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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS2012

The Advanced X-ray Spectroscopy and Imaging Observatory (AXSIO)

Following recommendations from the 2010 "New Worlds, New Horizons" (NWNH) report, the Advanced X-ray Spectroscopy and Imaging Observatory (AXSIO) concept streamlines the International X-ray Observatory (IXO) mission to concentrate on the science objectives that are enabled by high-resolution spectroscopic capabilities. AXSIO will trace orbits close to the event horizon of black holes, measure black hole spin for tens of supermassive black holes (SMBH), use spectroscopy to characterize outflows and the environment of AGN during their peak activity, observe 5MBH out to redshift z=6, map bulk motions and turbulence in galaxy clusters, find the missing baryons in the cosmic web using background quasars, and observe the process of cosmic feedback where black holes and supernovae inject energy on galactic and intergalactic scales. These measurements are enabled by a 0.9 sq m collecting area at 1.25 keV, a micro calorimeter array providing high-resolution spectroscopic imaging and a deployable high efficiency grating spectrometer. AXSIO delivers a 30-fold increase in effective area for high resolution spectroscopy. The key simplifications are guided by recommendations in the NWNH panel report include a reduction in focal length from 20m to 10m, eliminating the extendable optical bench, and a reduction in the instrument complement from six to two, avoiding a movable instrument platform. A focus on spectroscopic science allows the spatial resolution requirement to be relaxed to 10 arc sec (with a 5 arc sec goal). These simplifications decrease the total mission cost to under the $2B cost to NASA recommended by NWNH. AXSIO will be available to the entire astronomical community with observing allocations based on peer-review.

White, Nicholas E.↗

NASA NTRS2012

Progress and Prospects toward a Space-based Gravitational-Wave Observatory

Over the last few years there has been much activity in the effort to produce a space-based gravitational-wave observatory. These efforts have enriched the understanding of the scientific capabilities of such an observatory leading to broad recognition of its value as an astronomical instrument. At the same time, rapidly developing events in the US and Europe have lead to a more complicated outlook than the baseline Laser Interferometer Space Antenna (LISA) project plan of a few years ago. I will discuss recent progress and developments resulting from the European eLISA study and the SGO study in the US and prospects looking forward.

Baker, John↗

NASA NTRS2012

The Chandra X-Ray Observatory: Progress Report and Highlights

Over the past 13 years, the Chandra X-ray Observatory's ability to provide high resolution X-ray images and spectra have established it as one of the most versatile and powerful tools for astrophysical research in the 21st century. Chandra explores the hot, high-energy regions of the universe, observing X-ray sources with fluxes spanning more than 10 orders of magnitude, from the X-ray brightest, Sco X-1, to the faintest sources in the Chandra Deep Field South survey. Thanks to its continuing operational life, the Chandra mission now also provides a long observing baseline which, in and of itself, is opening new research opportunities. Observations in the past few years alone have deepened our understanding of the co-evolution of supermassive black holes and galaxies, the details of black hole accretion, the nature of dark energy and dark matter, the details of supernovae and their progenitors, the interiors of neutron stars, the evolution of massive stars, and the high-energy environment of protoplanetary nebulae and the interaction of an exo-planet with its star. Here we update the technical status, highlight some of the scientific results, and very briefly discuss future prospects. We fully expect that the Observatory will continue to provide outstanding scientific results for many years to come.

Weisskopf, Martin C.↗

NASA NTRS2012

WFIRST Observatory Performance

The WFIRST observatory will be a powerful and flexible wide-field near-infrared facility. The planned surveys will provide data applicable to an enormous variety of astrophysical science. This presentation will provide a description of the observatory and its performance characteristics. This will include a discussion of the point spread function, signal-to-noise budgets for representative observing scenarios and the corresponding limiting sensitivity. Emphasis will be given to providing prospective Guest Observers with information needed to begin thinking about new observing programs.

