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N89-28461*# Maryland Univ., College Park. Dept. of Physics
The Parallel Architectures for Planetary Exploration Requirements (PAPER) project is essentially research oriented towards technology insertion issues for NASA's unmanned planetary probes. It was initiated to complement and augment the long-term efforts for space exploration with particular reference to NASA/LaRC's (NASA Langley Research Center) research needs for planetary exploration missions of the mid and late 1990s. The requirements for space missions as given in the somewhat dated Advanced Information Processing Systems (AIPS) requirements document are contrasted with the new requirements from JPL/Caltech involving sensor data capture and scene analysis. It is shown that more stringent requirements have arisen as a result of technological advancements. Two possible architectures, the AIPS Proof of Concept (POC) configuration and the MAX Fault-tolerant dataflow multiprocessor, were evaluated. The main observation was that the AIPS design is biased towards fault tolerance and may not be an ideal architecture for planetary and deep space probes due to high cost and complexity. The MAX concepts appears to be a promising candidate, except that more detailed information is required. The feasibility for adding neural computation capability to this architecture needs to be studied. Key impact issues for architectural design of computing systems meant for planetary missions were also identified.
N89-28462*# National Oceanic and Atmospheric Administration,
N89-28463* # Air Force Geophysics Lab., Hanscom AFB, MA. PREDICTING THE ARRIVAL TIMES OF SOLAR PARTICLES D. F. Smart In Jet Propulsion Lab., California Inst. of Tech., Interplanetary Particle Environment. Proceedings of a Conference 15 Apr. 1988 P 101-110 (For primary document see N89-28454 22-90) Avail: NTIS HC A08/MF A01 CSCL 03B
92 SOLAR PHYSICS
Includes solar activity, solar flares, solar radiation and sunspots.
For related information see 93 Space Radiation.
N89-28476*# Smithsonian Astrophysical Observatory, Cambridge, MA. CORONAGRAPH OBSERVATIONS AND ANALYSES OF THE ULTRAVIOLET SOLAR CORONA Semiannual Status Report, 1 Apr. 1987 - 31 Mar. 1989 John L. Kohl Mar. 1989 20 p (Grant NAG5-613) (NASA-CR-185830; NAS 1.26:185830; SASR-10; SASR-11; SASR-12; SASR-13) Avail: NTIS HC A03/MF A01 CSCL 03B
The major activities on the Spartan Ultraviolet Coronal Spectrometer project include both scientific and experimental/ technical efforts. In the scientific area, a detailed analysis of the previously reported Doppler dimming of HI Ly-alpha from the July 1982 rocket flight has determined an outflow velocity at 2 solar radii from sun center to be between 153 and 251 km/s at 67 percent confidence. The technical activities include, several improvements made to the instrument that will result in enhanced scientific performance or in regaining a capability that had deteriorated during the delay time in the launch date. These include testing and characterizing the detector for OVI radiation, characterizing a serrated occulter at UV and visible wavelengths, fabricating and testing telescope mirrors with improved edges, testing and evaluating a new array detector system, modifying the slit mask mechanism and installing a mask in the instrument to block the Ly-alpha resonance line when the electron scattered component is being observed.
93 SPACE RADIATION
Includes cosmic radiation; and inner and outer earth's radiation belts.
For biological effects of radiation see 52 Aerospace Medicine. For theory see 73 Nuclear and High-Energy Physics.
N89-28477# Lawrence Livermore National Lab., CA. Dept. of Physics. GAMMA RAY BURSTS: CONFRONTATION BETWEEN THEORY AND OBSERVATIONAL DATA Edison P. Liang 15 May 1989 21 p Presented at the Gamma Ray Observatory Science Workshop, Greenbelt, MD, 10-12 Apr. 1989 (Contract W-7405-eng-48) (DE89-012936; UCRL-101121; CONF-8904216-3) Avail: NTIS HC A03/MF A01
The current observational data and theoretical models of cosmic gamma ray bursts are reviewed. The evidences for and physics issues of a teragauss field neutron star interpretation are summarized. Constraints on the baseline emission scenario are highlighted. A brief comparison is given of some popular astrophysical models. Some priorities for future observations and data analyses are suggested.
