225
225
Jun 27, 2010
06/10
by
Gnos, A. V
texts
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No Abstract Available
Topics: FIGHTER AIRCRAFT, INTAKE SYSTEMS, SURGES, TURBOJET ENGINES, GRAPHS (CHARTS), MASS FLOW FACTORS,...
255
255
Jun 21, 2010
06/10
by
Kashyap, R. L
texts
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Maximum likelihood identification of stochastic linear systems
Topics: APOLLO 8 FLIGHT, STAGE SEPARATION, PROPULSION SYSTEM PERFORMANCE, SATURN S-2 STAGE, FUEL TANK...
307
307
Jun 27, 2010
06/10
by
Hennings, G.; Ladanyi, D. J
texts
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No Abstract Available
Topics: COMPUTERIZED SIMULATION, REACTOR STARTUP TESTS, SHUTDOWNS, SNAP 8, DIGITAL COMPUTERS, GRAPHS...
935
935
Jun 15, 2011
06/11
by
NON
texts
eye 935
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No Abstract Available
Topics: POSTFLIGHT ANALYSIS, SURVEYOR PROJECT, SURVEYOR 3 LUNAR PROBE, DATA PROCESSING, DATA REDUCTION,...
271
271
Jul 5, 2010
07/10
by
Lubick, R. J.; Sivo, J. N.; Smith, R. W.; Valentine, H. H.; Zimmerman, A. V
texts
eye 271
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No Abstract Available
Topics: MERCURY PROJECT, REYNOLDS NUMBER, WIND TUNNEL STABILITY TESTS, GRAPHS (CHARTS), HYPERSONIC SPEED,...
974
974
Jul 6, 2010
07/10
by
Vannimwegen, R. R.; Tepper, S
texts
eye 974
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Combinations of high temperature gradients associated with strong transients in both temperature and rotational speed fields are discussed. Blade definition and results of the analysis are shown. Since the same model should later be used to define some dynamic characteristics and certain areas would require a nonlinear analysis, NASTRAN was chosen as a convenient program to manage the several alternatives.
Topics: FLARED BODIES, FRAGMENTATION, MATHEMATICAL MODELS, METEOROIDS, ASTRONOMICAL PHOTOMETRY, BRIGHTNESS,...
261
261
May 23, 2011
05/11
by
Oliker, Leoni
texts
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Dynamic mesh adaption on unstructured grids is a powerful tool for computing large-scale problems that require grid modifications to efficiently resolve solution features. By locally refining and coarsening the mesh to capture physical phenomena of interest, such procedures make standard computational methods more cost effective. Unfortunately, an efficient parallel implementation of these adaptive methods is rather difficult to achieve, primarily due to the load imbalance created by the...
Topics: COMPUTER PROGRAMMING, DIAGRAMS, SOFTWARE ENGINEERING, SOFTWARE DEVELOPMENT TOOLS, CONSISTENCY,...
213
213
Jun 13, 2011
06/11
by
Jones, Michael G.; Parrott, Tony L
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CONTINUING progress in materials technology provides potential for improved acoustic liners for attenuating broadband fan noise emissions from aircraft engine nacelles. Conventional liners (local-reacting perforate-over-honeycomb structures) provide significant narrow-band attenuation, but limited attenuation over wide bandwidths. Two approaches for increasing attenuation bandwidth are to (1) replace the honeycomb structure with bulk material, or (2) cascade multiple layers of...
Topics: ALGORITHMS, GRAPHS (CHARTS), FORECASTING, PLANNING, DATA SYSTEMS, DOMAINS, ECOSYSTEMS
134
134
Jul 11, 2010
07/10
by
Wolf, M.; Crossman, L. D
texts
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Si reduction, purification and sheet generation work has been concentrated on gaining information about a reduction process combined with purification (higher purity arc furnace with gas blowing and gradient freezing), transport process with purification and polycrystal sheet growth potential (SiF2), plastic deformation for sheet generation, and float zone sheet recrystallization.
