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At least 19 records

Dara: Automated Multiple-Hypothesis Phase Identification and Refinement from Powder X-ray Diffraction

Powder X-ray diffraction (XRD) is a foundational technique for characterizing crystalline materials. However, the reliable interpretation of XRD patterns, particularly in multiphase systems, remains a manual and expertise-demanding task. As a characterization method that only provides structural information, multiple reference phases can often be fit to a single pattern, leading to potential misinterpretation when alternative solutions are overlooked. To ease humans’ efforts and address the challenge, we introduce Dara (data-driven automated Rietveld analysis), a framework designed to automate the robust identification and refinement of multiple phases from powder XRD data. Dara performs an exhaustive tree search over all plausible phase combinations within a given chemical space and validates each hypothesis using the BGMN Rietveld refinement routine. Key features include structural database filtering, automatic clustering of isostructural phases during tree expansion, and peak-matching-based scoring to identify promising phases for refinement. When ambiguity exists, Dara generates multiple hypothesis which can then be decided between by human experts or with further characterization tools. By enhancing the reliability and accuracy of phase identification, Dara enables scalable analysis of realistic complex XRD patterns and provides a foundation for integration into multimodal characterization workflows, moving toward fully self-driving materials discovery.

Biological databases

A study of low mass x-ray binaries

The entire effort under this contract during the period through January 1992 was devoted to a study of the cost and schedule required to put an upgraded Aries payload on the ASTRO-SPAS carrier provided by the German space agency, DARA. The ASTRO-SPAS is flown on the Space Shuttle, deployed by the crew for 5 to 7 days of free-flying observations and then recovered and returned to Earth. The spectrograph was to be provided by a collaboration involving the Lockheed Palo Alto Research Laboratory (LPARL), the Center for Astrophysics and Space Astronomy (CASA) at the U. of Colorado and the Mullard Space Science Laboratory (MSSL) in England. The payload for the ASTRO-SPAS mission included our own spectrograph and an instrument provided by Dr. Joachim Trumper of the Max Planck Institute (MPI) in Garching, Germany. A meeting was held in late July, 1991 with German scientists, DARA representatives and MBB, the ASTRO-SPAS spacecraft contractor. Sufficient information was exchanged to allow us to complete the study and the name LEXSA (Low Energy X-ray Spectrograph on ASTRO-SPAS) was given to our instrument and HERTA (High Energy x-Ray Telescope on ASTR0-SPAS) to the German instrument. The combination was called SPECTRO-SPAS. On October 1, 1991 CASA and LPARL submitted a cost and brief technical proposal to NASA on results of the study. The total cost over 4 fiscal years was 6.16 M dollars including CASA costs. NASA Headquarters was briefed on 3 October on details of the proposal. They found our costs reasonable, but indicated that the NASA FY '92 budget is extremely tight, they could not readily identify where the -S2.3M for LEXSA could be found and it was not clear that FY '93 would improve.

Catura, Richard C.

The Next Generation Airborne Observatory: SOFIA

NASA, DARA, and the astronomical community have planned SOFIA (Stratospheric Observatory for Infrared Astronomy) to extend and expand the capabilities of airborne astronomy. Just as the Kuiper Airborne Observatory telescope has three times the aperture of its Learjet predecessor, SOFIA's aperture (2.5 m) will be three times that of the KAO. Thus SOFIA will surpass the angular resolution of the KAO by a factor of three and its per-pixel sensitivity by a factor approximately 10 at wavelengths beyond 10 micrometers. Following the tradition of the KAO and Learjet programs, the user community will provide most of the SOFIA focal plane instruments. Scientists will fly their new instruments as soon as they become operational, assuring immediate application of state-of-the-art technology throughout the anticipated 20 year observatory lifetime. Annual peer review of submitted proposals guarantees a vigorous observing program. Armed by 15-20 different instrument teams, reinforced by an additional approximately 50 guest investigator groups, and flying 160 8-hour sorties per year, SOFIA will be used to attack a very broad range of astronomical problems. To name just a few, observations made from SOFIA will: greatly extend our understanding of the star-formation process, including collapse, accretion, and outflow phenomena; penetrate the obscuring dust of the Milky way to reveal gas motions, the luminosity distribution, and possibly the powerful excitation mechanism at the center of our Galaxy; and probe km-scale structure of planetary atmospheres and ring systems. The Astronomy and Astrophysics Survey (Bahcall) committee ranked SOFIA as the highest priority moderate cost new mission for NASA in the 1990s. SOFIA has been thoroughly studied and is ready to start development. If funding is available in 1996 as currently planned by NASA and DARA Astrophysics Offices, SOFIA could be flying by the end of the decade.

