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SunRISE: Sun Radio Interferometer Space Experiment: Revealing How Energetic Particles Are Accelerated and Released Into Interplanetary Space
No abstract provided
Ecology and thermal inactivation of microbes in and on interplanetary space vehicle components Fourth quarterly progress report, Jan. 1 - Mar. 31, 1966
Dry heat inactivation of Bacillus globigii spores encapsulated in Lucite to simulate interplanetary spacecraft conditions
Nonlinear Alfven Waves in Interplanetary Space
The properties of Alfven waves detected in both high-speed and slow-speed streams as detected by Ulysses will be reviewed.
The first taste of a hot channel in interplanetary space
A hot channel (HC) is a high temperature (∼10 MK) structure in the inner corona first revealed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. Eruptions of HCs are often associated with flares and coronal mass ejections (CMEs). Results of previous studies have suggested that an HC is a good proxy for a magnetic flux rope (MFR) in the inner corona as well as another well known MFR candidate, the prominence-cavity structure, which has a normal coronal temperature (∼1–2 MK). In this paper, we report a high temperature structure (HTS, ∼1.5 MK) contained in an interplanetary CME induced by an HC eruption. According to the observations of bidirectional electrons, high temperature and density, strong magnetic field, and its association with the shock, sheath, and plasma pile-up region, we suggest that the HTS is the interplanetary counterpart of the HC. The scale of the measured HTS is around 14 R {sub ⊙}, and it maintained a much higher temperature than the background solar wind even at 1 AU. It is significantly different from the typical magnetic clouds, which usually have a much lower temperature. Our study suggests that the existence of a corotating interaction region ahead of the HC formed a magnetic container to inhibit expansion of the HC and cool it down to a low temperature.
The electromagnetic structure of interplanetary space
A method to calculate the three-dimensional structure of the interplanetary magnetic field is presented. The integrations are based on magnetograph recordings of longitudinal magnetic fields in the solar photosphere. The program by Altschuler and Newkirk is used to calculate the radial component of the magnetic field on the source surface, situated at r = 2.6r. This determines the inner boundary conditions for the integration outwards of the interplanetary field equations by means of the method that is described. Computer-drawn plots of the interplanetary field lines out to the earth's orbit are presented for the periods around the total solar eclipses of November 12, 1966, and March 7, 1970. During the former period the interplanetary field exhibited a clean, dipole-type structure, while during the latter period the field was more complicated and had four sectors in the equatorial plane. A movie was presented, showing how the interplanetary field structure rotates as seen by a magnetometer in the sun's equatorial plane.
Correlation of interplanetary-space B sub z field fluctuations and trapped-particle redistribution.
Observations of interplanetary magnetic field fluctuations in correlation with trapped particle fluctuations are discussed. From observations of particle-redistribution effects, properties of the magnetospheric electric field are derived. The obtained results suggest that the interplanetary B(sub z) field fluctuations might represent a strong driving source for particle diffusion.
Propagation of solar disturbances in interplanetary space
Time-dependent solutions of a one-fluid model of the interplanetary medium are investigated. This set of unsteady hydrodynamic equations has been written in conservation form in order to apply the Lax-Wendroff method for the solution of this problem. The initial condition is specified by a pulse at 1 solar radius. The equilibrium condition is chosen to be the steady solution of a quiet solar wind. The specified solar disturbances in this calculation are allowed to be both sub- and supersonic by the present theoretical formulation. The results are presented in terms of density, velocity, and temperature profiles of the interplanetary gas flow at heliocentric distances up to about 10 AU at any particular time. The trajectories of disturbances for various initial pulses are shown. Some 1972 solar-flare observational data are compared with these theoretical calculations. From these calculations, the effects on the interplanetary environment, due to the propagation of solar disturbances, can be determined.
Selection of optical sightings for position determination in interplanetary space.
Selection of optical sightings for position determination by self-contained navigation system for interplanetary spacecraft
Anisotropy of shock-accelerated ion distributions in interplanetary space
The discrepancy between theory and observation is discussed with regard to the ability of interplanetary shock waves to accelerate a small percentage of the thermal ion population. The major point of departure rests with the spatial dependence of the energetic particle intensity and anisotropy in the region upstream of interplanetary shocks. It is argued that the discrepancy is due to the presence of solar flare particles forming an additional seed population which alters the upstream boundary condition of the energetic population. The resulting anisotropy of the energetic particle distribution several scale lengths upstream of the shock is proportional to the ratio of the streaming of the shock-accelerated population to the density of the solar flare population. This theory is then compared with the results of observed upstream anisotropy and measured particle intensities and anisotropies.