N89-28460*# Air Force Geophysics Lab., Hanscom AFB, MA.
N89-28478# Oak Ridge National Lab., TN. Biology Div.
Presented at the Symposium on Radiation Hazards in Space and Biological Consequences, Washington, DC, 11 May 1989 Sponsored in part by Martin Marietta Energy Systems, Inc. (Contract DE-AC05-840R-21400) (DE89-013043; CONF-8905157-1) Avail: NTIS HC A03/MF A01
The radiation dose rates in low-earth orbits are dependent on the altitude and orbital inclination. The doses to which the crews of space vehicles are exposed is governed by the duration of the mission and the shielding, and in low-earth orbit missions protons are the dominant particles encountered. The risk of concern with the low dose rates and the relatively low total doses of radiation that will be incurred on the space station is excess cancer. The National Council on Radiation Protection and Measurements has recently recommended career dose-equivalent limits that take into account sex and age. The new recommendations for career limits range from 1.0 Sv to 4 Sv, depending on sex and on the age at the time of their first space mission, compared to a single career limit of 4.0 Sv previously used by NASA. Risk estimates for radiated-induced cancer are evolving and changes in the current guidance may be required in the next few years.
at distances as close as about 350 km. Nuclear line features were observed in the gamma-ray spectrum. Explanations for some of these features are presented. The absolute power of the reactor is difficult to estimate at present; however, there is evidence that both the intensity and spectral shape of the emitted radiation changed significantly during the operational period of COSMOS. The reactor was also detected at distances of greater than or 6,300 km in an indirect manner. Positrons and electrons escaping from the COSMOS spacecraft following production by the intense gamma-radiation are stored temporarily in the Earth's magnetic field and unambiguous signal due to their characteristic annihilation into gamma-rays at 511 kev. Details of these observations and their implications are discussed.
N89-28479# Lockheed Missiles and Space Co., Palo Alto, CA.
The tools for dynamic modeling of the energetic populations in the outer radiation belts are being developed to better understand the extreme variations of particle flux in response to magnetospheric and solar activity. The study utilizes the SCATHA SC3 high-energy electron data for energies from 200 keV to 2 MeV, with fine pitch-angle measurements over the L-shell range of 5.3 to 7 for quiet and moderate geomagnetic periods in April 1979 and June 1980. A solution of the simultaneous bimodal (radial and pitch-angle) diffusion equation for the radiation belts was developed with special regard for the requirements of satellite radiation belt data analysis. The solution was used to test the bimodal theory of outer-electron-belt diffusion by confronting it with satellite data. The data representation requires and provides diffusion parameters that are in agreement with all previous experimental and theoretical determinations of such diffusion coefficients. Such a representation satisfies the basic requirements towards the dynamic modeling of the outer electron radiation belt for L is less than 7 at quiet and moderate geomagnetic conditions. The presentation was also shown to be unique when projected off of the satellite trajectory in (L,t)-space. For L about 7 the representation has difficulties with butterfly distributions that may signity energetic electron encounters with the magnetopause.
N89-28481# Naval Research Lab., Washington, DC. Gamma
Nuclear radiation from the reactor powered satellite COSMOS 1579 was monitored by the gamma ray spectrometer (GRS) on NASA's Solar Maximum Mission satellite (SMM). Gamma rays from the RORSAT (Radar Ocean Reconnaissance Satellites) were detected about every 4 days as it passed within about 500 km of SMM. In addition, events attributed to positrons emitted from the outer shell of COSMOS 1579 were detected on the average of once every about 1.5 days. These positrons were detected at large distances (less than or 5000 km) from COSMOS after being stored in the earth's magnetic field for seconds or minutes. The rate of the positron detections is about a factor of two higher than observed for most of the earlier RORSAT's detected by SMM. At present, this increase is unexplained. The qualitative features of the measured gamma-ray spectrum from COSMOS 1579 are similar to those of preceding satellites; however, the spectral features are clearer. A model is presented for the origin of these features which suggests the presence of significant amounts of beryllium, sodium, potassium, molybdenum and lithium and/or hydrogen lying with tens of gm/sq cm of material. There is also spectral evidence for the presence of either iron or aluminum. Based on this model, a conservative lower limit was obtained to the thermal power of the reactor on COSMOS 1579. This lower limit is 30 kW.
