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NASA NTRS2010

Launch and Commissioning of the Lunar Reconnaissance Orbiter (LRO)

The Lunar Reconnaissance Orbiter (LRO) launched on June 18, 2009 from the Cape Canaveral Air Force Station. LRO, designed, built, and operated by the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center in Greenbelt, MD, is gathering crucial data on the lunar environment that will help astronauts prepare for long-duration lunar expeditions. To date, the Guidance, Navigation and Control (GN&C) subsystem has operated nominally and met all requirements. However, during the early phase of the mission, the GN&C Team encountered some anomalies. For example, during the Solar Array and High Gain Antenna deployments, one of the safing action points tripped, which was not expected. Also, the spacecraft transitioned to its safe hold mode, SunSafe, due to encountering an end of file for an ephemeris table. During the five-day lunar acquisition, one of the star trackers triggered the spacecraft to transition into a safe hold configuration, the cause of which was determined. These events offered invaluable insight to better understand the performance of the system they designed. An overview of the GN&C subsystem will be followed by a mission timeline. Then, interesting flight performance as well as anomalies encountered by the GN&C Team will be discussed in chronological order.

Shah, Neerav↗
NASA NTRS2010

Analysis of Solar-Heated Thermal Wadis to Support Extended-Duration Lunar Exploration

The realization of the renewed exploration of the Moon presents many technical challenges; among them is the survival of lunar surface assets during periods of darkness when the lunar environment is very cold. Thermal wadis are engineered sources of stored solar energy using modified lunar regolith as a thermal storage mass that can enable the operation of lightweight robotic rovers or other assets in cold, dark environments without incurring potential mass, cost, and risk penalties associated with various onboard sources of thermal energy. Thermal wadi-assisted lunar rovers can conduct a variety of long-duration missions including exploration site surveys; teleoperated, crew-directed, or autonomous scientific expeditions; and logistics support for crewed exploration. This paper describes a thermal analysis of thermal wadi performance based on the known solar illumination of the moon and estimates of producible thermal properties of modified lunar regolith. Analysis was performed for the lunar equatorial region and for a potential Outpost location near the lunar south pole. The results are presented in some detail in the paper and indicate that thermal wadis can provide the desired thermal energy reserve, with significant margin, for the survival of rovers or other equipment during periods of darkness.

Balasubramaniam, R.↗
NASA NTRS2009

Monitoring 2009 Forest Disturbance Across the Conterminous United States, Based on Near-Real Time and Historical MODIS 250 Meter NDVI Products

This case study shows the promise of computing current season forest disturbance detection products at regional to CONUS scales. Use of the eMODIS expedited product enabled a NRT CONUS forest disturbance detection product, a requirement for an eventual, operational forest threat EWS. The 2009 classification product from this study can be used to quantify the areal extent of forest disturbance across CONUS, although a quantitative accuracy assessment still needs to be completed. However, the results would not include disturbances that occurred after July 27, such as the Station Fire. While not shown here, the project also produced maximum NDVI products for the June 10-July 27 period of each year of the 2000-2009 time frame. These products could be applied to compute forest change products on an annual basis. GIS could then be used to assess disturbance persistence. Such follow-on work could lead to attribution of year in which a disturbance occurred. These products (e.g., Figures 6 and 7) may also be useful for assessing forest change associated with climate change, such as carbon losses from bark beetle-induced forest mortality in the Western United States. Other MODIS phenological products are being assessed for aiding forest monitoring needs of the EWS, including cumulative NDVI products (Figure 10).

Spruce, J.↗
NASA NTRS2010

39Ar - 40Ar Studies of Lherzolitic Shergottites Yamato 000097 and 984028

Yamato 984028 (Y984028) was discovered by the Japanese Antarctic Research Expedition (JARE) in 1998 and recently classified as a lherzolitic shergottite with large pyroxene oikocrysts enclosing rounded olivine and chromites. It also contains shock veining and maskelynite. Y984028 is paired with the more recent lherzolitic shergottite finds Y000027/47/97 based on similarities in mineralogy and chemistry, as well as isotopic composition. We present here the studied Ar-39-Ar-40 of Y-984028 whole rock (WR) and pyroxene (Px), in order to gain better understanding of trapped Ar components with a comparison of the possibly-paired Y000097 Ar release.

