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All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

The geocentric orientation vector from limited Astro-geodetic data

Test computations using the comprehensive sets of both astro-geodetic and gravimetric data indicate that the accuracy of the geocentric orientation vector determined from incomplete representations of the earth's gravitational fields, is dependent on the overall extent of the datum. The lack of an astro-geodetic determination of the geoid due to an inadequate density of astro-geodetic stations over certain parts of the datum does not materially affect these determinations. The effect is only marginal if the station density of the area referred to does not markedly differ from the average for the region.

Mather, R. S.↗
NASA NTRS1986

ASTROS - High-performance CCD tracker for spacecraft

The architecture, capabilities, and testing of the Advanced Star and Target Reference Optical Sensor (ASTROS) I and II are described. The ASTROS I tracker is to be utilized for a UV telescope experiment on a Shuttle flight and is capable of measuring pointing errors of 1.5 microrad, and the ASTROS II tracker is being developed for the Mariner Mark II spacecraft to perform tracking, guiding, and optical navigation functions. The requirements for the two trackers are compared. Consideration is given to star and target tracking, optical navigation, and mass and power constraints. The compositions of the trackers, in particular the sensor, electrode drives, amplifiers and signal clamp, video signal processor, control and timing generator, memories, microprocessor, and interface, are examined.

Dennison, E. W.↗
NASA NTRS1987

Ultraviolet observations of starburst systems with Astro and the Hubble Space Telescope

The capabilities of the Astro observatory and the Hubble Space Telescope (HST) for UV astronomical observations are discussed. The advantages of using UV for studying extragalactic problems are reviewed, including sensitivity to hot sources, the rich UV line spectra, sensitivity to interstellar dust, and dark UV sky background. The HST and Astro instrumentation and plans for launching the systems are described. Possibile uses of HST and Astro include the study of massive stars in the Galaxy and nearby galaxies, interstellar medium, the UV excess component in old stellar populations, deep UV surveys (filter imaging and slitless spectroscopy), active galactic nuclei, quasars, and starburst systems.

O'Connell, Robert W.↗
NASA NTRS1991

Astro - Science in the fast lane

The Space Shuttle mission devoted to astronomy (Astro) is described and data obtained during the nine-day flight are briefly reviewed. The Wisconsin Ultraviolet Photo-Polarimeter Experiment reveals a trough at 2200 A in the spectrum of Alpha Camelopardalis. It is suggested that the 2200-A feature is caused by absorption by graphite-rich interstellar dust. The Broad Band X-ray Telescope made it possible to study the NGC 1399 X-ray spectrum, the spectrum of the BL Lacertae object PKS 2155-304, and a cooling flow in a cluster of galaxies. The Astro mission's search for the missing mass in the form of neutrinos is discussed. Attention is also given to the effect of delays on the Astro activity, and to equipment problems and how they were solved.

Maran, Stephen P.↗
NASA NTRS1993

Wide-field direct CCD observations supporting the Astro-1 Space Shuttle mission's Ultraviolet Imaging Telescope

Wide field direct CCD observations are being obtained to support and complement the vacuum-ultraviolet (VUV) images provided by Astro's Ultraviolet Imaging Telescope (UIT) during a Space Shuttle flight in December 1990. Because of the wide variety of projects addressed by UIT, the fields observed include (1) galactic supernova remnants such as the Cygnus Loop and globular clusters such as Omega Cen and M79; (2) the Magellanic Clouds, M33, M81, and other galaxies in the Local Group; and (3) rich clusters of galaxies, principally the Perseus cluster and Abell 1367. Ground-based observations have been obtained for virtually all of the Astro-1 UIT fields. The optical images allow identification of individual UV sources in each field and provide the long baseline in wavelength necessary for accurate analysis of UV-bright sources. To facilitate use of our optical images for analysis of UIT data and other projects, we plan to archive them, with the UIT images, at the National Space Science Data Center (NSSDC), where they will be universally accessible via anonymous FTP. The UIT, one of three telescopes comprising the Astro spacecraft, is a 38-cm f/9 Ritchey-Chretien telescope on which high quantum efficiency, solar-blind image tubes are used to record VUV images on photographic film. Five filters with passbands centered between 1250A and 2500A provide both VUV colors and a measurement of extinction via the 2200A dust feature. The resulting calibrated VUV pictures are 40 arcminutes in diameter at 2.5 arcseconds resolution. The capabilities of UIT, therefore, complement HST's WFPC: the latter has 40 times greater collecting area, while UIT's usable field has 170 times WFPC's field area.

