NASA's Goals Research Articles

Carbon and silica fluxes during a declining North Atlantic spring bloom as part of the EXPORTS program

The goal of NASA's EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) project is to develop a predictive understanding of the fate of global ocean primary productivity and export of carbon from the surface to the deep ocean. Thorium-234 (234Th, t1/2 = 24.1 d) was used to measure sinking particle export from an anticyclonic eddy during the EXPORTS North Atlantic cruise (May 2021) at the Porcupine Abyssal Plain. The four-week sampling period was broken into three time periods (“epochs”) where 800 234Th seawater samples were collected from over 50 CTD casts with high depth resolution over the upper 500 m. Size-fractioned particulate samples were collected to determine particulate organic carbon (POC) and biogenic silica (bSi) to 234Th ratios using in situ McLane pumps. A 234Th non-steady state model shows an eddy center epoch average progression of increasing 234Th export (∼2800 ± 300 (Epoch 1; standard deviation) to 4500 ± 700 (Epoch 3) dpm m−2 d−1) out of the top 110 m of the water column over the course of the cruise (29 d). This translates into an epoch average progression of ∼11 ± 1 to 14 ± 2 mmol C m−2 d−1 of sinking POC flux, and ∼ 3 ± 1 to 6 ± 1 mmol bSi m−2 d−1 of sinking bSi flux to deeper waters at 110 m. The overall efficiency of the biological carbon pump (amount of net primary production reaching 100 m below the euphotic zone) increases from ∼10% to ∼30% throughout the sampling period. The temporal trends discussed extensively in this paper show that POC and bSi export increase during diatom bloom evolution.

SHERLOC Raman Mineral Class Detections of the Mars 2020 Crater Floor Campaign

AbstractThe goals of NASA's Mars 2020 mission include searching for evidence of ancient life on Mars, studying the geology of Jezero crater, understanding Mars' current and past climate, and preparing for human exploration of Mars. During the mission's first science campaign, the Perseverance rover's SHERLOC deep UV Raman and fluorescence instrument collected microscale, two‐dimensional Raman and fluorescence images on 10 natural (unabraded) and abraded targets on two different Jezero crater floor units: Séítah and Máaz. We report SHERLOC Raman measurements collected during the Crater Floor Campaign and discuss their implications regarding the origin and history of Séítah and Máaz. The data support the conclusion that Séítah and Máaz are mineralogically distinct igneous units with complex aqueous alteration histories and suggest that the Jezero crater floor once hosted an environment capable of supporting microbial life and preserving evidence of that life, if it existed.

Concept for a space-based near-solar neutrino detector

The concept of putting a neutrino detector in close orbit of the Sun has been unexplored until very recently. The primary scientific return is to vastly enhance our understanding of the solar interior, which is a major NASA goal. Preliminary calculations show that such a spacecraft, if properly shielded, can operate in space environments while taking data from neutrino interactions. These interactions can be distinguished from random background rates of solar electromagnetic emissions, galactic charged cosmic-rays, and gamma-rays by using a double pulsed signature. Early simulations of this project have shown this veto schemes to be successful in eliminating background and identifying the neutrino interaction signal in upwards of 75% of gamma ray interactions and nearly 100% of other interactions. Hence, we propose a new instrument to explore and study the Sun. Due to inverse square scaling, this instrument has the potential to outperform Earth-based experiments in several domains such as making measurements not accessible from the Earth’s orbit.

Hard, not easy

In a speech at Rice University in September 1962, US President John F. Kennedy announced plans for human spaceflight to the Moon by saying, "We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard." These words marked a time when trust in and respect for science were high, and when big questions about the workings of nature were both humbling and inspiring. And although the goals of NASA's Apollo program were not principally to do science, it inspired a generation of scientists. The ensuing years have seen this enthusiasm decline because of failings within as well as outside the world of science, as science is often ridiculed whenever findings lead to political debates. But the successful launch of a remarkable new space telescope this year has rekindled a sense of awe and wonder at the magnificence of the Universe and the thrill of human achievement.

Geotechnical and Shear Behavior of Novel Lunar Regolith Simulants TUBS-M, TUBS-T, and TUBS-I.