Park, J.↗
NASA NTRS2002

Mars Surface Environmental Issues

Planetary exploration by astronauts will require extended periods of habitation on a planet's surface, under the influence of environmental factors that are different from those of Earth and the spacecraft that delivered the crew to the planet. Human exploration of Mars, a possible near-term planetary objective, can be considered a challenging scenario. Mission scenarios currently under consideration call for surface habitation periods of from 1 to 18 months on even the earliest expeditions. Methods: Environmental issues associated with Mars exploration have been investigated by NASA and the National Space Biomedical Research Institute (NSBRI) as part of the Bioastronautics Critical Path Roadmap Project (see http ://criticalpath.jsc.nasa.gov). Results: Arrival on Mars will immediately expose the crew to gravity only 38% of that at Earth's surface in possibly the first prolonged exposure to gravity other than the 1G of Earth's surface and the zero G of weightless space flight, with yet unknown effects on crew physiology. The radiation at Mars' surface is not well documented, although the planet's bulk and even its thin atmosphere may moderate the influx of galactic cosmic radiation and energetic protons from solar flares. Secondary radiation from activated components of the soil must also be considered. Ultrafine and larger respirable and nonrespirable particles in Martian dust introduced into the habitat after surface excursions may induce pulmonary inflammation exacerbated by the additive reactive and oxidizing nature of the dust. Stringent decontamination cannot eliminate mechanical and corrosive effects of the dust on pressure suits and exposed machinery. The biohazard potential of putative indigenous Martian microorganisms may be assessed by comparison with analog environments on Earth. Even in their absence, human microorganisms, if not properly controlled, can be a threat to the crew's health. Conclusions: Mars' surface offers a substantial challenge to the health and safety of future human explorers.

Charles, John↗
NASA NTRS2001

A Stream lined Approach for the Payload Customer in Identifying Payload Design Requirements

NASA payload developers from across various disciplines were asked to identify areas where process changes would simplify their task of developing and flying flight hardware. Responses to this query included a central location for consistent hardware design requirements for middeck payloads. The multidisciplinary team assigned to review the numerous payload interface design documents is assessing the Space Shuttle middeck, the SPACEHAB Inc. locker, as well as the MultiPurpose Logistics Module (MPLM) and EXpedite the PRocessing of Experiments to Space Station (EXPRESS) rack design requirements for the payloads. They are comparing the multiple carriers and platform requirements and developing a matrix which illustrates the individual requirements, and where possible, the envelope that encompasses all of the possibilities. The matrix will be expanded to form an overall envelope that the payload developers will have the option to utilize when designing their payload's hardware. This will optimize the flexibility for payload hardware and ancillary items to be manifested on multiple carriers and platforms with minimal impact to the payload developer.

Miller, Ladonna J.↗
NASA NTRS2010

Pieces of Other Worlds - Extraterrestrial Samples for Education and Public Outreach

During the Year of the Solar System spacecraft from NASA and our international partners will encounter two comets; orbit the asteroid Vesta, continue to explore Mars with rovers, and launch robotic explorers to the Moon and Mars. We have pieces of all these worlds in our laboratories, and their continued study provides incredibly valuable "ground truth" to complement space exploration missions. Extensive information about these unique materials, as well as actual lunar samples and meteorites, are available for display and education. The Johnson Space Center (JSC) has the unique responsibility to curate NASA's extraterrestrial samples from past and future missions. Curation includes documentation, preservation, preparation, and distribution of samples for research, education, and public outreach. At the current time JSC curates six types of extraterrestrial samples: (1) Moon rocks and soils collected by the Apollo astronauts (2) Meteorites collected on US expeditions to Antarctica (including rocks from the Moon, Mars, and many asteroids including Vesta) (3) "Cosmic dust" (asteroid and comet particles) collected by high-altitude aircraft (4) Solar wind atoms collected by the Genesis spacecraft (5) Comet particles collected by the Stardust spacecraft (6) Interstellar dust particles collected by the Stardust spacecraft These rocks, soils, dust particles, and atoms continue to be studied intensively by scientists around the world. Descriptions of the samples, research results, thousands of photographs, and information on how to request research samples are on the JSC Curation website: http://curator.jsc.nasa.gov/ NASA provides a limited number of Moon rock samples for either short-term or long-term displays at museums, planetariums, expositions, and professional events that are open to the public. The JSC Public Affairs Office handles requests for such display samples. Requestors should apply in writing to Mr. Louis Parker, JSC Exhibits Manager. Mr. Parker will advise successful applicants regarding provisions for receipt, display, and return of the samples. All loans will be preceded by a signed loan agreement executed between NASA and the requestor's organization. Email address: louis.a.parker@nasa.gov Sets of twelve thin sections of Apollo lunar samples and sets of twelve thin sections of meteorites are available for short-term loan from JSC Curation. The thin sections are designed for use in college and university courses where petrographic microscopes are available for viewing. Requestors should contact the Ms. Mary Luckey, Education Sample Curator. Email address: mary.k.luckey@nasa.gov