Erickson, E. F.

X-SAR: The X-band synthetic aperture radar on board the Space Shuttle

The X-band synthetic aperture radar (X-SAR) is the German/Italian contribution to the NASA/JPL Shuttle Radar Lab missions as part of the preparation for the Earth Observation System (EOS) program. The Shuttle Radar Lab is a combination of several radars: an L-band (1.2 GHz) and a C-band (5.3 GHz) multipolarization SAR known as SIR-C (Shuttle Imaging Radar); and an X-band (9.6 GHz) vertically polarized SAR which will be operated synchronously over the same target areas to deliver calibrated multifrequency and multipolarization SAR data at multiple incidence angles from space. A joint German/Italian project office at DARA (German Space Agency) is responsible for the management of the X-SAR project. The space hardware has been developed and manufactured under industrial contract by Dornier and Alenia Spazio. Besides supporting all the technical and scientific tasks, DLR, in cooperation with ASI (Agencia Spaziale Italiano) is responsible for mission operation, calibration, and high precision SAR processing. In addition, DLR developed an airborne X-band SAR to support the experimenters with campaigns to prepare for the missions. The main advantage of adding a shorter wavelength (3 cm) radar to the SIR-C radars is the X-band radar's weaker penetration into vegetation and soil and its high sensitivity to surface roughness and associated phenomena. The performance of each of the three radars is comparable with respect to radiometric and geometric resolution.

Werner, Marian U.

The High Resolution Stereo Camera (HRSC) for the Lunar Scout 1 Mission

The High Resolution Stereo Camera (HRSC) is a planetary imaging system developed by the German Aerospace Research Establishment (DLR) with the involvement of the German Space Industry under the leadership of the German Space Agency (DARA) for the Russian Mars 94 and Mars 96 missions. The same instrument, virtually unmodified, is ideal for imaging the Moon. If flown on a Lunar Scout spacecraft, the HRSC will be operated so that it will produce data suitable for generation of a global lunar geodetic net, a global stereo image data set (both data sets produced at an orbit altitude of 200 kms approximately) and high resolution stereo imagery of areas of interest to the scientific community from an orbit altitude of 100 kms (resolution is a function of orbit altitude). All data will be digital.

Neukum, G.

European plans for new clocks in space

An outline of the future European space research program where precise clocks are necessary is presented, pointing out how space applications are posing impressive requirements as regards clock mass, power, ruggedness, long life, accuracy and, in some cases, spectral purity. The material presented was gathered in some laboratories; useful information was obtained from the Space Agencies of France (CNES), Germany (DARA) and Italy (ASI), but the bulk is coming from a recent exercise promoted inside ESA (the European Space Agency) and aimed to prefigure space research activities at the beginning of the next millennium. This exercise was called Horizon 2000 plus; the outcomings were summarized in two reports, presented by ESA in may 1994. Precise clocks and time measurements are needed not only for deep-space or out-ward space missions, but are essential tools also for Earth oriented activities. In this latter field, the European views and needs were discussed in October 1994, in a meeting organized by ESA and devoted to Earth Observation problems. By a scrutiny of these reports, an analysis was performed on the missions requiring a precise clock on board and the driving requirements were pointed out, leading to a survey of the necessary PTTI developments that, to some extent, are in the realm of possibility but that pose serious challenges. In this report the use of frequency standards in the satellite navigation systems is not considered.

Leschiutta, Sigfrido M.

SOFIA: The future of airborne astronomy

For the past 20 years, the 91 cm telescope in NASA's Kuiper Airborne Observatory (KAO) has enabled scientists to observe infrared sources which are obscured by the earth's atmosphere at ground-based sites, and to observe transient astronomical events from anywhere in the world. To augment this capability, the United States and German Space Agencies (NASA and DARA) are collaborating in plans to replace the KAO with a 2.5 meter telescope installed in a Boeing 747 aircraft: SOFIA - The Stratospheric Observatory for Infrared Astronomy. SOFIA's large aperture, wide wavelength coverage, mobility, accessibility, and sophisticated instruments will permit a broad range of scientific studies, some of which are described here. Its unique features complement the capabilities of other future space missions. In addition, SOFIA has important potential as a stimulus for development of new technology and as a national resource for education of K-12 teachers. If started in 1996, SOFIA will be flying in the year 2000.

Erickson, Edwin F.