The return to the Moon is an important short-term goal of NASA and other international space agencies. To minimize mission risks, technologies, such as rovers or regolith processing systems, must be developed and tested on Earth using lunar regolith simulants that closely resemble the properties of real lunar soil. So far, no singular lunar simulant can cover the multitude of use cases that lunar regolith involves, and most available materials are poorly characterized. To overcome this major gap, a unique modular system for flexible adaptable novel lunar regolith simulants was developed and chemically characterized in earlier works. To supplement this, the present study provides comprehensive investigations regarding geotechnical properties of the three base regolith simulant systems: TUBS-M, TUBS-T, and TUBS-I. To evaluate the engineering and flow properties of these heterogeneous materials under various conditions, shear tests, particle size analyses, scanning electron microscope observations, and density investigations were conducted. It was shown that small grains <25 µm (lunar dust) are highly compressive and cohesive even at low external stress. They are particularly important as a large amount of fine dust is present in lunar regolith and simulants (x50 = 76.7 to 96.0 µm). Further, ring shear and densification tests revealed correlations with damage mechanisms caused by local stress peaks for grains in the mm range. In addition, an explanation for the occurrence of considerable differences in the literature-based data for particle sizes was established by comparing various measurement procedures. The present study shows detailed geotechnical investigations of novel lunar regolith simulants, which can be used for the development of equipment for future lunar exploration missions and in situ resource utilization under realistic conditions. The results also provide evidence about possible correlations and causes of known soil-induced mission risks that so far have mostly been described phenomenologically.

Deep-UV Raman Spectroscopy of Carbonaceous Precambrian Microfossils: Insights into the Search for Past Life on Mars.

The current strategy for detecting evidence of ancient life on Mars-a primary goal of NASA's ongoing Mars 2020 mission-is based largely on knowledge of Precambrian life and of its preservation in Earth's early rock record. The fossil record of primitive microorganisms consists mainly of stromatolites and other microbially influenced sedimentary structures, which occasionally preserve microfossils or other geochemical traces of life. Raman spectroscopy is an invaluable tool for identifying such signs of life and is routinely performed on Precambrian microfossils to help establish their organic composition, degree of thermal maturity, and biogenicity. The Mars 2020 rover, Perseverance, is equipped with a deep-ultraviolet (UV) Raman spectrometer as part of the SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) instrument, which will be used in part to characterize the preservation of organic matter in the ancient sedimentary rocks of Jezero crater and therein search for possible biosignatures. To determine the deep-UV Raman spectra characteristic of ancient microbial fossils, this study analyzes individual microfossils from 14 Precambrian cherts using deep-UV (244 nm) Raman spectroscopy. Spectra obtained were measured and calibrated relative to a graphitic standard and categorized according to the morphology and depositional environment of the fossil analyzed and its Raman-indicated thermal maturity. All acquired spectra of the fossil kerogens include a considerably Raman-enhanced and prominent first-order Raman G-band (∼1600 cm^-1), whereas its commonly associated D-band (∼1350 cm^-1) is restricted to specimens of lower thermal maturity (below greenschist facies) that thus have the less altered biosignature indicative of relatively well-preserved organic matter. If comparably preserved, similar characteristics would be expected to be exhibited by microfossils or ancient organic matter in rock samples collected and cached on Mars in preparation for future sample return to Earth.

