35 research outputs found
Exploration Medical System Technical Development
The Exploration Medical Capability (ExMC) Element systems engineering goals include defining the technical system needed to implement exploration medical capabilities for Mars. This past year, scenarios captured in the medical system concept of operations laid the foundation for systems engineering technical development work. The systems engineering team analyzed scenario content to identify interactions between the medical system, crewmembers, the exploration vehicle, and the ground system. This enabled the definition of functions the medical system must provide and interfaces to crewmembers and other systems. These analyses additionally lead to the development of a conceptual medical system architecture. The work supports the ExMC community-wide understanding of the functional exploration needs to be met by the medical system, the subsequent development of medical system requirements, and the system verification and validation approach utilizing terrestrial analogs and precursor exploration missions
Exploration Medical System Trade Study Tools Overview
ExMC is creating an ecosystem of tools to enable well-informed medical system trade studies. The suite of tools address important system implementation aspects of the space medical capabilities trade space and are being built using knowledge from the medical community regarding the unique aspects of space flight. Two integrating models, a systems engineering model and a medical risk analysis model, tie the tools together to produce an integrated assessment of the medical system and its ability to achieve medical system target requirements. This presentation will provide an overview of the various tools that are a part of the tool ecosystem. Initially, the presentation's focus will address the tools that supply the foundational information to the ecosystem. Specifically, the talk will describe how information that describes how medicine will be practiced is captured and categorized for efficient utilization in the tool suite. For example, the talk will include capturing what conditions will be planned for in-mission treatment, planned medical activities (e.g., periodic physical exam), required medical capabilities (e.g., provide imaging), and options to implement the capabilities (e.g., an ultrasound device). Database storage and configuration management will also be discussed. The presentation will include an overview of how these information tools will be tied to parameters in a Systems Modeling Language (SysML) model, allowing traceability to system behavioral, structural, and requirements content. The discussion will also describe an HRP-led enhanced risk assessment model developed to provide quantitative insight into each capability's contribution to mission success. Key outputs from these various tools, to be shared with the space medical and exploration mission development communities, will be assessments of medical system implementation option satisfaction of requirements and per-capability contributions toward achieving requirements
Exploration Medical System Technical Architecture Overview
The Exploration Medical Capability (ExMC) Element Systems Engineering (SE) goals include defining the technical system needed to support medical capabilities for a Mars exploration mission. A draft medical system architecture was developed based on stakeholder needs, system goals, and system behaviors, as captured in an ExMC concept of operations document and a system model. This talk will discuss a high-level view of the medical system, as part of a larger crew health and performance system, both of which will support crew during Deep Space Transport missions. Other mission components, such as the flight system, ground system, caregiver, and patient, will be discussed as aspects of the context because the medical system will have important interactions with each. Additionally, important interactions with other aspects of the crew health and performance system are anticipated, such as health & wellness, mission task performance support, and environmental protection. This talk will highlight areas in which we are working with other disciplines to understand these interactions
Preparation of Kepler lightcurves for asteroseismic analyses
The Kepler mission is providing photometric data of exquisite quality for the
asteroseismic study of different classes of pulsating stars. These analyses
place particular demands on the pre-processing of the data, over a range of
timescales from minutes to months. Here, we describe processing procedures
developed by the Kepler Asteroseismic Science Consortium (KASC) to prepare
light curves that are optimized for the asteroseismic study of solar-like
oscillating stars in which outliers, jumps and drifts are corrected.Comment: Accepted for publication in MNRAS. 5 pages, 2 figure
First Kepler results on compact pulsators VIII: Mode identifications via period spacings in mode pulsating Subdwarf B stars
We investigate the possibility of nearly-equally spaced periods in 13 hot
subdwarf B (sdB) stars observed with the Kepler spacecraft and one observed
with CoRoT. Asymptotic limits for gravity (g-)mode pulsations provide
relationships between equal period spacings of modes with differing degrees and
relationships between periods of the same radial order but differing degrees.
Period transforms, Kolmogorov-Smirnov tests, and linear least-squares fits have
been used to detect and determine the significance of equal period spacings. We
have also used Monte Carlo simulations to estimate the likelihood that the
detected spacings could be produced randomly.
Period transforms for nine of the Kepler stars indicate ell=1 period
spacings, with five also showing peaks for ell=2 modes. 12 stars indicate ell=1
modes using the Kolmogorov-Smirnov test while another shows solely ell=2 modes.
Monte Carlo results indicate that equal period spacings are significant in 10
stars above 99% confidence and 13 of the 14 are above 94% confidence. For 12
stars, the various methods find consistent regular period spacing values to
within the errors, two others show some inconsistencies, likely caused by
binarity, and the last has significant detections but the mode assignment
disagrees between methods.