Hintzen, Paul↗
NASA NTRS2004

Intrinsic Line Shape Measurements of the XRS Instrument on Astro-E2

The XRS instrument on the Astro-E2 observatory contains a substantially improved microcalorimeter array over the Astro-E mission. In addition to roughly a factor of 2 improvement in the detector resolution at 6 keV, the detector response is shown to be almost perfectly gaussian. We have made measurements of the detector response of the flight instrument, using a double crystal monochrometer at 4 and 8 keV, a 55-Fe internal conversion source, and x-ray induced fluorescence from a number of targets including Ti, Cu, and GaAs. The detector response has been measured to be entirely gaussian to at least 2 orders of magnitude down from the peak of the line or line complex. This is in sharp contrast to the results from the XRS on Astro-E where many channels exhibited excess counts on the high energy side of the spectral lines. Here we present details of the line shape measurement as well as the detector response as measured during the XRS ground calibration including details of the line fits and line models.

Porter, F. Scott↗
NASA NTRS1993

Astro-D Prelaunch Mission Operation Report (MOR)

The Prelaunch Mission Operation Report for the Astro-D mission is enclosed for your information. Astro-D is a Japanese-led program involving the United States as a participating partner. The Japanese Institute of Space and Astronautical Science (ISAS) provides overall program management, the launch vehicle, the spacecraft, and two Gas Scintillation Imaging System detectors. NASA is providing four nested, thin-foil, grazing-incidence telescope mirrors and two X-ray charged-coupled device solid-state detectors. NASA also provides telemetry tracking support using Deep Space Network ground stations. In return for its scientific instrument contribution, the U.S. will receive 15 percent of the observing time and will share an additional 25 percent for collaborative U.S./Japan scientific investigations. Launch is scheduled for mid- February 1993 from the ISAS launch center near Kagoshima in southern Japan. This MOR: (a) describes the NASA objectives for the Astro-D mission; (b) provides brief descriptions of the spacecraft and its scientific instruments; (c) provides a chronology of launch and deployment; and (d) describes the ground operation elements that support the mission. .

Source record↗
NASA NTRS2018

Ground-Based X-Ray Calibration of the Astro-H/Hitomi Soft X-Ray Telescopes

We present the summary of the on-ground calibration of two soft x-ray telescopes (SXT-I and SXT-S), developed by NASA's Goddard Space Flight Center (GSFC), onboard Astro-H/Hitomi. After the initial x-ray measurements with a diverging beam at the GSFC 100-meter beamline, we performed the full calibration of the x-ray performance, using the 30-meter x-ray beamline facility at the Institute of Space and Astronautical Science of Japan Aerospace Exploration Agency in Japan. We adopted a raster scan method with a narrow x-ray pencil beam with a divergence of approximately 15 arc secs. The on-axis effective area (EA), half-power diameter, and vignetting function were measured at several energies between 1.5 and 17.5 kiloelectronvolts. The detailed results appear in tables and figures in this paper. We measured and evaluated the performance of the SXT-S and the SXT-I with regard to the detector-limited field-of-view and the pixel size of the paired flight detector, i.e., SXS and the SXI, respectively. The primary items measured are the EA, image quality, and stray light for on-axis and off-axis sources. The accurate measurement of these parameters is vital to make the precise response function of the ASTRO-H SXTs. This paper presents the definitive results of the ground-based calibration of the ASTRO-H SXTs.