Topics: DISTRIBUTION MOMENTS, RADIAL DISTRIBUTION, RANDOM VARIABLES, RAYLEIGH DISTRIBUTION, GRAPHS...
255
255
Jun 21, 2010
06/10
by
Johnson, B. V
texts
eye 255
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No Abstract Available
Topics: HYPERVELOCITY PROJECTILES, TEST FACILITIES, LIGHT GAS GUNS, MICROMETEOROIDS, SIMULATORS,...
1,409
1.4K
Jul 11, 2010
07/10
by
NON
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Active university research projects for Fiscal Year 1975 are reported by state, and foreign country. Cross indexes by: (1) grant/contract number; (2) field of science and engineering; (3) technical officer location; and (4) RTOP are included.
Topics: COMPUTER GRAPHICS, COMPUTER TECHNIQUES, MANAGEMENT, MANAGEMENT INFORMATION SYSTEMS, DATA BASES,...
157
157
Jul 21, 2010
07/10
by
Draine, B. T
texts
eye 157
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Dust formation around cool giant and supergiant stars is examined in terms of grain formulation. Optical properties of small clusters, molecular physics of cluster nucleation and growth, circumstellar mass flows, and their application to alpha Ori are discussed.
Topics: COMPUTERIZED SIMULATION, LIQUID OXYGEN, SPACE SHUTTLE MAIN ENGINE, TURBINE PUMPS, COOLANTS, GRAPHS...
A 20-cm high, 18-cm wide, and 30-cm long (8x7x12 inch) box weighing about 7 kg (15 lbs) and consuming about 7 watts of power was carried on the OSS-1 pallet to monitor the mass build-up or accretion of condensible, volatile materials on surfaces in the shuttle bay during all phases of ascent, on-orbit, and descent. Passively thermally controlled, the box holds two witness samples and four actively temperature controlled quartz crystal microbalances (TQCM) whose temperature can vary from -60 C...
Topics: NASA Technical Reports Server (NTRS), BAYS (STRUCTURAL UNITS), MICROBALANCES, MONITORS, OSS-1...
Information is given in the form of outlines, graphs, tables and charts. Topics include system identification, Bayesian statistical decision theory, Maximum Likelihood Estimation, identification methods, structural mode identification using a stochastic realization algorithm, and identification results regarding membrane simulations and X-29 flutter flight test data.
Topics: NASA Technical Reports Server (NTRS), BAYES THEOREM, FLUTTER, MAXIMUM LIKELIHOOD ESTIMATES,...
Because of the great environmental significance of ozone and to support continuing research at the Antarctic and other Southern Hemisphere stations, the development of the 1990 ozone hole was monitored using data from the Nimbus-7 Total Ozone Mapping Spectrometer (TOMS) instrument, produced in near-real-time. This Atlas provides a complete set of daily polar orthographic projections of the TOMS total ozone measurements over the Southern Hemisphere for the period 1 Aug. through 31 Dec. 1990. The...
Topics: NASA Technical Reports Server (NTRS), ANTARCTIC REGIONS, CALIBRATING, NIMBUS 7 SATELLITE, OZONE,...
A recalibration of the Space Shuttle Vehicle Ascent Air Data System probe was conducted in the Arnold Engineering Development Center (AEDC) transonic wind tunnel. The purpose was to improve on the accuracy of the previous calibration in order to reduce the existing uncertainties in the system. A probe tip attached to a 0.07-scale External Tank Forebody model was tested at angles of attack of -8 to +4 degrees and sideslip angles of -4 to +4 degrees. High precision instrumentation was used to...
Topics: NASA Technical Reports Server (NTRS), AIR DATA SYSTEMS, ASCENT, CALIBRATING, EXTERNAL TANKS,...
One of the current debates raging in the world of gamma-ray burst physics is whether the sources of these enigmatic bursts arise from a single or from multiple distributions. Several authors contend that the histograms of GRB observables imply the latter. The two most-likely candidate components are galactic and cosmological. For example, some researchers claim that a dip in the V/V max distribution is a result of such a two-component source distribution. Others have used a parameter called the...
Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, COSMOLOGY, GAMMA RAY BURSTS, GAMMA RAY...
This effort was conducted to obtain additional test data/configurations required to better understand the effects of tab length and width on jet mixing enhancement for a rectangular nozzle. The configurations tested were a six-tab configuration defined by NASA, a full-height tab configuration, and two-tab configurations with selected tab lengths and widths. Additional test data were also required for all candidate configurations to better interpret the data. Test data from this effect are...
Topics: NASA Technical Reports Server (NTRS), FLUID JETS, JET MIXING FLOW, NOZZLE DESIGN, NOZZLE FLOW,...
Telstar 401 was launched December 15, 1993. It has two 58 cell 50 AH Nickel Hydrogen batteries of the Comsat design. Reconditioning has traditionally been used as a means of maintaining the performance of normal cells and batteries. This paper describes a situation in which reconditioning was used to improve the performance of nickel-hydrogen batteries in Telstar 40. Reconditioning is carried out with relay selected resistors across the entire battery for rates of approximately C/50 and C/100....
Topics: NASA Technical Reports Server (NTRS), NICKEL HYDROGEN BATTERIES, PERFORMANCE TESTS, RELIABILITY...
The development of large-scale, composite software in a geographically distributed environment is an evolutionary process. Often, in such evolving systems, striving for consistency is complicated by many factors, because development participants have various locations, skills, responsibilities, roles, opinions, languages, terminology and different degrees of abstraction they employ. This naturally leads to many partial specifications or viewpoints. These multiple views on the system being...
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMMING, SOFTWARE ENGINEERING, SOFTWARE...
Atmospheric variability over time scales greater than one month is conceptually simplified and readily recognized from vertical cross-sections of zonal-monthly mean data. The reduction to two dimensions, latitude and height, explicitly eliminates all zonal waves but implicity retains their effects on the thermal-pressure fields and the dynamically related zonal wind fields. This atlas contains 96 examples, spanning all latitudes in both the northern and southern hemispheres and two decades in...
Topics: NASA Technical Reports Server (NTRS), ANNUAL VARIATIONS, ATMOSPHERIC TEMPERATURE, GEOSTROPHIC WIND,...
Cryogenic space engines require a cooling process to condition engine hardware to operating temperature before start. This can be accomplished most efficiently by burning propellants that would otherwise be dumped overboard after cooling the engine. The resultant low thrust operating modes are called Tank Head Idle and Pumped Idle. During February 1984, Pratt & Whitney conducted a series of tests demonstrating operation of the RL10 rocket engines at low thrust levels using a previously...
Topics: NASA Technical Reports Server (NTRS), BREADBOARD MODELS, CRYOGENIC ROCKET PROPELLANTS, ENGINE...
The numerical results of statistical analysis of the test data of Space Shuttle Main Engine high pressure fuel turbopump second-stage turbine blades, including some with cracks are presented. Several statistical methods use the test data to determine the application of differences in frequency variations between the uncracked and cracked blades.
Topics: NASA Technical Reports Server (NTRS), SPACE SHUTTLE MAIN ENGINE, STATISTICAL ANALYSIS, TURBINE...
Low-g accelerometers were used by NASA on a variety of flights for over 12 years. These flights have included aircraft parabolas, suborbital trajectories, and orbital missions. This large quantity of data has undergone only limited in-depth analyses. Examples of data in many forms and results of analyses such as power spectral densities and shock spectra are given for a wide variety of missions. Accelerometers used to acquire the data are also identified.
Topics: NASA Technical Reports Server (NTRS), ACCELEROMETERS, CALIBRATING, MICROGRAVITY, SPACE SHUTTLE...
The problem of allocating nodes of a program graph to processors in a parallel processing architecture is considered. The algorithm is based on critical path analysis, some allocation heuristics, and the execution granularity of nodes in a program graph. These factors, and the structure of interprocessor communication network, influence the allocation. To achieve realistic estimations of the executive durations of allocations, the algorithm considers the fact that nodes in a program graph have...
Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, ALLOCATIONS, COMMUNICATION NETWORKS, PARALLEL...
