Engineering topics
Publications and source records attributed to Norris, J..
The Science Activity Planner (SAP), currently under development by our group at the Jet Propulsion Laboratory, will be the primary tool used for science data assessment and science activity planning during the Mars Exploration Rover (MER) mission.
This paper describes recent field trials performed using the FIDO rover, an advanced NASA technology development platform and research prototype for the next planned rover mission to Mars.
A distributed operations system, the Web Interface for Telescience (WITS), is being developed for use in future planetary lander and rover mission operations.
The Mars Polar Lander (MPL) mission is the first planetary mission to use Internet-based distributed ground operations where scientists and engineers collaborate in daily mission operations from multiple geographically distributed locations via the Internet.
The Mars Polar Lander (MPL) mission is the first planetary mission to use Internet-based distributed ground operations where scientists and engineers collaborate in daily mission operations from multiple geographically distributed locations via the Internet.
The Web Interface for Telescience (WITS) has been developed to provide Internet-based ground operations for planetary lander and rover missions.
This is the final report covering the contract that supported several interrelated task. The first was the calibration of the BATSE SPECtroscopy detectors by comparison with known spectra. The second project was the installation and support of software to enable routine analysis of BATSE data. The third project was the support of several scientific investigations utilizing BATSE flare data.
WEDDS, the WITS Encrypted Data Delivery System, is a framework for supporting distributed mission operations by automatically transferring sensitive mission data in a secure and efficient manner to and from remote mission participants over the internet.
This report reviews activities performed by members of the USRA contract team during the six months of the reporting period and projected activities during the coming six months. Activities take place at the Goddard Space Flight Center, within the Laboratory for High Energy Astrophysics. Developments concern instrumentation, observation, data analysis, and theoretical work in Astrophysics Missions supported include: Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray Timing Experiment (XTE), X-ray Spectrometer (XRS), Astro-E, High Energy Astrophysics Science Archive Research Center (HEASARC), and others.
A series of transients from the galactic bulge direction was observed to have energies intermediate between the x-ray burst and the gamma-ray burst domain. The events are distinct from the 'classical' gamma-ray bursts both in their repeating nature and in their characteristic energy; they are also very brief in duration. This brings to possibly four the historic total number of observed transient series of this type, including the 1979 March 5 event and its sequels, from the direction of N49 in the Large Magellanic Cloud (LMC), and Mazets' B1900+14 series and Babushkina's decade-old observation, both from the galactic disk. It is suggested that these repeaters, unlike the classical bursts with an isotropically distributed source pattern, have sources specifically in high-density galactic and the LMC regions. The evident similarity to the source distributions of x-ray binaries, infrared objects, and visible stars is discussed. The relative intensities and size spectra, the relationship to the anomalous 1979 March 5 event, and other considerations are outlined.
A new photometric technique has been developed for detecting carbon and M stars in distant stellar systems, leading to isolation of carbon-star candidates in a number of Local-Group galaxies. One of the brighter candidates in NGC 6822 has been confirmed spectroscopically; at a distance of approximately 0.5 Mpc, it is the first truly extragalactic carbon star to be positively identified. The star has M(I) = about -5.7 mag, placing it near the upper-luminosity end of known carbon stars in the Magellanic Clouds.
Gamma-ray burst data obtained from the ISEE-3 Gamma Ray Burst Spectrometer and the Solar Maximum Mission's Hard X-ray Burst Spectrometer (HXRBS) were analyzed to yield information on burst temporal and spectral characteristics. A Monte Carlo approach was used to simulate the HXRBS response to candidate spectral models. At energies above about 100 keV, the spectra are well fit by exponential forms. At lower energies, 30 keV to 60 keV, depressions below the model continua are apparent in some bursts. The depressions are not instrumental or data-reduction artifacts. The event selection criterion of the ISEE-3 experiment is based on the time to accumulate a present number of photons rather than the photon count per unit time and is consequently independent of event duration for a given burst intensity, unlike most conventional systems. As a result, a significantly greater percentage of fast, narrow events have been detected. The ratio of count rates from two ISEE-3 detectors indicates that bursts with durations or approx. one second have much softer spectra than longer bursts.