Allen, Carlton C.↗
NASA NTRS2000

Human Health and Performance Aspects of the Mars Design Reference Mission

This paper will describe the current planning for exploration-class missions, emphasizing the medical, and human factors aspects of such expeditions. The details of mission architecture are still under study, but a typical Mars design reference mission comprises a six-month transit from Earth to Mar, eighteen months in residence on Mars, and a six-month transit back to Earth. Physiological stressors will include environmental factors such as prolonged exposure to radiation, weightlessness in transit, and hypogravity and a toxic atmosphere while on Mars. Psychological stressors will include remoteness from Earth, confinement, and potential interpersonal conflicts, all complicated by circadian alterations. Medical risks including trauma must also be considered. Results of planning for assuring human health and performance will be presented.

Charles, John B.↗
NASA NTRS2000

The Critical Path Roadmap Project: Biomedical Risk Reduction for Extended Spaceflight

Human exploration of space requires an understanding of the risks to which crews will be exposed during such missions, and the mitigation of those risks to the fullest extent practical. This becomes a greater imperative as we prepare for interplanetary expeditions involving long periods in weightlessness in transit to and then from the destination (a planet, such as Mars, or perhaps a point in space, such as the Lagrangian point L2), and exposure to the unique environment of the destination itself. We need to know, more definitively, what the risks are to human health, safety, and performance, and how to prevent or counteract them throughout all phases of a long duration mission. The Johnson Space Center's Space and Life Sciences Directorate and the National Space Biomedical Research Institute (NSBRI) have implemented an effort to identify the most critical risks confronting humans on such mission and the types of research and technology efforts required to mitigate and otherwise reduce the probability and severity of those risks. This paper describes the "Critical Path Roadmap Project" to define, assess and prioritize the risks and present the results of the assessment with an emphasis on the research and technology priorities to meet the challenge of long duration human spaceflight mission.

Charles, John B.↗
NASA NTRS2010

Digital Microfluidics Sample Analyzer

Three innovations address the needs of the medical world with regard to microfluidic manipulation and testing of physiological samples in ways that can benefit point-of-care needs for patients such as premature infants, for which drawing of blood for continuous tests can be life-threatening in their own right, and for expedited results. A chip with sample injection elements, reservoirs (and waste), droplet formation structures, fluidic pathways, mixing areas, and optical detection sites, was fabricated to test the various components of the microfluidic platform, both individually and in integrated fashion. The droplet control system permits a user to control droplet microactuator system functions, such as droplet operations and detector operations. Also, the programming system allows a user to develop software routines for controlling droplet microactuator system functions, such as droplet operations and detector operations. A chip is incorporated into the system with a controller, a detector, input and output devices, and software. A novel filler fluid formulation is used for the transport of droplets with high protein concentrations. Novel assemblies for detection of photons from an on-chip droplet are present, as well as novel systems for conducting various assays, such as immunoassays and PCR (polymerase chain reaction). The lab-on-a-chip (a.k.a., lab-on-a-printed-circuit board) processes physiological samples and comprises a system for automated, multi-analyte measurements using sub-microliter samples of human serum. The invention also relates to a diagnostic chip and system including the chip that performs many of the routine operations of a central labbased chemistry analyzer, integrating, for example, colorimetric assays (e.g., for proteins), chemiluminescence/fluorescence assays (e.g., for enzymes, electrolytes, and gases), and/or conductometric assays (e.g., for hematocrit on plasma and whole blood) on a single chip platform.