Kruk, Jeffrey W.↗

NASA NTRS2013

Automated Long - Term Scheduling for the SOFIA Airborne Observatory

The NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) is a joint US/German project to develop and operate a gyro-stabilized 2.5-meter telescope in a Boeing 747SP. SOFIA's first science observations were made in December 2010. During 2011, SOFIA accomplished 30 flights in the "Early Science" program as well as a deployment to Germany. The new observing period, known as Cycle 1, is scheduled to begin in 2012. It includes 46 science flights grouped in four multi-week observing campaigns spread through a 13-month span. Automation of the flight scheduling process offers a major challenge to the SOFIA mission operations. First because it is needed to mitigate its relatively high cost per unit observing time compared to space-borne missions. Second because automated scheduling techniques available for ground-based and space-based telescopes are inappropriate for an airborne observatory. Although serious attempts have been made in the past to solve part of the problem, until recently mission operations staff was still manually scheduling flights. We present in this paper a new automated solution for generating SOFIA long-term schedules that will be used in operations from the Cycle 1 observing period. We describe the constraints that should be satisfied to solve the SOFIA scheduling problem in the context of real operations. We establish key formulas required to efficiently calculate the aircraft course over ground when evaluating flight schedules. We describe the foundations of the SOFIA long-term scheduler, the constraint representation, and the random search based algorithm that generates observation and instrument schedules. Finally, we report on how the new long-term scheduler has been used in operations to date.

Civeit, Thomas↗

NASA NTRS2013

The Science of Gravitational Waves with Space Observatories

After decades of effort, direct detection of gravitational waves from astrophysical sources is on the horizon. Aside from teaching us about gravity itself, gravitational waves hold immense promise as a tool for general astrophysics. In this talk I will provide an overview of the science enabled by a space-based gravitational wave observatory sensitive in the milli-Hertz frequency band including the nature and evolution of massive black holes and their host galaxies, the demographics of stellar remnant compact objects in the Milky Way, and the behavior of gravity in the strong-field regime. I will also summarize the current status of efforts in the US and Europe to implement a space-based gravitational wave observatory.

Thorpe, James Ira↗

NASA NTRS2013

Modeling Contamination Migration on the Chandra X-ray Observatory II

During its first 14 years of operation, the cold (about ‐60degC) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X‐ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low‐energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition may have changed, perhaps partially related to changes in the operating temperature of the ACIS housing. This evolution of the accumulation of the molecular contamination has motivated further analysis of contamination migration on the Chandra X‐ray Observatory, particularly within and near the ACIS cavity. To this end, the current study employs a higher‐fidelity geometric model of the ACIS cavity, detailed thermal modeling based upon monitored temperature data, and an accordingly refined model of the molecular transport.

O'Dell, Stephen L.↗

NASA NTRS2013

Modeling Contamination Migration on the Chandra X-ray Observatory II

O'Dell, Steve↗

NASA NTRS2013

Aerodynamic and Acoustic Flight Test Results for the Stratospheric Observatory for Infrared Astronomy

As part of the Stratospheric Observatory for Infrared Astronomy (SOFIA) program, a 747SP airplane was modified to carry a 2.5 meter telescope in the aft section of the fuselage. The resulting airborne observatory allows for observations above 99 percent of the water vapor in the atmosphere. The open cavity created by the modifications had the potential to significantly affect the airplane in the areas of aerodynamics and acoustics. Several series of flight tests were conducted to clear the airplanes operating envelope for astronomical observations, planned to be performed between the altitudes of 39,000 feet and 45,000 feet. The flight tests were successfully completed. Cavity acoustics were below design limits, and the overall acoustic characteristics of the cavity were better than expected. The modification did have some effects on the stability and control of the airplane, but these effects were not significant. Airplane air data systems were not affected by the modifications. This paper describes the methods used to examine the aerodynamics and acoustic data from the flight tests and provides a discussion of the flight test results in the areas of cavity acoustics, stability and control, and air data.

SOFIA↗

NASA NTRS2014

Aerodynamic and Acoustic Flight Test Results and Results for the Stratospheric Observatory for Infrared Astronomy

As part of the Stratospheric Observatory for Infrared Astronomy program, a 747SP airplane was modified to carry a 2.5-m telescope in the aft section of the fuselage. The resulting airborne observatory allows for observations above 99 percent of the water vapor in the atmosphere. The open cavity created by the modifications had the potential to significantly affect the airplane in the areas of aerodynamics and acoustics. Several series of flight tests were conducted to clear the operating envelope of the airplane for astronomical observations, planned to be performed between the altitudes of 35,000 ft and 45,000 ft. The flight tests were successfully completed. Cavity acoustics were below design limits, and the overall acoustic characteristics of the cavity were better than expected. The modification did have some effects on the stability and control of the airplane, but these effects were not significant. Airplane air data systems were not affected by the modifications. This paper describes the methods used to examine the aerodynamics and acoustic data from the flight tests and provides a discussion of the flight-test results in the areas of cavity acoustics, stability and control, and air data.