N89-28482# Naval Research Lab., Washington, DC. Gamma and Cosmic Ray Astrophysics Branch. MONITORING SOURCES OF NUCLEAR RADIATION IN SPACE 1980-1984 OBSERVATIONS, REVISION Memorandum Report, Apr. 1980 - Jan. 1985 G. H. Share, J. D. Kurtess, and D. C. Messina (Sachs/Freeman Associates, Inc., Landover, MD.) 31 May 1989 31 p Revised (AD-A209722; NRL-MR-6468; NRL-MR-5862-Rev) Avail: NTIS HC A03/MF A01 CSCL 18/4
Details are provided of SMM's observations of the seven RORSATS (Radar Ocean Reconnaissance Satellites) launched from 1980 through 1984. Estimates are obtained of the relative power of the reactors from integral gamma ray intensities measured at distances less than 400 km. The average intensities from the seven satellites, after correcting for distance of separation, are consistent with each other to within 30 percent. In contrast, the rate of distant detections of positrons increased with time over the four year period. The rate of detections was about 0.2/day in 1980 and 0.7/day in 1984. This increasing rate is due to the decreasing atmospheric density above a few hundred km in the transition from maximum to minimum solar activity. The positron storage time in the geomagnetic field is expected to increase with decreasing density. A composite gamma ray spectrum created from a summation of close-approach sightings of the seven RORSATS are presented. It is not possible to obtain a unique interpretation of this spectrum. One relatively simple model of the gamma ray spectrum emitted from the RORSATS which fits the
N89-28480# Naval Research Lab., Washington, DC. Gamma and Cosmic Ray Astrophysics Branch. DETECTION OF ARTIFICIAL SOURCES OF NUCLEAR RADIATION IN SPACE, REVISION Memorandum Report, Feb. 1980 - May 1981 G. H. Share, J. D. Kurtess, K. W. Marlow, J. A. Eisele, E. L. Chupp, and I. B. Strong (Los Alamos National Lab., NM.) May 1989 36 p Revised (AD-A209720; NRL-MR-6466; NRL-MR-4596-Rev) Avail: NTIS HC A03/MF A01 CSCL 18/4
The gamma-ray experiment on board NASA's Solar Maximum Mission Satellite (SMM) has detected nuclear radiation emitted from the reactor on COSMOS 1176. Direct observations of gamma-rays and possibly neutrons from this reactor were made
p 14-32 (For primary document see N89-28454 22-90) Avail: NTIS HCA08/MF A01 CSCL 03B
data reasonably well includes the following components: a fission continuum from U-235 and neutron capture lines from molybdenum embedded within tens of g/sq cm of material; two unresolved lines near 500 keV attributed to a line at 511 keV from positron-annihilation and to a line near 477 keV from boron.
N89-28458*# Naval Research Lab., Washington, DC. Center
(For primary document see N89-28454 22-90) Avail: NTIS HC A08/MF A01 CSCL 03B
N89-28483# Naval Research Lab., Washington, DC. Gamma and Cosmic Ray Astrophysics Branch. MONITORING SOURCES OF NUCLEAR RADIATION IN SPACE 1985-1987 OBSERVATIONS, REVISION G. H. Share, J. D. Kurtess, and D. C. Messina (Sachs/Freeman Associates, Inc., Landover, MD.) 31 May 1989 23 p Revised (AD-A209723; NRL-MR-6469; NRL-MR-6297-Rev) Avail: NTIS HC A03/MF A01 CSCL 18/4
The gamma-ray spectrometer (GRS) on NASA's Solar Maximum Mission satellite (SMM) has been monitoring Soviet nuclear reactors in space since 1980 when it detected radiation from COSMOS 1176. Direct observations of gamma radiation were made within about 500 km when the RORSATS (Radar Ocean Reconnaissance Satellites) were not occulted by a significant amount of material in SMM. Indirect observations were also made up to distances in excess of a few thousand kilometers. These observations were made when positrons and electrons produced in the outer layers of the reactor powered spacecraft reached SMM after being stored in the Earth's magnetic field. Details are provided of SMM's observations of the four RORSATS launched in 1985 and 1986, and are compared with measurements made of the seven RORSATS detected from 1980 to 1984. The average intensities from all the eleven reactor-powered satellites are consistent with each other, after correcting for distance of separation. The observed increase in the rate of distant detections of positrons from 1980 to 1984 is due to the decreasing atmospheric density above a few hundred km in the transition from maximum to minimum solar activity. The rate did not change significantly between 1984 and 1986.