The trajectory plots for IMP 7 (Explorer 47) are contained. For each orbit the trajectory is shown in five panels on two pages; each panel is a different representation or projection. The trajectory parameters were obtained from the multi-coordinate ephemeris (MCE) tapes supplied to IMP experimenters by the IMP project. The plots on the right hand pages use a geocentric, solar-ecliptic coordinate system. Distances are in units of earth radii. The plots on the left hand pages use geocentric,...
Topics: NASA Technical Reports Server (NTRS), EPHEMERIS TIME, EXPLORER 47 SATELLITE, SPACECRAFT...
This is the eighth in a series of volumes pertaining to the Polar Region Outer Magnetosphere International Study (PROMIS). This volume contains 24 hour stack plots of 1-minute average, H and D component, ground magnetograms for the period March 10 through June 16, 1986. Nine midlatitude ground stations were selected from the UCLA magnetogram data base that was constructed from all available digitized magnetogram stations. The primary purpose of this publication is to allow users to define...
Topics: NASA Technical Reports Server (NTRS), EARTH MAGNETOSPHERE, MAGNETIC SIGNATURES, MAGNETIC STORMS,...
This project compared the forces and moments produced by straight and 15 degree vectored nozzles. Using the six component thrust stand in the engines laboratory at California Polytechnic State University, several trials were performed. This data was then reduced using first a computer program and then later an electronic spreadsheet. This reduced data was graphed and compared. As a result of these comparisons some unexpected forces were discovered. Several more tests were run including a zero...
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, ENGINE TESTS, EXHAUST NOZZLES, STATISTICAL...
The modeling and design of a fault-tolerant multiprocessor system is addressed. Of interest is the behavior of the system during recovery and restoration after a fault has occurred. The multiprocessor systems are based on the Algorithm to Architecture Mapping Model (ATAMM) and the fault considered is the death of a processor. The developed model is useful in the determination of performance bounds of the system during recovery and restoration. The performance bounds include time to recover from...
Topics: NASA Technical Reports Server (NTRS), FAULT TOLERANCE, MULTIPROCESSING (COMPUTERS), PERFORMANCE...
The Tracking and Data System (TDS) Support for the Mariner Mars 1971 Mission final report contains the deep space tracking and data acquisition activities in support of orbital operations. During this period a major NASA objective was accomplished: completion of the 180th revolution and 90th day of data gathering with the spacecraft about the planet Mars. Included are presentations of the TDS flight support pass chronology data for each of the Deep Space Stations used, and performance...
Topics: NASA Technical Reports Server (NTRS), DATA ACQUISITION, MARINER SPACE PROBES, MARS 71 PROJECT,...
The results of tests on processing the overexposed film on Skylab 4 are reported. The results of tests on type 2443 film exposed without a Wratten 12 filter are also included.
Topics: NASA Technical Reports Server (NTRS), IMAGING TECHNIQUES, PHOTOGRAPHIC PROCESSING, SKYLAB 4, GRAPHS...
Results for a seasonally varying diurnal tide in temperature at Churchill are presented, and possible significant aliasing of longer period waves by this tide is discussed. A diurnal tide whose amplitude and phase are coherent throughout the year is found to have little effect on periodic amplitudes other than the long-term mean, because most rocketsonde observations are taken near the same local time each day. Errors in periodic components arising from lack of solar radiation corrections are...
Topics: NASA Technical Reports Server (NTRS), ANNUAL VARIATIONS, ATMOSPHERIC TEMPERATURE, DIURNAL...
Aerodynamic force data are presented in tables and graphs for the NASA Langley V/STOL Transition Research Wind Tunnel tests on a 0.04 scale model of the 747 with a 0.0405 scale Orbiter space shuttle. The investigation included the effects of flap setting, stabilizer angle, elevator angle, ground proximity, and Orbiter tailcone fairing. Data were obtained in the pitch plane only. The test was run at M = 0.15, with a dynamic pressure of 35 psf. Six static pressures were measured on each side of...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CHARACTERISTICS, BOEING 747 AIRCRAFT, SCALE...