Iizuka, Ryo↗
NASA NTRS2020

Astro-animation - A case study of art and science education

Art and science are different ways of exploring the world, but together they have the potential to be thought-provoking, facilitate a science‐society dialogue, raise public awareness of science and develop an understanding of art. For several years, we have been teaching an astro-animation class at the Maryland Institute College of Art as a collaboration between students and NASA scientists. Working in small groups, the students create short animations based on the research of the scientists who are going to follow the projects as mentors. By creating these animations, students bring the power of their imagination to see the research of the scientists through a different lens. Astro-animation is an undergraduate-level course jointly taught by an astrophysicist and an animator. In this article, we present the motivation behind the class, describe the details of how it is carried out and discuss the interactions between artists and scientists. We describe how such a programme offers an effective way for art students, not only to learn about science but to have a glimpse of ‘science in action’. The students have the opportunity to become involved in the process of science as artists, as observers first and potentially through their own art research. Every year, one or more internships at NASA Goddard Space Flight Center have been available for our students in the summer. Two students describe their experiences undertaking these internships and how science affects their creation of animations for this programme and in general. We also explain the genesis of our astro-animation programme, how it is taught in our animation department and we present the highlights of an investigation of the effectiveness of this programme we carried out with the support of an NEA research grant. In conclusion, we discuss how the programme may grow in new directions, such as contributing to informal STE(A)M learning.

Laurence Arcadias↗
DOE OSTI2022

ASTRO: Facilitating Advancements in Low-Impact Solar Research, Deployment, and Dissemination

The U.S. Department of Energy's (DOE) InSPIRE project evaluates opportunities for cost reductions and assesses the environmental compatibility of solar energy technologies through low environmental impact designs and approaches. To achieve the project's aim, DOE brings together researchers from the National Renewable Energy Laboratory, Argonne National Laboratory, universities, local governments, environmental groups, and solar industry partners to conduct field-based research complemented by foundational analytical studies. The Agriculture and Solar Together: Research Opportunities (ASTRO) advisory group members come from across the United States and represent leading solar industry partners, state agencies, vegetation management companies, and other organizations focused on research, food and agriculture, and the environment. The ASTRO group of engaged advisors is a complementary combination of organizations creating positive feedback loops that spark and solidify new connections, accelerate information dissemination, and magnify the impact of the InSPIRE project and associated low-impact solar research initiatives.

14 SOLAR ENERGY↗
NASA NTRS2013

Calibration of the Soft X-ray Telescopes (SXT) Onboard the ASTRO-H Satellite

ASTRO-H is an astrophysics satellite dedicated for non-dispersive X-ray spectroscopic study on selective celestial X-ray sources. Among the onboard instruments there are four Wolter-I X-ray mirrors of their reflectors' figure in conical approximation. Two of the four are soft X-ray mirrors, of which the energy range is from a few hundred eV to 15 keV. The focal point instruments will be a calorimeter (SXS) and a CCD camera (SXI), respectively. The mirrors were in quadrant configuration with photons being reflected consecutively in the primary and secondary stage before landing on the focal plane of 5.6 m away from the interface between the two stages. The reflectors of the mirror are made of heat-formed aluminum substrate of the thickness gauged of 152 m, 229 m, and 305 m of the alloy 5052 H-19, followed by epoxy replication on gold-sputtered smooth Pyrex cylindrical mandrels to acquire the X-ray reflective surface. The epoxy layer is 10 m nominal and surface gold layer of 0.2 m. Improvements on angular response over its predecessors, e.g. Astro-E1/Suzaku mirrors, come from error reduction on the figure, the roundness, and the grazing angle/radius mismatching of the reflecting surface, and tighter specs and mechanical strength on supporting structure to reduce the reflector positioning and the assembly errors. Each soft x-ray telescope (SXT), FM1 or FM2, were integrated from four independent quadrants of mirrors. The stray-light baffles, in quadrant configuration, were mounted onto the integrated mirror. Thermal control units were attached to the perimeter of the integrated mirror to keep the mirror within operating temperature in space. The completed instrument went through a series of optical alignment, thus made the quadrant images confocal and their optical axes in parallel to achieve highest throughput possible. Environmental tests were carried out, and optical quality of the telescopes has been confirmed. The optical and x-ray calibrations also include: angular resolution, effective area in the energy range of ~ 0.4 - 12keV, off-axis response, etc. Some of those are being carried out by our counterpart at JAXA/ISAS, Japan. We report the calibration results of the FM1 and FM2 that were obtained at Goddard Space Flight Center.