SOFIA↗

NASA NTRS2013

Svetloe Radio Astronomical Observatory

This report summarizes information about the Svetloe Radio Astronomical Observatory activities in 2012. Last year, a number of changes took place in the observatory to improve some technical characteristics and to upgrade some units to their required status. The report provides an overview of current geodetic VLBI activities and gives an outlook for the future.

Smolentsev, Sergey↗

NASA NTRS2013

Zelenchukskaya Radio Astronomical Observatory

This report summarizes information about Zelenchukskaya Radio Astronomical Observatory activities in 2012. Last year a number of changes took place in the observatory to improve some technical characteristics and to upgrade some units to the required status. The report provides an overview of current geodetic VLBI activities and gives an outlook for the future.

Smolentsev, Sergey↗

NASA NTRS2015

A Future Large-Aperture UVOIR Space Observatory: Reference Designs

Our joint NASA GSFC/JPL/MSFC/STScI study team has used community-provided science goals to derive mission needs, requirements, and candidate mission architectures for a future large-aperture, non-cryogenic UVOIR space observatory. We describe the feasibility assessment of system thermal and dynamic stability for supporting coronagraphy. The observatory is in a Sun-Earth L2 orbit providing a stable thermal environment and excellent field of regard. Reference designs include a 36-segment 9.2 m aperture telescope that stows within a five meter diameter launch vehicle fairing. Performance needs developed under the study are traceable to a variety of reference designs including options for a monolithic primary mirror.

exo-planets↗

NASA NTRS2015

Thermal Testing and Model Correlation of the Magnetospheric Multiscale (MMS) Observatories

International Conference on Envronmental Systems (ICES), Seattle WA NCTS 20964-15. The Magnetospheric Multiscale (MMS) mission is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earths magnetosphere as a laboratory tostudy the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration, and turbulence. This paper presents the complete thermal balance (TB) test performed on the first of four observatories to go through thermal vacuum (TV) and the minibalance testing that was performed on the subsequent observatories to provide a comparison of all four. The TV and TB tests were conducted in a thermal vacuum chamber at the Naval Research Laboratory (NRL) in Washington, D.C. with the vacuum level higher than 1.3 x 10-4 Pa (10-6 torr)and the surrounding temperature achieving -180 C. Three TB test cases were performed that included hot operational science, cold operational science and a cold survival case. In addition to the three balance cases a two hour eclipse and a four hour eclipse simulation was performed during the TV test to provide additional transient data points that represent the orbit in eclipse (or Earth's shadow) The goal was to perform testing such that the flight orbital environments could be simulated as closely as possible. A thermal model correlation between the thermal analysis and the test results was completed. Over 400 1-Wire temperature sensors, 200 thermocouples and 125 flight thermistor temperature sensors recorded data during TV and TB testing. These temperatureversus time profiles and their agreements with the analytical results obtained using Thermal Desktop and SINDAFLUINT are discussed. The model correlation for the thermal mathematical model (TMM) is conducted based on the numerical analysis results and the test data. The philosophy of model correlation was to correlate the model to within 3 C of the test data using the standard deviation and mean deviation error calculation. Individual temperature error goal is to be within 5 C and the heater power goal is to be within 5 of test data. The results of the model correlation are discussed and the effect of some material and interface parameters on the temperature profiles are presented.

Thermal↗

NASA NTRS2015

Thermal Testing and Model Correlation of the Magnetospheric Multiscale (MMS) Observatories