Effects of Simulated Long Duration Spaceflight on Erectile Function

The goal of NASA along with other space agencies in the world is to send manned missions to the moon in the coming years, and eventually to Mars. The long‐term health risks of spaceflight have been attributed primarily to cosmic radiation and microgravity and the adverse effects as seen in the astronauts and model animals include DNA damage, mitochondrial dysregulation, oxidative damage, epigenetic changes, telomere length changes and microbiome shifts all of which affect the cardiovascular system. However, little is known about the effect of spaceflight on erectile function which is an important quality of life aspect for men. The aim of our study was to investigate the effect of simulated long duration space flight on erectile function. We hypothesized that both hindlimb unloading (HLU) and radiation will adversely affect erectile function. 86 adult male Sprague‐Dawley rats were used for these studies. Half the animals underwent 4 weeks of HLU, and all animals were divided into 3 groups: those that received sham radiation, 0.75 Gy, and 1.5 Gy galactic cosmic radiation, respectively at the Ground‐based GCR simulator at the NASA Space Radiation laboratory. The animals were then monitored for 6‐9 months before they were sacrificed, following which Corpus cavernosum (CC) and the distal internal pudendal arteries (dIPA) were harvested and used for ex vivo functional assessment. Tissue and wire myography studies were performed to assess adrenergic and endothelium‐dependent vasoconstrictions using phenylephrine (PE), norepinephrine, and endothelin. This was done by measuring the cumulative dose‐responses to the agonists in both the CC and dIPA. Endothelium‐dependent and ‐independent relaxations were also assessed using acetylcholine and diethylamine nononate. Non‐adrenergic non‐cholinergic (NANC) transmission was assessed using electrical stimulation (Estim); 30V electric pulses were delivered to the tissues with frequency ranging from 1‐32Hz following the administration of atropine and guanethidine and pre‐constriction with PE. Finally, Estim was done without atropine and guanethidine to assess the parasympathetic mediated relaxation in the tissues. The effects of HLU and radiation on the contractile and relaxation responses were assessed by two‐way repeated measures ANOVA. HLU and radiation significantly reduced both endothelium‐dependent and ‐independent vasodilatation in the dIPA and CC. Also, HLU and radiation significantly reduced the adrenergic constriction of CC in response to PE and norepinephrine. However, neither HLU nor radiation influenced the endothelium‐dependent vasoconstriction in the dIPA. Finally, radiation reduced the relaxation in both CC and dIPA while HLU increased the dIPA relaxation following Estim for both the parasympathetic mediated and NANC mediated responses. These results therefore showed the effects of HLU and radiation on erectile function, with exposure to cosmic radiation being primarily responsible for the detrimental effects. Further research needs to be done on this subject to show more mechanistically how spaceflight can affect erectile function and ways to combat the problem to ensure that astronauts can return to their normal sexual lives after long trips to space.

Transformation of Cyanobacterial Biomolecules by Iron Oxides During Flash Pyrolysis: Implications for Mars Life-Detection Missions.

Answering the question of whether life ever existed on Mars is a key goal of both NASA's and ESA's imminent Mars rover missions. The obfuscatory effects of oxidizing salts, such as perchlorates and sulfates, on organic matter during thermal decomposition analysis techniques are well established. Less well studied are the transformative effects of iron oxides and (oxy)hydroxides, which are present in great abundances in the martian regolith. We examined the products of flash pyrolysis-gas chromatography-mass spectrometry (a technique analogous to the thermal techniques employed by past, current, and future landed Mars missions) which form when the cyanobacteria Arthrospira platensis are heated in the presence of a variety of Mars-relevant iron-bearing minerals. We found that iron oxides/(oxy)hydroxides have transformative effects on the pyrolytic products of cyanobacterial biomolecules. Both the abundance and variety of molecular species detected were decreased as iron substrates transformed biomolecules, by both oxidative and reductive processes, into lower fidelity alkanes, aromatic and aryl-bonded hydrocarbons. Despite the loss of fidelity, a suite that contains mid-length alkanes and polyaromatic hydrocarbons and/or aryl-bonded molecules in iron-rich samples subjected to pyrolysis may allude to the transformation of cyanobacterially derived mid-long chain length fatty acids (particularly unsaturated fatty acids) originally present in the sample. Hematite was found to be the iron oxide with the lowest transformation potential, and because this iron oxide has a high affinity for codeposition of organic matter and preservation over geological timescales, sampling at Mars should target sediments/strata that have undergone a diagenetic history encouraging the dehydration, dihydroxylation, and oxidation of more reactive iron-bearing phases to hematite by looking for (mineralogical) evidence of the activity of oxidizing, acidic/neutral, and either hot or long-lived fluids.

Investigating the impact of ambient noise on candidate sonic boom metrics

One goal of NASA’s X-59 flight campaign will be to collect low-amplitude sonic boom data over several communities. The combination of lower-amplitude booms with greater ambient noise could pose challenges in measuring and calculating accurate sonic boom perception metrics intended to be correlated with human annoyance. This study uses two NASA sonic boom flight test and simulated X-59 datasets to investigate the impact of limited measurement bandwidth due to ambient noise for multiple candidate metrics. An estimate of the signal-to-noise ratio spectrum allows for the comparison of metrics calculated with full bandwidth, limited bandwidth, and those calculated by applying a low-pass filter that approximates a noise-free full-bandwidth spectrum. The low-pass filter is chosen to approximately match the expected high-frequency roll-off of the sonic booms. Results indicate that Perceived Level and A-weighted sound exposure level are strongly affected by ambient noise and bandwidth limitations, but that B-weighted sound exposure level is much less affected. These results contribute to community noise test planning by demonstrating the ambient noise impact on candidate sonic boom perception metrics. [Work supported by NASA Langley Research Center through National Institute of Aerospace.]