N89-28459*# Jet Propulsion Lab., California Inst. of Tech., Pasadena. A NEW PROTON FLUENCE MODEL FOR E GREATER THAN 10 MeV Joan Feynman, T. P. Armstrong, L. Dao-Gibner, and S. Silverman (Boston Coll., Chestnut Hill, MA.) In its Interplanetary Particle Environment. Proceedings of a Conference 15 Apr. 1988 p 58-71 (For primary document see N89-28454 22-90) (Grant NSF ATM-83-05537) Avail: NTIS HC A08/MF A01 CSCL 03B
N89-28466*# California Inst. of Tech., Pasadena. ELEMENTAL COMPOSITION AND ENERGY SPECTRA OF GALACTIC COSMIC RAYS R. A. Mewaldt In Jet Propulsion Lab., California Inst. of Tech., Interplanetary Particle Environment. Proceedings of a Conference 15 Apr. 1988 p 121-132 (For primary document see N89-28454 22-90) (Grants NGR-05-002-160; NAG5-722) Avail: NTIS HC A08/MF A01 CSCL 03B
N89-28467*# California Inst. of Tech., Pasadena. THE ANOMALOUS COSMIC-RAY COMPONENT A. C. Cummings and E. C. Stone In Jet Propulsion Lab., California Inst. of Tech., Interplanetary Particle Environment. Proceedings of a Conference 15 Apr. 1988 p 133-134 (For primary document see N89-28454 22-90) (Contract NAS7-918; NGR-05-002-160) Avail: NTIS HC A08/MF A01 CSCL 03B
N89-28484# Utah Univ., Salt Lake City. Dept. of Physics. STUDIES OF THE COSMIC RAY PENUMBRA Final Report, 9 Sep. 1980 - 30 Sep. 1985 David J. Cooke 11 Aug. 1988 (Contract F19628-81-K-0020) (AD-A210109; AFGL-TR-88-0203) Avail: NTIS HC A06/MF A01 CSCL 03/2
The penumbra is the term used to refer to the interval of space which lies, for any given particle rigidity, between the solid angle zone within which all such particles have free access, and the region within which particle access is completely forbidden. The term is also used to refer, in a specific direction, to the rigidity interval between the lowest rigidity for which any particle may enter in the given direction, and the rigidity below which particle access is completely forbidden in the same direction. Typically the penumbra consists of a mixture of allowed and forbidden trajectories. This question of access of charged primary cosmic rays to points within the magnetic field of a plant is of great interest in numbers of areas of physics. It is very difficult, however, to map the allowed and forbidden regions of access, because of the time-consuming nature of the calculations involved. The present research has involved a systematic study of the nature of the characteristic zones of access in order to produce techniques by which information about the cosmic ray penumbra may efficiently be derived. The work has then focused on the mapping and study of the phenomenology of the penumbra.
N89-28468*# Chicago Univ., IL.
N89-28456*# Jet Propulsion Lab., California Inst. of Tech.,
N89-28469*# Delaware Univ., Newark. TIME VARIATION OF GALACTIC COSMIC RAYS Paul Evenson In Jet Propulsion Lab., California Inst. of Tech., Interplanetary Particle Environment. Proceedings of a Conference 15 Apr. 1988 p 149-161 (For primary document see N89-28454 22-90) (Grants NAG5-374; NSF ATM-86-03192) Avail: NTIS HC A08/MF A01 CSCL 033
N89-28470*# Arizona Univ., Tucson.
No abstracts in this category.