Second International Microgravity Laboratory (IML-2)

This report highlights the scientific and engineering accomplishments achieved during the 14-day Second International Microgravity Laboratory (IML-2) mission. The mission, managed by the National Aeronautics and Space Administration's Marshall Space Flight Center in Huntsville, Alabama, laid the groundwork for broader international partnerships and scientific alliances. Five other space agencies joined NASA on the mission: the Canadian Space Agency (CSA), the European Space Agency (ESA), the French Space Agency (CNES), the German Space Agency (DARA), and the National Space Development Agency of Japan (NASDA). For the mission, microgravity and life sciences investigations were completed inside Spacelab by a crew working around the clock. The report foreword and introduction describe the mission and the facilities used for IML-2. By the end of the mission, hundreds of primary and secondary experiments were completed. With the help of the principal investigators, most of the primary investigations and some of the co-investigations are described in this document. The lead report authors are cited at the beginning of each experiment description The remainder of the description includes the experiment objectives, flight activities postflight analysis, conclusions, illustrations, and references for further research. The major scientific accomplishments of each investigation are highlighted.

Snyder, Robert S.

Technology

Session WA3 includes short reports concerning: (1) Physiolab A Cardio Vascular Laboratory; (2) MEDEX: A Flexible Modular Physiological Laboratory; (3) A Sensate Liner for Personnel Monitoring Applications; (4) Secure Remote Access to Physiological Data; (5) DARA Vestibular Equipment Onboard MIR; (6) The Kinelite Project: A New powerful Motion Analysis System for Spacelab Mission; (7) The Technical Evolution of the French Neurosciences Multipurpose Instruments Onboard the MIR Station; (8) Extended Ground-Based Research in Preparation for Life Sciences Experiments; and (9) MEDES Clinical Research Facility as a Tool to Prepare ISSA Space Flights.

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Containerless Processing in Reduced Gravity Using the TEMPUS Facility during MSL-1 and MSL-1R

Containerless processing provides a high purity environment for the study of high-temperature, very reactive materials. It is an important method which provides access to the metastable state of an undercooled melt. In the absence of container walls, the nucleation rate is greatly reduced and undercooling up to (Tm-Tn)/Tm approx. equal to 0.2 can be obtained, where Tm and Tn are the melting and nucleation temperatures, respectively. Electromagnetic levitation represents a method particularly well-suited for the study of metallic melts. The TEMPUS (Tiegelfreies ElektroMagnetisches Prozessieren Unter Schwerelosgkeit) facility is a research instrument designed to perform electromagnetic levitation studies in reduced gravity. TEMPUS is a joint undertaking between DARA, the German Space Agency, and the Microgravity Science and Applications Division of NASA. The George C. Marshall Space Flight Center provides the leadership for scientific and management efforts which support the four US PI teams which performed experiments in the TEMPUS facility. The facility is sensitive to accelerations in the 1-10 Hz range. This became evident during the MSL-1 mission. Analysis of accelerometer and video data indicated that loss of sample control occurred during crew exercise periods which created disturbances in this frequency range. Prior to the MSL-1R flight the TEMPUS team, the accelerometer support groups and the mission operations team developed a strategy to provide for the operation of the facility without such disturbances. The successful implementation of this plan led to the highly successful operation of this facility during MSL-1R.

Rogers, Jan R.

STS-99 Crew Activities Report / Flight Day 11 Highlights

The primary objective of the STS-99 mission was to complete high resolution mapping of large sections of the Earth's surface using the Shuttle Radar Topography Mission (STRM), a specially modified radar system. This radar system produced unrivaled 3-D images of the Earth's Surface.. The mission was launched at 12:31 on February 11, 2000 onboard the space shuttle Endeavour. The mission was led by Commander Kevin Kregel. The crew was Pilot Dominic L. Pudwill Gorie and Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri, the National Space Development Agency (Japanese Space Agency) and Gerhard P. J. Thiele, from DARA (German Space Agency). The astronauts finished the mapping operations early on day 11, and then retracted the 200 foot long mast into its payload bay canister. The mast, the longest rigid structure ever deployed in space, supported the external antenna during the mapping operation. The videotape shows the mast folding into the canister. The final stowage was delayed when the three latches on the lid of the canister failed to engage as expected. After a few procedures were executed the mast canister was sealed, on the third attempt, as shown on the videotape. The video also contains several views from the STRM. They include a computerized animation of a flight from Pasadena to Palmdale, a still view of Fiji, a view of the San Francisco Bay Area, and another of Pasadena.