Pollack, Michael G.↗
NASA NTRS2010

Study of the Microbial Diversity of a Newly Discovered East Antarctic Freshwater Lake, L27C, and of a Perennially Ice-Covered Lake Untersee

The microbial communities that reside within freshwater lakes of Schirmacher and Untersee Oases in East Antarctica must cope with extreme conditions that may include cold temperature, annual freeze-thaw cycles, exposure to UV radiation, especially during the austral summer months, low light beneath thick ice-cover, followed by seasonal darkness. The objective of this study was to assess the microbial biodiversity and distribution from samples taken from two freshwater lakes (L27C and Lake Untersee) that were collected during the Tawani 2008 International Antarctic Expedition that conducted research in this region of Antarctica. L27C is a small, previously unreported lake residing 2 km WNW of Maitri Station at Schirmacher Oasis. Biodiversity and distribution of microorganisms within the lake were studied using both culture-independent and culture-dependent methodologies based upon the analysis of eubacterial 16S rRNA gene sequences. Lake Untersee, a perennially ice-covered, ultra-oligotrophic, lake in the Otto-von-Gruber-Gebirge (Gruber Mountains) of central Dronning Maud Land was also sampled and the microbial diversity was analyzed by eubacterial 16S rRNA gene sequences derived from pure cultures. Direct culturing of water samples from each lake on separate R2A growth medium exhibited a variety of microorganisms including: Janthinobacterium, Hymenobacter, Sphingamonas, Subtercola, Deinococcus, Arthrobacter, Flavobacterium, Polaromonas, Rhodoferax and Duganella. The evaluation of samples from L27C through culture-independent methodology identified a rich microbial diversity consisting of six different phyla of bacteria. The culture-independent analysis also displayed the majority of bacteria (56%) belonged to the Class gamma-proteobacteria within the phylum Proteobacteria. Within the Class gamma-proteobacteria, Acinetobacter dominated (48%) the total microbial load. Overall, L27C exhibited 7 different phyla of bacteria and 20 different genera. Statistical analysis (Shannon-Weaver Diversity Index and Simpson Diversity Index) of the biodiversity of L27C displayed a moderately rich and diverse community. Investigations of the biodiversity and distribution of microorganisms in these lakes will help further our understanding of how the physical environment impact the structure and function within these microbially dominated ecosystems.

Huang, Jonathan P.↗
NASA NTRS2010

Human and Robotic Exploration of Near-Earth Objects

A study in late 2006 was sponsored by the Advanced Projects Office within NASA's Constellation Program to examine the feasibility of sending the Orion Crew Exploration Vehicle to a near-Earth object (NEO). The ideal mission profile would involve two or three astronauts on a 90 to 180 day flight, which would include a 7 to 14 day stay for proximity operations at the target NEO. More recently U.S. President Obama stated on April 15, 2010 that the next goal for human spaceflight will be to send human beings to a near-Earth asteroid by 2025. Given this direction from the White House, NASA has been involved in studying various strategies for NEO exploration in order to follow U.S. space exploration policy. Prior to sending a human mission, a series of robotic spacecraft would be launched to reduce the risk to crew, and enhance the planning for the proximity and surface operations at the NEO. The human mission would ideally follow five or more years later. This mission would be the first human expedition to an interplanetary body beyond the Earth-Moon system and would prove useful for testing technologies required for human missions to Mars and other solar system destinations. Piloted missions to NEOs would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific investigations of these primitive objects. The main scientific advantage of sending piloted missions to NEOs would be the flexibility of the crew to perform tasks and to adapt to situations in real time. A crewed vehicle would be able to test several different sample collection techniques and target specific areas of interest via extra-vehicular activities (EVAs) more efficiently than robotic spacecraft. Such capabilities greatly enhance the scientific return from these missions to NEOs, destinations vital to understanding the evolution and thermal histories of primitive bodies during the formation of the early solar system. Data collected from these missions would help constrain the suite of materials possibly delivered to the early Earth, and would identify potential source regions from which NEOs originate. In addition, the resulting scientific investigations would refine designs for future extraterrestrial resource extraction and utilization, and assist in the development of hazard mitigation techniques for planetary defense.

