42 research outputs found

    Workshop Report on Ares V Solar System Science

    Get PDF
    The workshop blended three major themes: (1) How can elements of the Constellation program, and specifically, the planned Ares-V heavy-launch vehicle, benefit the planetary community by enabling the launch of large planetary payloads that cannot be launched on existing vehicles, and how can the capabilities of an Ares V allow the planetary community to redesign missions to achieve lower risk, and perhaps lower cost on these missions? (2) What are some of the planetary missions that either can be significantly enhanced or enabled by an Ares-V launch vehicle? What constraints do these mission concepts place on the payload environment of the Ares V? (3) Technology challenges that need to be addressed for launching large planetary payloads. Presentations varied in length from 15-40 minutes. Ample time was provided for discussion

    Titan/Saturn System Mission 2008: Exploring Titan on a Budget (and Without Aerocapture!)

    Get PDF
    This presentation was part of the session : Probe Missions to the Giant Planets, Titan and VenusSixth International Planetary Probe WorkshopTitan has been the topic of a number of mission studies in recent years, culminating in the 2007 Titan Explorer flagship mission study led by APL with JPL participation. This study, as with those previous, made use of the favorable conditions of Titan's atmosphere to allow aerocapture directly into Titan orbit, a technique which would provide over 6 km/s delta-V capability, greatly increasing delivered mass to Titan when compared to purely propulsive options. This year NASA has chosen to continue study of a Titan/Saturn System Mission, but with new ground rules that encourage a quick flight time to Titan while precluding the use of aerocapture. Further direction includes performing Saturn system science (including Enceladus) in addition to purely Titan-focused investigations, as well as a requirement to provide accommodation for a European-provided in-situ vehicle that would be delivered to Titan by the orbiter spacecraft. The financial cap for the US portion of the mission has been set at $2.1B (FY07). The sum of these constraints has resulted in a complete redesign of the Titan mission and flight system, the most notable changes being driven by the necessity of providing a large onboard chemical delta-v capability to take the place of aerocapture. Responding to these constraints, the JPL-APL-ESA/ESTEC team has developed a concept that meets study ground rules and provides an extremely valuable post-Cassini exploration of Titan and the Saturn system. This paper presents an introduction to the challenges, the trades and the resulting mission and flight system concept being developed for this potential outer planets flagship mission.NAS

    Recovering simulated planet and disk signals using SCALES aperture masking

    Full text link
    The Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy (SCALES) instrument is a lenslet-based integral field spectrograph that will operate at 2 to 5 microns, imaging and characterizing colder (and thus older) planets than current high-contrast instruments. Its spatial resolution for distant science targets and/or close-in disks and companions could be improved via interferometric techniques such as sparse aperture masking. We introduce a nascent Python package, NRM-artist, that we use to design several SCALES masks to be non-redundant and to have uniform coverage in Fourier space. We generate high-fidelity mock SCALES data using the scalessim package for SCALES' low spectral resolution modes across its 2 to 5 micron bandpass. We include realistic noise from astrophysical and instrument sources, including Keck adaptive optics and Poisson noise. We inject planet and disk signals into the mock datasets and subsequently recover them to test the performance of SCALES sparse aperture masking and to determine the sensitivity of various mask designs to different science signals

    Simulating medium-spectral-resolution exoplanet characterization with SCALES angular/reference differential imaging

    Full text link
    SCALES (Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy) is a 2 - 5 micron high-contrast lenslet-based integral field spectrograph (IFS) designed to characterize exoplanets and their atmospheres. The SCALES medium-spectral-resolution mode uses a lenslet subarray with a 0.34 x 0.36 arcsecond field of view which allows for exoplanet characterization at increased spectral resolution. We explore the sensitivity limitations of this mode by simulating planet detections in the presence of realistic noise sources. We use the SCALES simulator scalessim to generate high-fidelity mock observations of planets that include speckle noise from their host stars, as well as other atmospheric and instrumental noise effects. We employ both angular and reference differential imaging as methods of disentangling speckle noise from the injected planet signals. These simulations allow us to assess the feasibility of speckle deconvolution for SCALES medium resolution data, and to test whether one approach outperforms another based on planet angular separations and contrasts

    Neptune Odyssey: A Flagship Concept for the Exploration of the Neptune–Triton System