Community Challenges in the Era of Petabyte-Scale Sky Surveys

We outline the challenges faced by the planetary science community in the era of next-generation large-scale astronomical surveys, and highlight needs that must be addressed in order for the community to maximize the quality and quantity of scientific output from archival, existing, and future surveys, while satisfying NASA's and NSF's goals.

An Eye on the Storm: Integrating a Wealth of Data for Quickly Advancing the Physical Understanding and Forecasting of Tropical Cyclones

AbstractTropical cyclones (TCs) are among the most destructive natural phenomena with huge societal and economic impact. They form and evolve as the result of complex multiscale processes and nonlinear interactions. Even today the understanding and modeling of these processes is still lacking. A major goal of NASA is to bring the wealth of satellite and airborne observations to bear on addressing the unresolved scientific questions and improving our forecast models. Despite their significant amount, these observations are still underutilized in hurricane research and operations due to the complexity associated with finding and bringing together semicoincident and semicontemporaneous multiparameter data that are needed to describe the multiscale TC processes. Such data are traditionally archived in different formats, with different spatiotemporal resolution, across multiple databases, and hosted by various agencies. To address this shortcoming, NASA supported the development of the Jet Propulsion Laboratory (JPL) Tropical Cyclone Information System (TCIS)—a data analytic framework that integrates model forecasts with multiparameter satellite and airborne observations, providing interactive visualization and online analysis tools. TCIS supports interrogation of a large number of atmospheric and ocean variables, allowing for quick investigation of the structure of the tropical storms and their environments. This paper provides an overview of the TCIS’s components and features. It also summarizes recent pilot studies, providing examples of how the TCIS has inspired new research, helping to increase our understanding of TCs. The goal is to encourage more users to take full advantage of the novel capabilities. TCIS allows atmospheric scientists to focus on new ideas and concepts rather than painstakingly gathering data scattered over several agencies.

A Terrestrial Validation of ICESat Elevation Measurements and Implications for Global Reanalyses

The primary goal of NASA's Ice, Cloud, and land Elevation Satellite (ICESat) mission was to detect centimeter-level changes in global ice sheet elevations at the spatial scale of individual ice streams. Confidence in detecting these small signals requires careful validation over time to characterize the uncertainty and stability of measured elevations. A common validation approach compares altimeter elevations to an independently characterized and stable reference surface. Using a digital elevation model (DEM) from geodetic surveys of one such surface, the salar de Uyuni in Bolivia, we show that ICESat elevations at this location have a 0.0-cm bias relative to the WGS84 ellipsoid, 4.0-cm (1-sigma) uncertainty overall, and 1.8-cm uncertainty under ideal conditions over short (50 km) profiles. We observe no elevation bias between ascending and descending orbits, but we do find that elevations measured immediately after transitions from low to high surface albedo may be negatively biased. Previous studies have reported intercampaign biases (ICBs) between various ICESat observation campaigns, but we find no statistically significant ICBs or ICB trends in our data. We do find a previously unreported 3.1-cm bias between ICESat's Laser 2 and Laser 3, and we find even larger interlaser biases in reanalyzed data from other studies. For an altimeter with an exact repeat orbit like ICESat, we also demonstrate that validation results with respect to averaged elevation profiles along a single ground track are comparable to results obtained using reference elevations from an in situ survey.