ASTRO-H Satellite↗
NASA NTRS2016

First Peek of ASTRO-H Soft X-Ray Telescope (SXT) In-Orbit Performance

ASTRO-H (Hitomi) is a Japanese X-ray astrophysics satellite just launched in February, 2016, from Tanegashima, Japan by a JAXA's H-IIA launch vehicle. It has two Soft X-ray Telescopes (SXTs), among other instruments, that were developed by the NASA Goddard Space Flight Center in collaboration with ISAS/JAXA and Nagoya University. One is for an X-ray micro-calorimeter instrument (Soft X-ray Spectrometer, SXS) and the other for an X-ray CCD camera (Soft X-ray Imager, SXI), both covering the X-ray energy band up to 15 keV. The two SXTs were fully characterized at the 30-m X-ray beam line at ISAS/JAXA. The combined SXT+SXS system effective area is about 250 and 300 cm(exp 2) at 1 and 6 keV, respectively, although observations were performed with the gate valve at the dewar entrance closed, which blocks most of low energy X-rays and some of high energy ones. The angular resolution for SXS is 1.2 arcmin (Half Power Diameter, HPD). The combined SXT+SXI system effective area is about 370 and 350 cm (exp 2) at 1 and 6 keV, respectively. The angular resolution for SXI is 1.3 arcmin (HPD). The both SXTs have a field of view of about 16 arcmin (FWHM of their vignetting functions).The SXT+SXS field of view is limited to 3 x 3 arcmin by the SXS array size. In-flight data available to the SXT team was limited at the time of this conference and a point-like source data is not available for the SXT+SXS. Although due to lack of attitude information we were unable to reconstruct a point spread function of SXT+SXI, according to RXJ1856.5-3754 data, the SXT seems to be working as expected in terms of imaging capability. As for the overall effective area response for both SXT+SXS and SXT+SXI, consistent spectral model fitting parameters with the previous measurements were obtained for Crab and G21.5-0.9 data. On the other hand, their 2-10 keV fluxes differ by about 20% at this point. Calibration work is still under progress. The SXT is the latest version of the aluminum foil X-ray mirror, which is extremely light-weight and very low cost, yet produces large effective area over a wide energy-band. Its area-mass ratio is the largest, 16 cm(exp 2)/kg, among ASTRO-H, Chandra, and XMM-Newton mirrors. The aluminum foil mirror is a still compelling technology depending on the mission science goal.

X-rays↗
DOE OSTI2011

Outcomes After Accelerated Partial Breast Irradiation in Patients With ASTRO Consensus Statement Cautionary Features

Purpose: To evaluate outcomes among women with American Society for Radiation Oncology (ASTRO) consensus statement cautionary features treated with brachytherapy-based accelerated partial breast irradiation (APBI). Methods and Materials: Between March 2001 and June 2006, 322 consecutive patients were treated with high-dose-rate (HDR) APBI at the University of Wisconsin. A total of 136 patients were identified who met the ASTRO cautionary criteria. Thirty-eight (27.9%) patients possessed multiple cautionary factors. All patients received 32 to 34 Gy in 8 to 10 twice-daily fractions using multicatheter (93.4%) or Mammosite balloon (6.6%) brachytherapy. Results: With a median follow-up of 60 months, there were 5 ipsilateral breast tumor recurrences (IBTR), three local, and two loco-regional. The 5-year actuarial rate of IBTR was 4.8% {+-} 4.1%. The 5-year disease-free survival was 89.6%, with a cause-specific survival and overall survival of 97.6% and 95.3%, respectively. There were no IBTRs among 32 patients with ductal carcinoma in situ (DCIS) vs. 6.1% for patients with invasive carcinoma (p = 0.24). Among 104 patients with Stage I or II invasive carcinoma, the IBTR rate for patients considered cautionary because of age alone was 0% vs. 12.7% in those deemed cautionary due to histopathologic factors (p = 0.018). Conclusions: Overall, we observed few local recurrences among patients with cautionary features. Women with DCIS and patients 50 to 59 years of age with Stage I/II disease who otherwise meet the criteria for suitability appear to be at a low risk of IBTR. Patients with tumor-related cautionary features will benefit from careful patient selection.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