A two-dimensional, linear-elastic, finite element analysis of selected graphite/polyimide rail shear test specimens was made to determine the mechanical loading and the effect of heating the specimen to a uniform temperature. The presence of specimen free edges and their influence on the accuracy of the rail shear test is discussed. Parameters include the length-to-width ratio of the specimen and the ply layup for symmetric, balanced laminates. Results presented include shear and normal stress...
Topics: NASA Technical Reports Server (NTRS), COMPOSITE MATERIALS, FINITE ELEMENT METHOD, GRAPHITE, LOAD...
The results of an experimental investigation that was concerned with the quantitative determination of the capabilities of combustion processes associated with coaxial injectors to amplify and sustain combustor oscillations was described. The driving provided by the combustion process was determined by employing the modified standing-wave method utilizing coaxial injectors and air-acetylene mixtures. Analyses of the measured data indicate that the investigated injectors are capable of...
Topics: NASA Technical Reports Server (NTRS), COMBUSTION STABILITY, FUEL INJECTION, GASEOUS ROCKET...
The activities carried out by the Smithsonian Astrophysical Observatory (SAO) for the National Aeronautics and Space Administration (NASA) during the period 1 July to 31 December 1978 are described. All four SAO laser sites were in routine operation during the reporting period; they obtained a 6-month total of 182,529 range observations on 3610 passes.
Topics: NASA Technical Reports Server (NTRS), DATA ACQUISITION, LASER RANGER/TRACKER, NASA PROGRAMS,...
Satellites provide an excellent platform from which to observe crops on the scale and frequency required to provide accurate crop production estimates on a worldwide basis. Multispectral imaging sensors aboard these platforms are capable of providing data from which to derive acreage and production estimates. The issue of sensor swath width was examined. The quantitative trade trade necessary to resolve the combined issue of sensor swath width, number of platforms, and their orbits was...
Topics: NASA Technical Reports Server (NTRS), AGRICULTURE, CROP INVENTORIES, MULTISPECTRAL BAND SCANNERS,...
The long term evolution of an accreting carbon white dwarf was studied from the onset of accretion to the ignition of helium. The variations in the details of the helium shell flash examined with respect to variations in mass accretion rate. For intermediate rates the helium flash is potentially explosive whereas for high rates the shell flash is relatively weak. The results are discussed in the context of the long term evolution of novae.
Topics: NASA Technical Reports Server (NTRS), HELIUM, NOVAE, STELLAR EVOLUTION, STELLAR MASS ACCRETION,...
Wind tunnel tests were conducted to obtain aerodynamic force data for Mach numbers from 0.60 to 1.20. Data were obtained for an alpha range of -10 deg to +10 deg (beta = 0 deg beta = 5 deg) and beta range of -10 deg to +10 deg (alpha = 0 deg). Longitudinal and lateral-directional stability and control data were obtained for tank alone, tank plus SRB's, tank plus Orbiter, and mated configuration of tank + Orbiter + SRB's. Also, single-component rudder hinge moment data were obtained at rudder...
Topics: NASA Technical Reports Server (NTRS), SPACE SHUTTLES, SPACECRAFT MODELS, TRANSONIC WIND TUNNELS,...
Four sets of graphic reports--one for each of the metering and spacing scenarios--are presented. The complete data file from which the reports were generated is also given. The data was used to validate the detail task of both the pilot and copilot for four metering and spacing scenarios. The output presents two measures of demand workload and a report showing task length and task interaction.
Topics: NASA Technical Reports Server (NTRS), AIR TRAFFIC CONTROL, GENERAL AVIATION AIRCRAFT, MAN MACHINE...
A summary is given of the noise suppression tests conducted for the STOL aircraft. The tests were made using a large scale mixer nozzle and externally blown flap model. Data were obtained over a range of nozzle exhaust velocities (172 to 284 m/sec) and flap angles. Comparisons were made between the results of the mixer nozzle and those obtained with a standard single convergent nozzle. The resulting conclusions show that a reduction in noise level did occur using the mixer nozzle system.