3D Printed and Additively Manufactured RoboSiC™ for Space, Cryogenic, Laser and Nuclear Environments

Abstract Goodman Technologies has been directly responsive to, and focused on, 3D printing and additive manufacturing techniques, and what it takes to manufacture in zero-gravity. During a NASA Phase I SBIR project, using a small multi-printhead machine, we showed that it was possible to formulate and 3D print silicon carbide into shapes appropriate for lightweight mirrors and structures at the production rate of 1.2 square-meter/day. Gradient lattice coupons with feature sizes on the order of 0.8mm were printed and were easily machined to very fine tolerances, ten-thousandths of an inch by Coastline Optics in Camarillo, CA. To further elaborate on the list of achievements, in Phase I, Team GT demonstrated three different ceramization techniques for 3D printing low areal cost, ultra-lightweight Silicon Carbide (SiC) mirrors and structures, radiation shielding, and electronics, several of which could be employed in microgravity The Goodman Technologies briefing presented at 2017 Mirror Technology Days “3D Printed Silicon Carbide Scalable to Meter-Class Segments for Far-Infrared Surveyor: NASA Contract NNX17CM29P along with sample coupons resulted in extreme interest from both Government and the Contractor communities. Our materials, which we call RoboSiC™, is suited for many other applications including heat sinks and radiation shielding for space electronics, and we have already started to make the first parts for these applications. The successful Phase I project suggests that we will meet or exceed all NASA requirements for the primary mirror of a Far-IR Surveyor such as the Origins Space Telescope (OST) and have a high probability solution for the LUVOIR Surveyor in time for the 2020 Decadal Survey. Results indicate that printing on the ground will achieve an areal density of 7.75 kg/square-meter (~39% of a James Webb Space Telescope (JWST) beryllium segment), a cost to print of $60K/segment, and an optical surface that has nanometer-scale tolerances. Printing in the microgravity environment of space we have the potential to achieve an areal density of 1.0–2.0 kg/square meter (&amp;lt;10% of a JWST beryllium segment), with a cost to print of ~$10K/segment. The areal density is 2–15 times better than the NASA goal of 15 kg/square meter, and the costs are substantially better than the NASA goal of $100K/square meter. The encapsulated gradient lattice construction provides a uniform CTE throughout the part for dimensional stability, incredible specific stiffness, and the added benefit of cryo-damping. For the extreme wavefront control required by the Large UV/Optical/IR Surveyor (LUVOIR) the regularly spaced lattice construction should also provide deterministic mapping of any optical distortions directly to the regular actuator spacing of a deformable mirror (DM). Some of our processes will also allow for direct embedding of electronics for active structures and segments. Encapsulation of the lattice structures will allow for actively cooling with helium for unprecedented low emissivity and thermal control. Several decades of experience and testing with SiC have shown that our materials will survive, nay thrive in, the most extreme Space, Cryogenic, Laser and Nuclear Environments.

Assessing the impact of tactical airport surface operations on airline schedule block time setting

With the growth of air traffic, airport surfaces are congested and air traffic operations are disrupted by the formation of bottlenecks on the surface. Hence, improving the efficiency and predictability of airport surface operations is not only a key goal of NASA’s initiatives in Integrated Arrival/Departure/Surface (IADS) operations, but also has been recognized as a critical aspect of the FAA NextGEN implementation plan. While a number of tactical initiatives have been shown to be effective in improving airport surface operations from a service provider’s perspective, their impacts on airlines’ scheduled block time (SBT) setting, which has been found to have direct impact on airlines’ on-time performance and operating cost, have received little attention. In this paper, we assess this impact using an econometric model of airline SBT combined with a before/after analysis of the implementation of surface congestion management (SCM) at John F. Kennedy International Airport (JFK) in 2010. Since airlines do not consider gate delay in setting SBT, we find that reduction in taxi-out time variability resulting from SCM leads to more predictable taxi-out times and thus decreases in SBT. The JFK SCM implementation is used as a case study to validate model prediction performance. The observed SBT decrease between 2009 and 2011 at JFK is 4.8 min and our model predicts a 4.2 min decrease. In addition, Charlotte Douglas International Airport (CLT) is used as an example to demonstrate how different surface operations improvements scenarios can be evaluated in terms of SBT reduction.