American Society for Radiation Oncology (ASTRO) 2012 Workforce Study: The Radiation Oncologists' and Residents' Perspectives

Purpose: The American Society for Radiation Oncology (ASTRO) conducted the 2012 Radiation Oncology Workforce Survey to obtain an up-to-date picture of the workforce, assess its needs and concerns, and identify quality and safety improvement opportunities. The results pertaining to radiation oncologists (ROs) and residents (RORs) are presented here. Methods: The ASTRO Workforce Subcommittee, in collaboration with allied radiation oncology professional societies, conducted a survey study in early 2012. An online survey questionnaire was sent to all segments of the radiation oncology workforce. Respondents who were actively working were included in the analysis. This manuscript describes the data for ROs and RORs. Results: A total of 3618 ROs and 568 RORs were surveyed. The response rate for both groups was 29%, with 1047 RO and 165 ROR responses. Among ROs, the 2 most common racial groups were white (80%) and Asian (15%), and the male-to-female ratio was 2.85 (74% male). The median age of ROs was 51. ROs averaged 253.4 new patient consults in a year and 22.9 on-treatment patients. More than 86% of ROs reported being satisfied or very satisfied overall with their career. Close to half of ROs reported having burnout feelings. There was a trend toward more frequent burnout feelings with increasing numbers of new patient consults. ROs' top concerns were related to documentation, reimbursement, and patients' health insurance coverage. Ninety-five percent of ROs felt confident when implementing new technology. Fifty-one percent of ROs thought that the supply of ROs was balanced with demand, and 33% perceived an oversupply. Conclusions: This study provides a current snapshot of the 2012 radiation oncology physician workforce. There was a predominance of whites and men. Job satisfaction level was high. However a substantial fraction of ROs reported burnout feelings. Perceptions about supply and demand balance were mixed. ROs top concerns reflect areas of attention for the healthcare sector as a whole.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Hitomi (ASTRO-H) X-ray Astronomy Satellite

The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. Finally, the paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2017

The State-of-the-art HST Astro-photometric Analysis of the Core of ω Centauri. I. The Catalog

We have constructed the most comprehensive catalog of photometry and proper motions ever assembled for a globular cluster (GC). The core of ω Cen has been imaged over 650 times through WFC3's UVIS and IR channels for the purpose of detector calibration. There exist from 4 to over 60 exposures through each of 26 filters stretching continuously from F225W in the UV to F160W in the infrared. Furthermore, the 11 yr baseline between these data and a 2002 ACS survey has allowed us to more than double the proper-motion accuracy and triple the number of well-measured stars compared to our previous groundbreaking effort. This totally unprecedented complete spectral coverage of over 470,000 stars within the cluster’s core, from the tip of the red giant branch down to the white dwarfs, provides the best astro-photometric observational database yet to understand the multiple-population phenomenon in any GC. In this first paper of the series, we describe in detail the data-reduction processes and deliver the astro-photometric catalog to the astronomical community.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1984

The ASTRO-1 preliminary design review coupled load analysis

Results of the ASTRO-1 preliminary design review coupled loads analysis are presented. The M6.0Y Generic Shuttle mathematical models were used. Internal accelerations, interface forces, relative displacements, and net e.g., accelerations were recovered for two ASTRO-1 payloads in a tandem configuration. Twenty-seven load cases were computed and summarized. Load exceedences were found and recommendations made.

Mcghee, D. S.↗
NASA NTRS1986

The Astro-1 mission

The Astro-1 mission was to be launched in March 1986 for an effective duration of 7 days, chosen to overlap spacecraft encounters with Halley's Comet, i.e., Vega-2 (on 9 March) and Giotto (on 13/14 March). The ultraviolet instrument complement while not designed with cometary research as the prime objective, was well suited to the study of comets. The opportunity of an extended mission during the time of the spacecraft encounters of Halley's Comet offered an extraordinary opportunity for a synergistic interaction between the intercept spacecraft, the Earth-orbital Astro-1 mission, and ground-based observations. The addition of visual-wavelength, wide-field cameras would enhance the scientific return of the mission. Loss of Challenger cancelled the mission.

Brandt, J. C.↗