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STS-99 Crew Activities Report / Flight Day 06 Highlights

The primary objective of the STS-99 mission was to complete high resolution mapping of large sections of the Earth's surface using the Shuttle Radar Topography Mission (STRM), a specially modified radar system. This radar system produced unrivaled 3-D images of the Earth's Surface.. The mission was launched at 12:31 on February 11, 2000 onboard the space shuttle Endeavour. The mission was led by Commander Kevin Kregel. The crew was Pilot Dominic L. Pudwill Gorie and Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri, the National Space Development Agency (Japanese Space Agency) and Gerhard P. J. Thiele, from DARA (German Space Agency). This tape shows some of the activities on board the shuttle during day six of the mission. By the end of day six, the mission to map 32 million square miles of the Earth's surface was about 67.2 percent complete. On this video tape there is discussion about the attempts to conserve propellant, to allow for the completion of the planned mapping. There is discussion by Mamoru Mohri about the mission, and Gerhard Thiele answers questions from the German Press about the mission. New radar images from the SRTM of the Kamchatka Peninsula and northwestern Mongolia are shown. There are shots of Endeavour's 200-foot mast, which required troubleshooting due to a balky small thruster.

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STS-99 Crew Arrival for Launch of SRTM, Endeavour

The primary objective of the STS-99 mission was to complete high resolution mapping of large sections of the Earth's surface using the Shuttle Radar Topography Mission (SRTM), a specially modified radar system. This radar system produced unrivaled 3-D images of the Earth's Surface. The mission was launched at 12:31 on February 11, 2000 onboard the space shuttle Endeavour and led by Commander Kevin Kregel. The crew was Pilot Dominic L. Pudwill Gorie and Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri from the National Space Development Agency (Japanese Space Agency), and Gerhard P. J. Thiele from DARA (German Space Agency). This tape shows the arrival of the crew at Kennedy Space Center. After arrival, each of the crew makes a brief statement to the assembled press.

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STS-99 Crew departs SLF after TCDT

The primary objective of the STS-99 mission was to complete high resolution mapping of large sections of the Earth's surface using the Shuttle Radar Topography Mission (SRTM), a specially modified radar system. This radar system produced unrivaled 3-D images of the Earth's Surface. The mission was launched at 12:31 on February 11, 2000 onboard the space shuttle Endeavour. and led by Commander Kevin Kregel. The crew was Pilot Dominic L. Pudwill Gorie and Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri from the National Space Development Agency (Japanese Space Agency), and Gerhard P. J. Thiele from DARA (German Space Agency). This tape shows the astronauts boarding jet planes at the Shuttle Landing Facility after the Terminal Countdown Demonstration Test.

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STS-99 Rollover from OPF-2 to VAB

The primary objective of the STS-99 mission was to complete high resolution mapping of large sections of the Earth's surface using the Shuttle Radar Topography Mission (SRTM), a specially modified radar system. This radar system produced unrivaled 3-D images of the Earth's Surface. The mission was launched at 12:31 on February 11, 2000 onboard the space shuttle Endeavour. and led by Commander Kevin Kregel. The crew was Pilot Dominic L. Pudwill Gorie and Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri from the National Space Development Agency (Japanese Space Agency), and Gerhard P. J. Thiele from DARA (German Space Agency). This tape shows the Endeavour Space Shuttle being rolled over from the Orbiter Processing Facility to the Vertical Assembly building.

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STS-99 Rollout to SRTM 39A

The primary objective of the STS-99 mission was to complete high resolution mapping of large sections of the Earth's surface using the Shuttle Radar Topography Mission (SRTM), a specially modified radar system. This radar system produced unrivaled 3-D images of the Earth's Surface. The mission was launched at 12:31 on February 11, 2000 onboard the space shuttle Endeavour. and led by Commander Kevin Kregel. The crew was Pilot Dominic L. Pudwill Gorie and Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri from the National Space Development Agency (Japanese Space Agency), and Gerhard P. J. Thiele from DARA (German Space Agency). This videotape shows the shuttle with the solid rocket boosters being rolled out to launch pad 39A.

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STS-99 SRTM Lift and Insert into Canister

The primary objective of the STS-99 mission was to complete high resolution mapping of large sections of the Earth's surface using the Shuttle Radar Topography Mission (SRTM), a specially modified radar system. This radar system produced unrivaled 3-D images of the Earth's Surface. The mission was launched at 12:31 on February 11, 2000 onboard the space shuttle Endeavour. and led by Commander Kevin Kregel. The crew was Pilot Dominic L. Pudwill Gorie and Mission Specialists Janet L. Kavandi, Janice E. Voss, Mamoru Mohri from the National Space Development Agency (Japanese Space Agency), and Gerhard P. J. Thiele from DARA (German Space Agency). This videotape shows clean room technicians working on a part of the 200 foot long mast that will hold the SRTM in position during the mission. This videotape also shows the lowering of the SRTM into the canister.

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