Abell, Paul A.↗
NASA NTRS2010

Cognitive Assessment During Long-Duration Space Flight

The Space Flight Cognitive Assessment Tool for Windows (WinSCAT) is a computer-based, self-administered battery of five cognitive assessment tests developed for medical operations at NASA's Johnson Space Center in Houston, Texas. WinSCAT is a medical requirement for U.S. long-duration astronauts and has been implemented with U.S. astronauts from one NASA/Mir mission (NASA-7 mission) and all expeditions to date on the International Space Station (ISS). Its purpose is to provide ISS crew surgeons with an objective clinical tool after an unexpected traumatic event, a medical condition, or the cumulative effects of space flight that could negatively affect an astronaut's cognitive status and threaten mission success. WinSCAT was recently updated to add network capability to support a 6-person crew on the station support computers. Additionally, WinSCAT Version 2.0.28 has increased difficulty of items in Mathematics, increased number of items in Match-to-Sample, incorporates a moving rather than a fixed baseline, and implements stricter interpretation rules. ISS performance data were assessed to compare initial to modified interpretation rules for detecting potential changes in cognitive functioning during space flight. WinSCAT tests are routinely taken monthly during an ISS mission. Performance data from these ISS missions do not indicate significant cognitive decrements due to microgravity/space flight alone but have shown decrements. Applying the newly derived rules to ISS data results in a number of off-nominal performances at various times during and after flight.. Correlation to actual events is needed, but possible explanations for off-nominal performances could include actual physical factors such as toxic exposure, medication effects, or fatigue; emotional factors including stress from the mission or life events; or failure to exert adequate effort on the tests.

Seaton, Kimberly↗
NASA NTRS2010

Acute and Chronic Exposure to CO2 in Space Flight

Spacecraft and space stations, similar to other habitable confined spaces such as submarines, need to provide a breathable atmosphere for their inhabitants. The inevitable production of CO2 during respiration necessitates life support systems that "scrub" the atmosphere and lower CO2 levels. Due to operational limitations associated with space flight (limited mass, volume, power, and consumables) CO2 is not scrubbed down to its terrestrial equivalent of 0.03% CO2 (ppCO2 of 0.23 mmHg), but is kept below 0.7% (ppCO2 of 5.3 mmHg), a level established in NASA s 180-day mission Spacecraft Maximum Allowable Concentration (SMAC) to be safe and unlikely to cause symptoms. Reports of space flight crewmembers becoming symptomatic with headaches, fatigue, and malaise at levels below those known to cause such symptoms terrestrially has prompted studies measuring the levels of CO2 on both the space shuttle and the space station. Data from cabin atmosphere sampling were collected on space shuttle missions STS-113, STS-122, STS-123, and International Space Station Expeditions 12-15 and 17, and the measured CO2 levels were then correlated to symptoms reported by the crew. The results indicate that a correlation exists between CO2 levels and symptomatology, however causality cannot be established at this time. While the short-term effects of elevated CO2 exposure are well known terrestrially, less is known regarding potential long-term effects of prolonged exposure to a CO2-rich environment or how the physiological changes caused by microgravity may interact with such exposures. Other challenges include limitations in the CO2 monitors used, lack of convection in the microgravity environment, and formation of localized CO2 pockets. As it is unclear if the unique environment of space increases sensitivity to CO2 or if other confounding factors are present, further research is planned to elucidate these points. At the same time, efforts are underway to update the SMAC to a lower level

Alexander, D.↗
NASA NTRS2010

Visual Bias Predicts Gait Adaptability in Novel Sensory Discordant Conditions

We designed a gait training study that presented combinations of visual flow and support-surface manipulations to investigate the response of healthy adults to novel discordant sensorimotor conditions. We aimed to determine whether a relationship existed between subjects visual dependence and their postural stability and cognitive performance in a new discordant environment presented at the conclusion of training (Transfer Test). Our training system comprised a treadmill placed on a motion base facing a virtual visual scene that provided a variety of sensory challenges. Ten healthy adults completed 3 training sessions during which they walked on a treadmill at 1.1 m/s while receiving discordant support-surface and visual manipulations. At the first visit, in an analysis of normalized torso translation measured in a scene-movement-only condition, 3 of 10 subjects were classified as visually dependent. During the Transfer Test, all participants received a 2-minute novel exposure. In a combined measure of stride frequency and reaction time, the non-visually dependent subjects showed improved adaptation on the Transfer Test compared to their visually dependent counterparts. This finding suggests that individual differences in the ability to adapt to new sensorimotor conditions may be explained by individuals innate sensory biases. An accurate preflight assessment of crewmembers biases for visual dependence could be used to predict their propensities to adapt to novel sensory conditions. It may also facilitate the development of customized training regimens that could expedite adaptation to alternate gravitational environments.