BioSentinel/Mars: Interplanetary Space Radiation Biosensor Experiment in Martian Transit on Mars 2020
Despite significant progress understanding biological radiation effects via terrestrial studies, no terrestrial source duplicates space’s unique radiation environment. Furthermore, no biological experiments have been conducted beyond low Earth orbit since Apollo. Understanding space’s fundamental biological effects requires overcoming these limitations. The BioSentinel 4U payload, under development for flight aboard Exploration Mission-1, measures biological responses to deep space radiation. Traveling to more than 1AU from Earth, BioSentinel/EM-1 will record DNA double-strand breaks (DSBs) repaired using a pathway common to humans and BioSentinel’s bioengineered yeast model organism, responding to as few as one biologically repaired DSB. The BioSentinel/Mars 4U instrument (6-8kg; 5-8W; 0.2-1MB/week) would include eighteen 16-well biosensor fluidic cards, activated biweekly during Mars 2020’s cruise phase, to provide a dose-dependent rate of DSB/repair. The instrument, which includes solid-state sensors for total ionizing dose and linear-energy-transfer spectra, addresses MEPAG SKG-B3 by simultaneously measuring both spectra and biological effects of space radiation. Biological measurements are rendered reliable by independent replicate experiments. The spatio-temporal uniformity of interplanetary galactic cosmic radiation makes BioSentinel/EM1 and BioSentinel/Mars approximate replicates, except for any major differences in solar particle events. Results will be compared to Earth and ISS controls to characterize the radiation/reduced-gravity parameter space by its biological impact.
Low-energy protons: Gradients in interplanetary space and distribution in the solar corona
First and second order anisotropy measurements are proposed as a tool for studying the coronal source function and interplanetary propagation of low energy protons. Optimum orbit and attitude requirements are suggested for a three telescope system. Some limitations with regard to the lower energy limit for a feasible set-up are discussed.
Possible acceleration of charged particles through the reconnection of magnetic field lines in interplanetary space
Prominent intensity spikes in the flux of protons and alphas with less than 0.5 MeV per charge were observed in the region several hours behind an interplanetary shock front. The small spatial scale of these events and the high anisotropy of the particle flux suggest local acceleration. The spectra of the particles, which are cut off at equal energy per charge, suggest acceleration through an electric field. The possibility is examined that these events have their origin in active magnetic neutral sheets in the shocked solar wind.
ANALYTIC SOLUTION OF THE EQUATIONS OF MOTION OF AN INTERPLANETARY SPACE VEHICLE IN THE MIDCOURSE PHASE OF ITS FLIGHT
Two methods for solving sixth-order linear system constituting the motion equations for midcourse phase of a ballistic interplanetary flight
Possible acceleration of charged particles through the reconnection of magnetic field lines in interplanetary space
Prominent intensity spikes in the flux of protons and alphas with less than 0.5 MeV per charge have been observed in the region several hours behind an interplanetary shock front. The small spatial scale of these events and the high anisotropy of the particle flux suggest local acceleration. The spectra of the particles, which are cut off at equal energy per charge, suggest acceleration through an electric field. The possibility that these events have their origin in active magnetic neutral sheets in the shocked solar wind is examined.
Mass ejections from the solar corona into interplanetary space
Results obtained from analysis of Skylab coronagraph images of mass ejections from the solar corona are reviewed which demonstrate the importance of mass-ejection coronal transients to the interplanetary medium and which support the belief that magnetic forces are the primary mechanism driving mass ejections from the corona. Observations of 13 large ejection events are examined which indicate that coronal mass ejections contribute a nonnegligible fraction of the mass flux from the sun, especially toward the heliographic equator near the maximum of a solar activity cycle. It is shown that observed loop-shaped transients were associated with regions of increased magnetic field and with separations of unipolar field regions, that the forces driving the transients outward acted to great heights long after the onsets of the events, and that the behavior of the ejecta was magnetically controlled. It is concluded that mass ejections from the corona contributed at least 3% of the mass flux from the sun during the Skylab era and that the most common loop-shaped ejections are magnetically driven through the corona.
Dependence of the High Latitude Middle Atmosphere Ionization on Structures in Interplanetary Space
The precipitation of high energetic electrons during and after strong geomagnetic storms into heights below 100 km in middle and subauroral latitudes is markedly modulated by the structure of the interplanetary magnetic field (IMF). Under relative quiet conditions the D-region ionization caused by high energetic particle precipitation (energies greater than 20 to 50 keV) depends on changes of the interplanetary magnetic field and also on the velocity of the solar wind. To test this assumption, the influence of the IMF-sector boundary crossings on ionospheric absorption data of high and middle latitudes by the superposed-epoch method was investigated.