Validation of Small Kepler Transiting Planet Candidates in or near the Habitable Zone

Abstract A main goal of NASA’s Kepler Mission is to establish the frequency of potentially habitable Earth-size planets ( ). Relatively few such candidates identified by the mission can be confirmed to be rocky via dynamical measurement of their mass. Here we report an effort to validate 18 of them statistically using the BLENDER technique, by showing that the likelihood they are true planets is far greater than that of a false positive. Our analysis incorporates follow-up observations including high-resolution optical and near-infrared spectroscopy, high-resolution imaging, and information from the analysis of the flux centroids of the Kepler observations themselves. Although many of these candidates have been previously validated by others, the confidence levels reported typically ignore the possibility that the planet may transit a star different from the target along the same line of sight. If that were the case, a planet that appears small enough to be rocky may actually be considerably larger and therefore less interesting from the point of view of habitability. We take this into consideration here and are able to validate 15 of our candidates at a 99.73% (3σ) significance level or higher, and the other three at a slightly lower confidence. We characterize the GKM host stars using available ground-based observations and provide updated parameters for the planets, with sizes between 0.8 and 2.9 R ⊕. Seven of them (KOI-0438.02, 0463.01, 2418.01, 2626.01, 3282.01, 4036.01, and 5856.01) have a better than 50% chance of being smaller than 2 R ⊕ and being in the habitable zone of their host stars.

The future of NASA's missions

Can the recent Discovery mission selections be used as tea leaves to understand the future directions of NASA? In an age of many programmes being used to advance administrative and programmatic goals, Discovery appears to be driven almost entirely by science and by NASA's goal of cheaper missions.

The Effect of High LET Space Radiation on the Human Hematopoietic System: Preliminary Results from the First In Vivo Model

Background: The effects of spaceflight on human physiology are complex and represent a sum of many factors, the main two of which are microgravity and space radiation. The latter is composed of high-energy protons and HZE particles, along with secondary radiation produced in shielding and tissue. One major concern is short- and long-term radiation-induced injury to the hematopoietic system, one of the most radiosensitive tissues in the human body. Previous studies demonstrated functional and/or numerical changes in T and /or B-cells of crewmembers of STS-41B and STS-41D and altered myelopoiesis during STS-63 and STS-69. Although these changes reversed post return, they persisted in space and were more recently documented during a six month mission to the International Space Station. The main goal of NASA's space radiation research program is to enable human space exploration within acceptable risks and to reduce uncertainties regarding risk projections. We present the first ground based in vivo study evaluating the effects of high- and low-LET radiation on the human immune system by using a reconstituted human hematopoietic system in a humanized mouse model. We measure post-radiation depletion and repopulation kinetics, tumor formation and DNA damage.Methods: NSG mice were irradiated with 2Gy of gamma rays and injected 20 hours later with 2x105 CD34+cells isolated from cord blood. After a 12 week engraftment period, peripheral blood flow cytometry with anti-human and anti-mouse antibodies (human and mouse CD45, human CD3 and human CD19) was performed to confirm engraftment (>50% of human cells in moue blood, Figure 1). We irradiated the humanized-NSG mice (hu-NSG) with 0.2 or 0.4 Gy of 350 MeV/n28 Si-ions, which are established components of LET radiation. We measured changes in peripheral blood mononuclear cell counts (huCD45+PBMC) 7 and 30 days post irradiation to assess early effects and recovery kinetics. Multicolor flow cytometric immunophenotyping (FCI) analysis of tissue and blood samples was performed according to standard cell surface staining protocols. Conventional cytogenetic analysis was performed 5 months post radiation on enriched fractions of human HSC and progenitor cells, isolated from marrow of irradiated mice. We performed secondary transplants to transmit the genetic changes imparted by irradiation in the first animal to the secondary host system to allow further monitoring. In addition whole exome and transcriptome sequencing is underway on stem cell and progenitor (lineage negative) pools on a subset of mice.Results: To date 120 well engrafted NSG mice were irradiated with 0.2 or 0.4 Gy of 350 MeV/n28 Si-ions. No decrease versus a mild decrease of huCD45+ PBMCs was observed on day 7 in the 0.2 and 0.4 Gy radiated cohort respectively, with the latter demonstrating full recovery on day 30 compared to normal control mice (Figure 2). No lymphoproliferative or myeloproliferative disorder was noted in 46 irradiated mice using 8 color FCI analyses. Median percentage of peripheral blood mature B-cells, T cells and NK cells was 41%, 36.5% and 9% respectively. Kappa /lambda ratio, CD4/CD8 ratio and NK cell/T cell ratio were 0.9, 3.6, and 0.3 respectively. Bone marrow evaluation demonstrated 0.08% to 0.3% myeloblasts (median: 0.15%) positive for CD34 /CD117/CD33 and HLADR. Moderate monocytosis (CD64+/CD4+/HLA-DR+) was noted, ranging from 39% to 51% (median 47%). Preliminary results of cytogenetic analysis revealed diploid male and female karyotypes without abnormalities in at least 20 metaphases analyzed. Successful secondary transplants were performed in 30 mice. Results of whole exome and transcriptome sequencing are pending.Conclusions: This study shows for first time data on the effects of high -LET space type of radiation on human hematopoietic system in vivo. Preliminary results show that high-LET 350 MeV/n 28 Si radiation has relatively minor effects on peripheral blood cell counts and depletion/recovery kinetics. In addition our preliminary analysis did not demonstrate a leukemogenic effect in the short time period (months) assessed after the irradiation. The study is currently in progress and more data will be available. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Monte Carlo Information-Reuse Approach to Aircraft Conceptual Design Optimization Under Uncertainty