The Magnetospheric Multiscale (MMS) mission is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth's magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration, and turbulence. This paper presents the complete thermal balance (TB) test performed on the first of four observatories to go through thermal vacuum (TV) and the minibalance testing that was performed on the subsequent observatories to provide a comparison of all four. The TV and TB tests were conducted in a thermal vacuum chamber at the Naval Research Laboratory (NRL) in Washington, D.C. with the vacuum level higher than 1.3 x 10 (sup -4) pascals (10 (sup -6) torr) and the surrounding temperature achieving -180 degrees Centigrade. Three TB test cases were performed that included hot operational science, cold operational science and a cold survival case. In addition to the three balance cases a two hour eclipse and a four hour eclipse simulation was performed during the TV test to provide additional transient data points that represent the orbit in eclipse (or Earth's shadow) The goal was to perform testing such that the flight orbital environments could be simulated as closely as possible. A thermal model correlation between the thermal analysis and the test results was completed. Over 400 1-Wire temperature sensors, 200 thermocouples and 125 flight thermistor temperature sensors recorded data during TV and TB testing. These temperature versus time profiles and their agreements with the analytical results obtained using Thermal Desktop and SINDA/FLUINT are discussed. The model correlation for the thermal mathematical model (TMM) is conducted based on the numerical analysis results and the test data. The philosophy of model correlation was to correlate the model to within 3 degrees Centigrade of the test data using the standard deviation and mean deviation error calculation. Individual temperature error goal is to be within 5 degrees Centigrade and the heater power goal is to be within 5 percent of test data. The results of the model correlation are discussed and the effect of some material and interface parameters on the temperature profiles are presented.

Correlation↗

NASA NTRS2015

Possible Space-Based Gravitational-Wave Observatory Mission Concept

The existence of gravitational waves was established by the discovery of the Binary Pulsar PSR 1913+16 by Hulse and Taylor in 1974, for which they were awarded the 1983 Nobel Prize. However, it is the exploitation of these gravitational waves for the extraction of the astrophysical parameters of the sources that will open the first new astronomical window since the development of gamma ray telescopes in the 1970's and enable a new era of discovery and understanding of the Universe. Direct detection is expected in at least two frequency bands from the ground before the end of the decade with Advanced LIGO and Pulsar Timing Arrays. However, many of the most exciting sources will be continuously observable in the band from 0.1-100 mHz, accessible only from space due to seismic noise and gravity gradients in that band that disturb ground-based observatories. This poster will discuss a possible mission concept, Space-based Gravitational-wave Observatory (SGO-Mid) developed from the original Laser Interferometer Space Antenna (LISA) reference mission but updated to reduce risk and cost.

Livas, Jeffrey C.↗

NASA NTRS2015

Current Status of a NASA High-Altitude Balloon-Based Observatory for Planetary Science

Recent studies have shown that progress can be made on over 20% of the key questions called out in the current Planetary Science Decadal Survey by a high-altitude balloon-borne observatory. Therefore, NASA has been assessing concepts for a gondola-based observatory that would achieve the greatest possible science return in a low-risk and cost-effective manner. This paper addresses results from the 2014 Balloon Observation Platform for Planetary Science (BOPPS) mission, namely successes in the design and performance of the Fine Pointing System. The paper also addresses technical challenges facing the new Gondola for High Altitude Planetary Science (GHAPS) reusable platform, including thermal control for the Optical Telescope Assembly, power generation and management, and weight-saving considerations that the team will be assessing in 2015 and beyond.

predictive filter↗

NASA NTRS2014

CM5, a Pre-Swarm Comprehensive Geomagnetic Field Model Derived from Over 12 Yr of CHAMP, Orsted, SAC-C and Observatory Data

A comprehensive magnetic field model named CM5 has been derived from CHAMP, Ørsted and SAC-C satellite and observatory hourly-means data from 2000 August to 2013 January using the Swarm Level-2 Comprehensive Inversion (CI) algorithm. Swarm is a recently launched constellation of three satellites to map the Earth's magnetic field. The CI technique includes several interesting features such as the bias mitigation scheme known as Selective Infinite Variance Weighting (SIVW), a new treatment for attitude error in satellite vector measurements, and the inclusion of 3-D conductivity for ionospheric induction. SIVW has allowed for a much improved lithospheric field recovery over CM4 by exploiting CHAMP along-track difference data yielding resolution levels up to spherical harmonic degree 107, and has allowed for the successful extraction of the oceanic M2 tidal magnetic field from quiet, nightside data. The 3-D induction now captures anomalous Solar-quiet features in coastal observatory daily records. CM5 provides a satisfactory, continuous description of the major magnetic fields in the near-Earth region over this time span, and its lithospheric, ionospheric and oceanic M2 tidal constituents may be used as validation tools for future Swarm Level-2 products coming from the CI algorithm and other dedicated product algorithms.

modelling and interpretation↗