Brady, Rachel A.↗
NASA NTRS2010

Gait Adaptability Training Improves Both Postural Stability and Dual-Tasking Ability

After spaceflight, the process of readapting to Earth's gravity commonly presents crewmembers with a variety of locomotor challenges. Our recent work has shown that the ability to adapt to a novel discordant sensorimotor environment can be increased through preflight training, so one focus of our laboratory has been the development of a gait training countermeasure to expedite the return of normal locomotor function after spaceflight. We used a training system comprising a treadmill mounted on a motion base facing a virtual visual scene that provided a variety of sensory challenges. As part of their participation in a larger retention study, 10 healthy adults completed 3 training sessions during which they walked on a treadmill at 1.1 m/s while receiving discordant support-surface and visual manipulations. After a single training session, subjects stride frequencies improved, and after 2 training sessions their auditory reaction times improved, where improvement was indicated by a return toward baseline values. Interestingly, improvements in reaction time came after stride frequency improvements plateaued. This finding suggests that postural stability was given a higher priority than a competing cognitive task. Further, it demonstrates that improvement in both postural stability and dual-tasking can be achieved with multiple training exposures. We conclude that, with training, individuals become more proficient at walking in discordant sensorimotor conditions and are able to devote more attention to competing tasks.

Brady, Rachel A.↗
NASA NTRS2010

Acoustic Noise Prediction of the Amine Swingbed ISS ExPRESS Rack Payload

Acoustics plays a vital role in maintaining the health, safety, and comfort of crew members aboard the International Space Station (ISS). In order to maintain this livable and workable environment, acoustic requirements have been established to ensure that ISS hardware and payload developers account for the acoustic emissions of their equipment and develop acoustic mitigations as necessary. These requirements are verified by an acoustic emissions test of the integrated hardware. The Amine Swingbed ExPRESS (Expedite the PRocessing of ExperimentS to Space) rack payload creates a unique challenge to the developers in that the payload hardware is transported to the ISS in phases, making an acoustic emissions test on the integrated flight hardware impossible. In addition, the payload incorporates a high back pressure fan and a diaphragm vacuum pump, which are recognized as significant and complex noise sources. In order to accurately predict the acoustic emissions of the integrated payload, the individual acoustic noise sources and paths are first characterized. These characterizations are conducted though a series of acoustic emissions tests on the individual payload components. Secondly, the individual acoustic noise sources and paths are incorporated into a virtual model of the integrated hardware. The virtual model is constructed with the use of hybrid method utilizing the Finite Element Acoustic (FEA) and Statistical Energy Analysis (SEA) techniques, which predict the overall acoustic emissions. Finally, the acoustic model is validated though an acoustic characterization test performed on an acoustically similar mock-up of the flight unit. The results of the validated acoustic model are then used to assess the acoustic emissions of the flight unit and define further acoustic mitigation efforts.

Welsh, David↗
NASA NTRS2010

Preliminary Results of Bisphosphonate ISS Flight Experiment

Bone loss has been recognized as a potential problem from the beginning of human spaceflight. With the spaceflight missions lasting 6 months to potentially 3 years or longer this issue has assumed increased significance. Detailed measurements from the Mir and ISS long duration missions have documented losses in bone mineral density (BMD) from the total skeleton and critical sub-regions. The most important losses are from the femoral hip averaging about -1.6%/mo integral to -2.3%/mo trabecular BMD. Importantly these studies have documented the wide range in individual response from -0.5 to -5%/mo in BMD. Given the small size of any expedition crew, the wide range of responses has to be considered in the implementation of any countermeasure. Assuming that it is unlikely that the susceptibility for bone loss in any given crewmember will be known, a suite of bone loss countermeasures will likely be needed to insure protection of all crewmembers. The hypothesis for this experiment is that the combined effect of anti-resorptive drugs plus the standard in-flight exercise regimen will have a measurable effect on preventing space flight induced bone loss and strength and will reduce renal stone risk. To date, 4 crewmembers have completed the flight portion of the protocol in which crewmembers take a 70-mg alendronate tablet once a week before and during flight, starting 17 days before launch. Compared to previous ISS crewmembers (n=14) not taking alendronate, DXA measurements of the total hip BMD were significantly changed from -1.1 0.5%/mo to 0.04 0.3%/mo (p<0.01); QCT-determined trabecular BMD of the total hip was significantly changed from -2.3 1.0%/mo to -0.3 1.6%/mo (p<0.01). Significance was calculated from a one-tailed t test. While these results are encouraging, the current n (4) is small, and the large SDs indicate that while the means are improved there is still high variability in individual response. Four additional crewmembers have been recruited to participate in this experiment, with expected completion of these flights by late 2011.

LeBlanc, Adrian↗