This paper develops a multi-information source formulation for aerospace design under uncertainty problems. As a specific demonstration of the approach, it presents the optimization under uncertainty of an advanced subsonic transport aircraft developed to meet the NASA goals and shows how the multi-information source approach enables practical turnaround time for this conceptual aircraft optimization under uncertainty problem. In the conceptual design phase, there are often uncertainties about future developments of the underlying technologies. An aircraft design that is robust to uncertainty is more likely to meet performance requirements as the technologies mature in the intermediate and detailed design phases, reducing the need for expensive redesigns. In the particular example selected here to present the new approach, the multi-information source approach uses an information-reuse estimator that takes advantage of the correlation of the aircraft model in the design space to reduce the number of model evaluations needed to achieve a given standard error in the Monte Carlo estimates of the relevant design statistics (mean and variance). Another contribution of the paper is to extend the approach to reuse information during trade studies that involve solving multiple optimization under uncertainty problems, enabling the analysis of the risk–performance tradeoff in optimal aircraft designs.

GESE: a small UV space telescope to conduct a large spectroscopic survey of z∼1 Galaxies

One of the key goals of NASA’s astrophysics program is to answer the question: How did galaxies evolve into the spirals and elliptical galaxies that we see today? We describe a space mission concept called Galaxy Evolution Spectroscopic Explorer (GESE) to address this question by making a large spectroscopic survey of galaxies at a redshift, z∼1 (look-back time of ∼8 billion years). GESE is a 1.5-m space telescope with an ultraviolet (UV) multi-object slit spectrograph that can obtain spectra of hundreds of galaxies per exposure. The spectrograph covers the spectral range, 0.2–0.4 μm at a spectral resolving power, R∼500. This observed spectral range corresponds to 0.1–0.2 μm as emitted by a galaxy at a redshift, z=1. The mission concept takes advantage of two new technological advances: (1) light-weighted, wide-field telescope mirrors, and (2) the Next-Generation MicroShutter Array (NG-MSA) to be used as a slit generator in the multi-object slit spectrograph.

Methodology for Sizing and Performance Assessment of Hybrid Energy Aircraft

The Strategic Research and Innovation Agenda and NASA goals have set new challenges for the aeronautical community via declaration of dramatic efficiency improvements. Because further evolutionary improvements do not appear to be sufficient, envisioning disruptive technologies turn out to be essential to reach the set of future targets. The design of innovative integrated energy–power systems is certainly a major promising element as can be shown by the increasing interest toward hybrid energy and universally electric aircraft. The consideration of these new types of aircraft represents a new challenge for conventional aircraft sizing and performance methods. As an extension of the conventional methods used for fuel-energy aircraft, a sizing and performance methodology for hybrid-energy aircraft is proposed. A design study of a battery and fuel hybrid-energy single-aisle retrofit is conducted to demonstrate the methodology and to analyze the implications of the associated new design variables on the sizing and performance. The benchmark against a conventional reference aircraft shows a potential block fuel-burn reduction up to 16% for a 900 n mile off-design mission stage length (using a mix of fuel energy to electrical energy of ). Clean sheet designs will be part of future work to assess the full potential of hybrid-energy aircraft.