Induced charging of shuttle orbiter by high electron-beam currents

Emission of high-current electron beams that was proposed for some Spacelab payloads required substantial return currents to the orbiter skin in order to neutralize the beam charge. Since the outer skin of the vehicle was covered with approximately 1200 sq m of thermal insulation which has the dielectric quality of air and an electrical conductivity that was estimated by NASA at 10 to the -9 power to 10 to the -10 power mhos/m, considerable transient charging and local potential differences were anticipated across the insulation. The theory for induced charging of spacecraft due to operation of electron guns was only developed for spherical metal vehicles and constant emission currents, which were not directly applicable to the orbiter situation. Field-aligned collection of electron return current from the ambient ionosphere at orbiter altitudes provides up to approximately 150 mA on the conducting surfaces and approximately 2.4 A on the dielectric thermal insulation. Local ionization of the neutral atmosphere by energetic electron bombardment or electrical breakdown may provide somewhat more return current

Continued convection and the initial recovery of Dst

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94856/1/grl16086.pd

Yet another caveat to using the Dessler‐Parker‐Sckopke relation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95475/1/jgra16950.pd

Ring current simulations of the 90 intense storms during solar cycle 23

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94717/1/jgra19539.pd

Magnetospheric convection electric field dynamics and stormtime particle energization: Case study of the magnetic storm of 4 May 1998

It is shown that narrow channels of high electric field are an effective mechanism for injecting plasma into the inner magnetosphere. Analytical expressions for the electric field cannot produce these channels of intense plasma flow, and thus, result in less entry and adiabatic energization of the plasma sheet into near-Earth space. For the ions, omission of these channels leads to an underprediction of the strength of the stormtime ring current and therefore, an underestimation of the geoeffectiveness of the storm event. For the electrons, omission of these channels leads to the inability to create a seed population of 10-100 keV electrons deep in the inner magnetosphere. These electrons can eventually be accelerated into MeV radiation belt particles. To examine this, the 1-7 May 1998 magnetic storm is studied with a plasma transport model by using three different convection electric field models: Volland-Stern, Weimer, and AMIE. It is found that the AMIE model can produce particle fluxes that are several orders of magnitude higher in the <i>L</i> = 2 – 4 range of the inner magnetosphere, even for a similar total cross-tail potential difference. <br><br><b>Key words.</b> Space plasma physics (charged particle motion and acceleration) – Magnetospheric physics (electric fields, storms and substorms

Editorial: Multiyear Analysis of JGR Space Physics Reviewing Statistics

The editorial decision process for the Journal of Geophysical Research Space Physics is assisted by over 1,000 scientists every year, providing over 3,000 reviews per year. These statistics are presented for the years 2013 through 2018, showing some fluctuations but, overall, consistency in the response of the space physics research community to requests to serve as manuscript reviewers. Over half of these reviews are submitted on time, and the average time to review actually dropped as the load increased. This is greatly appreciated and the community is to be commended and thanked for their willingness to help make this journal thrive and remain a premiere publication in the field.Key PointsA total of 1,366 scientists submitted 3,209 reviews on 1,054 unique manuscripts in 2018, the latest year for which numbers are fully compiledStatistics for 2018 are compared against those from the previous 5 years, revealing temporal trends in reviewing metricsWhile some fluctuations exist, the values reveal consistency in both the editorial process and reviewer compliance across the yearsPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154287/1/jgra55564.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154287/2/jgra55564_am.pd

Characterization of reflected light from the space power system

Sunlight reflected off large space structures is examined. To assure that this illumination does not exceed the irradiance tolerances of the eye, reflections from these satellites must be controlled by vehicle orientation and surface specifications. The components of various space power system vehicles to determine the reflectances which will significantly contribute to the ground illumination are evaluated. Calculations of reflected solar intensity from various satellite system elements requires description of the elements and of the geometry potential reflectance paths. Surface intensity and the conditions under which it will illuminate a portion of the Earth are also determined

Experiment definition studies for AMPS Spacelab

The electrical charging of the space shuttle orbiter is discussed in relation to the AMPS Spacelab payload along with an operations research technique for the selection of AMPS Spacelab experiments. Experiments proposed for AMPS include: hydromagnetic wave experiments; bistatic sounder of AMPS wake; and an artificial meteor gun. Experiment objectives and instrument functions are given for all experiments

Transport of photoelectrons in the nightside magnetosphere

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95682/1/jgra16120.pd

The magnetospheric banana current

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97486/1/jgra50153.pd