Topics: NASA Technical Reports Server (NTRS), FLAPS (CONTROL SURFACES), NOISE REDUCTION, NOZZLE EFFICIENCY,...
No abstract available
Topics: NASA Technical Reports Server (NTRS), HISTOGRAMS, ERRORS, SAMPLING, KURTOSIS, SKEWNESS, NORMAL...
Ultrasonography is increasingly used to quickly measure optic nerve sheath diameter (ONSD) when increased intracranial pressure (ICP) is suspected. NASA Space and Clinical Operations Division has been using ground and on-orbit ultrasound since 2009 as a proxy for ICP in non-acute monitoring for space medicine purposes. In the terrestrial emergency room population, an ONSD greater than 0.59 cm is considered highly predictive of elevated intracranial pressure. However, this cut-off limit is not...
Topics: NASA Technical Reports Server (NTRS), INTRACRANIAL PRESSURE, ULTRASONICS, ASTRONAUTS, SPACE FLIGHT,...
Fabric Images Inc., specializing in the printing and manufacturing of fabric tension architecture for the retail, museum, and exhibit/tradeshow communities, designed software to translate 2-D graphics for 3-D surfaces prior to print production. Fabric Images' fabric-flattening design process models a 3-D surface based on computer-aided design (CAD) specifications. The surface geometry of the model is used to form a 2-D template, similar to a flattening process developed by NASA's Glenn Research...
Topics: NASA Technical Reports Server (NTRS), DESIGN ANALYSIS, GRAPHS (CHARTS), COMPUTER AIDED DESIGN,...
Handbook describes design processes, presents design considerations and techniques, gives tutorial material on implementation and methodology, shows design aids, illustrates use of design aids and application samples, and identifies general practices to be adhered to or avoided.
Topics: NASA Technical Reports Server (NTRS), GRAPHS (CHARTS), HANDBOOKS, MANUALS, PROVING, REDUNDANCY,...
A cost analysis of the major items of direct operating costs in an intraurban aircraft transportation system are presented. The results are given in the form of tables and graphs.
Topics: NASA Technical Reports Server (NTRS), AIR TRANSPORTATION, COST ANALYSIS, GRAPHS (CHARTS), TABLES...
Model information and data obtained from wind tunnel tests performed on a 0.006 scale model of the Rockwell International space shuttle orbiter and external tank in the 18 inch Variable Density Hypersonic Wind Tunnel (VDHT) at NASA Langley Research Center are presented. Tests were performed at a Mach number of 8.0 over a Reynolds Number range from 0.1 to 10.0 million per foot at 0 deg and -5 deg angle of attack and 0 deg sideslip angle. Transition heating rates were determined using thin skin...
Topics: NASA Technical Reports Server (NTRS), EXTERNAL TANKS, SPACE SHUTTLE ORBITERS, SPACECRAFT MODELS,...
There are no author-identified significant results in this report.
Topics: NASA Technical Reports Server (NTRS), AERONAUTICS, GRAPHS (CHARTS), HYDROLOGY, LAKES, SAN FRANCISCO...
Millimeter-wave frequency converters on a diode with a Schottky barrier were analyzed. The analysis includes investigation of the effect of the variable capacitance of the diode's elements on the frequency converters. Specifically, the transmission, impedance, and noise characteristics of the frequency converters were examined.
Topics: NASA Technical Reports Server (NTRS), FREQUENCY CONVERTERS, MILLIMETER WAVES, SCHOTTKY DIODES,...
Metal ions including Na-40(+), Mg-24(+), Si-28(+), K-39(+), Ca-40(+), Sc-45(+), Cr-52(+), Fe-56(+), and Ni-58(+) were detected in the upper atmosphere during the beta Taurids meteor shower. Abundances of these ions relative to Si(+) show agreement in most instances with chondrites. A notable exception is 45(+), which is Sc(+), is 100 times more abundant than neutral scandium found in chondrites.
Topics: NASA Technical Reports Server (NTRS), COMETS, MASS SPECTROMETERS, METAL IONS, TAURID METEOROIDS,...