We find a common ell=1 period spacing spanning a range from 231 to 272 s
allowing us to correlate pulsation modes with 222 periodicities and that the
ell=2 period spacings are related to the ell=1 spacings by the asymptotic
relationship . We briefly discuss the impact of equal period
spacings which indicate low-degree modes with a lack of significant mode
trappings.Comment: 27 pages, 4 figures, 17 tables. Accepted for publication in Monthly
Notices of the Royal Astronomical Societ
Detection of Potential Transit Signals in the First Three Quarters of Kepler Mission Data
We present the results of a search for potential transit signals in the first
three quarters of photometry data acquired by the Kepler Mission. The targets
of the search include 151,722 stars which were observed over the full interval
and an additional 19,132 stars which were observed for only 1 or 2 quarters.
From this set of targets we find a total of 5,392 detections which meet the
Kepler detection criteria: those criteria are periodicity of the signal, an
acceptable signal-to-noise ratio, and a composition test which rejects spurious
detections which contain non-physical combinations of events. The detected
signals are dominated by events with relatively low signal-to-noise ratio and
by events with relatively short periods. The distribution of estimated transit
depths appears to peak in the range between 40 and 100 parts per million, with
a few detections down to fewer than 10 parts per million. The detected signals
are compared to a set of known transit events in the Kepler field of view which
were derived by a different method using a longer data interval; the comparison
shows that the current search correctly identified 88.1% of the known events. A
tabulation of the detected transit signals, examples which illustrate the
analysis and detection process, a discussion of future plans and open,
potentially fruitful, areas of further research are included
Overview of the Kepler Science Processing Pipeline
The Kepler Mission Science Operations Center (SOC) performs several critical
functions including managing the ~156,000 target stars, associated target
tables, science data compression tables and parameters, as well as processing
the raw photometric data downlinked from the spacecraft each month. The raw
data are first calibrated at the pixel level to correct for bias, smear induced
by a shutterless readout, and other detector and electronic effects. A
background sky flux is estimated from ~4500 pixels on each of the 84 CCD
readout channels, and simple aperture photometry is performed on an optimal
aperture for each star. Ancillary engineering data and diagnostic information
extracted from the science data are used to remove systematic errors in the
flux time series that are correlated with these data prior to searching for
signatures of transiting planets with a wavelet-based, adaptive matched filter.
Stars with signatures exceeding 7.1 sigma are subjected to a suite of
statistical tests including an examination of each star's centroid motion to
reject false positives caused by background eclipsing binaries. Physical
parameters for each planetary candidate are fitted to the transit signature,
and signatures of additional transiting planets are sought in the residual
light curve. The pipeline is operational, finding planetary signatures and
providing robust eliminations of false positives.Comment: 8 pages, 3 figure
Detection of Potential Transit Signals in Sixteen Quarters of Kepler Mission Data
We present the results of a search for potential transit signals in four
years of photometry data acquired by the Kepler Mission. The targets of the
search include 111,800 stars which were observed for the entire interval and
85,522 stars which were observed for a subset of the interval. We found that
9,743 targets contained at least one signal consistent with the signature of a
transiting or eclipsing object, where the criteria for detection are
periodicity of the detected transits, adequate signal-to-noise ratio, and
acceptance by a number of tests which reject false positive detections. When
targets that had produced a signal were searched repeatedly, an additional
6,542 signals were detected on 3,223 target stars, for a total of 16,285
potential detections. Comparison of the set of detected signals with a set of
known and vetted transit events in the Kepler field of view shows that the
recovery rate for these signals is 96.9%. The ensemble properties of the
detected signals are reviewed.Comment: Accepted by ApJ Supplemen
Kepler-16: A Transiting Circumbinary Planet
We report the detection of a planet whose orbit surrounds a pair of low-mass
stars. Data from the Kepler spacecraft reveal transits of the planet across
both stars, in addition to the mutual eclipses of the stars, giving precise
constraints on the absolute dimensions of all three bodies. The planet is
comparable to Saturn in mass and size, and is on a nearly circular 229-day
orbit around its two parent stars. The eclipsing stars are 20% and 69% as
massive as the sun, and have an eccentric 41-day orbit. The motions of all
three bodies are confined to within 0.5 degree of a single plane, suggesting
that the planet formed within a circumbinary disk.Comment: Science, in press; for supplemental material see
http://www.sciencemag.org/content/suppl/2011/09/14/333.6049.1602.DC1/1210923.Doyle.SOM.pd