    Get PDF
    The Neptune Odyssey mission concept is a Flagship-class orbiter and atmospheric probe to the Neptune-Triton system. This bold mission of exploration would orbit an ice-giant planet to study the planet, its rings, small satellites, space environment, and the planet-sized moon Triton. Triton is a captured dwarf planet from the Kuiper Belt, twin of Pluto, and likely ocean world. Odyssey addresses Neptune system-level science, with equal priorities placed on Neptune, its rings, moons, space environment, and Triton. Between Uranus and Neptune, the latter is unique in providing simultaneous access to both an ice giant and a Kuiper Belt dwarf planet. The spacecraft - in a class equivalent to the NASA/ESA/ASI Cassini spacecraft - would launch by 2031 on a Space Launch System or equivalent launch vehicle and utilize a Jupiter gravity assist for a 12 yr cruise to Neptune and a 4 yr prime orbital mission; alternatively a launch after 2031 would have a 16 yr direct-to-Neptune cruise phase. Our solution provides annual launch opportunities and allows for an easy upgrade to the shorter (12 yr) cruise. Odyssey would orbit Neptune retrograde (prograde with respect to Triton), using the moon's gravity to shape the orbital tour and allow coverage of Triton, Neptune, and the space environment. The atmospheric entry probe would descend in ~37 minutes to the 10 bar pressure level in Neptune's atmosphere just before Odyssey's orbit-insertion engine burn. Odyssey's mission would end by conducting a Cassini-like "Grand Finale,"passing inside the rings and ultimately taking a final great plunge into Neptune's atmosphere

    PCR-Based assay for differentiation of Pseudomonas aeruginosa from other Pseudomonas species recovered from cystic fibrosis patients

    No full text
    Pseudomonas aeruginosa is the major opportunistic bacterial pathogen in persons with cystic fibrosis (CF); pulmonary infection occurs in approximately 80% of adult CF patients. Much of CF patient management depends on accurate identification of P. aeruginosa from sputum culture. However, identification of this species may be problematic due to the marked phenotypic variability demonstrated by CF sputum isolates and the presence of other closely related species. To facilitate species identification, we used 16S ribosomal DNA (rDNA) sequence data to design PCR assays intended to provide genus- or species-level identification. Both assays yielded DNA fragments of the predicted size. We tested 42 culture collection strains (including 14 P. aeruginosa strains and 28 strains representing 16 other closely related Pseudomonas species) and 43 strains that had been previously identified as belonging to 28 nonpseudomonal species also recovered from CF patient sputum. Based on these 85 strains, the specificity and sensitivity of both assays were 100%. To further assess the utility of the PCR assays, we tested 66 recent CF sputum isolates. The results indicated that preliminary phenotypic testing had misidentified several isolates. The 16S rDNA sequence was determined for 38 isolates, and in all cases it confirmed the results of the PCR assays. Thus, we have designed two PCR assays: one is specific for the genus Pseudomonas, while the other is specific for P. aeruginosa. Both assays show 100% sensitivity and specificity

    Comparative Assessment of Genotyping Methods for Epidemiologic Study of Burkholderia cepacia Genomovar III

    No full text
    We analyzed a collection of 97 well-characterized Burkholderia cepacia genomovar III isolates to evaluate multiple genomic typing systems, including pulsed-field gel electrophoresis (PFGE), BOX-PCR fingerprinting and random amplified polymorphic DNA (RAPD) typing. The typeability, reproducibility, and discriminatory power of these techniques were evaluated, and the results were compared to each other and to data obtained in previous studies by using multilocus restriction typing (MLRT). All methods showed excellent typeability. PFGE with SpeI was more reproducible than RAPD and BOX-PCR fingerprinting. The discriminatory power of the methods was variable, with PFGE and RAPD typing having a higher index of discrimination than BOX-PCR fingerprinting. In general, the results obtained by PFGE, BOX-PCR fingerprinting, and MLRT were in good agreement. Our data indicate that different genomic-based methods can be used to type B. cepacia genomovar III isolates depending on the situation and the epidemiologic question being addressed. PFGE and RAPD fingerprinting are best suited to addressing small-scale studies (i.e., local epidemiology), whereas BOX-PCR fingerprinting is more appropriate for large-scale studies (i.e., global epidemiology). In this regard, BOX-PCR fingerprinting can be considered a rapid and easy alternative to MLRT

    Identification by Subtractive Hybridization of a Novel Insertion Element Specific for Two Widespread Burkholderia cepacia Genomovar III Strains

    No full text
    Species of the Burkholderia cepacia complex cause chronic and life-threatening infections in persons with cystic fibrosis. Epidemic strains infect multiple patients, reside primarily in genomovar III, and have an apparent enhanced capacity for human infection and/or interpatient transmission. By using subtractive hybridization, a novel insertion element, designated IS1363, was identified in epidemic strain PHDC, known to infect many cystic fibrosis patients in the mid-Atlantic region of the United States. IS1363 was also found in most isolates of the ET12 lineage, responsible for infecting large numbers of patients in Ontario, Canada, and the United Kingdom. Southern blot analysis demonstrated that whereas multiple copies of IS1363 were present in strain PHDC, only one copy was present in ET12 isolates. IS1363 was used to probe a collection of 943 B. cepacia complex isolates, representing all nine genomovars, recovered from 761 cystic fibrosis patients or the natural environment. IS1363 was not found in other genomovar III strains and, with the exception of B. ambifaria, was absent from other B. cepacia complex species. Genotyping analyses of all IS1363-positive isolates demonstrated that strain PHDC was more widely distributed in the United States than previously appreciated; 212 cystic fibrosis patients in 24 states were identified as being infected with PHDC
    corecore