andintermittent direct to earth communications. This infrastructure would be instrumental infacilitating the development of a lunar economy.
The electrostatic levitation (ESL) laboratory at NASA's Marshall Space Flight Center (MSFC) is a national resource for researchers developing advanced materials for new technologies. Electrostatic levitation minimizes gravitational effects and allows materials to be studied without contact with a container or data-gathering instrumentation.
Sample return missions offer a greater science yield when compared to missions that only employ in situ experiments or remote sensing observations, since they allow the application of more complex technological and analytical methodologies in controlled terrestrial laboratories,that are both repeatable and can be independently verified. The successful return of extraterrestrial materials over the last four decades has contributed to our understanding of the solar system, but retrieval techniques have largely depended on the use of either soft-landing, or touch-and-go procedures that result in high V requirements, larger spacecraft mass ratios, and return yields typically limited to a few grams of surface materials that have experienced varying degrees of alteration from space weathering. Hard-landing methods using planetary penetrators offer an alternative for sample return that significantly reduce a mission's V and mass ratios,increase sample yields, and allow for the collection of subsurface materials, and lessons can be drawn from previous sample return missions. The following details progress in the design,development, and testing of penetrator/sampler technology capable of surviving subsonic and low, supersonic impact velocities (<700 m/s) that would enable the collection of geologic materials using tether technology to return the sample to a passing spacecraft. The testing of energy absorbing material for protecting the sample, design evolution and field testing of the penetrator, and dynamic modeling of tether behavior during sampling are discussed. It is shown through both modeling and field testing that penetrators at speeds between 300-600 m/s (~Mach 1-2) can penetrator into the ground to depths of 1-2 m with overall structural integrity attained.The first flight tests demonstrated the potential for survivability at these speeds. The second flight series demonstrated core sample collection with partial ejection of the sample return canister. The 3rd flight series demonstrated self-ejection of the sample return system fully intact and with the core retaining the full stratigraphy of the rock bed. The tether analysis shows that the forces on the tether during release and return of the sample to the main spacecraft are all at levels that can easily be handled by existing tether materials. The mass analysis of the requirements indicates that sample return form the asteroids could be handled with Discovery or New Frontier range of missions dependent on the number of samples to be returned to the Earth.