Space Weather Quarterly Volume 11, Issue 1, 2014

Abstract

In memoriam of Robert D. Hunsucker, an authority on radio propagation, radio sensing of the ionosphere, and the effects of AGWs on the ionosphere. Effects of solar cycle 24 activity on WAAS navigationBy Seebany Datta-Barua, Todd Walter, Gary S. Bust, and William WannerThe effects of geomagnetic activity of solar cycle 24 on WAAS navigation service. Meeting ReportA spacecraft immersed in an energetic plasma environment can experience significant charging. Typically driven by electrons with energies between a few tens of eV to ~100 keV, the charge can build up externally and, depending on surface properties, produce potential differences of near the ambient electron temperature (~100 V to 10 kV). At higher energies, electrons between 100 keV and ~10 MeV can penetrate a typical spacecraft surface and deposit charge internally on isolated conductors or in dielectrics. Again, the buildup of this charge can lead to large potential differences. Ultimately potential differences on or internal to the spacecraft can lead to arc discharges and other deleterious effects. Spacecraft charging/arcing is recognized as one of the main concerns for designing survivable spacecraft.Since about 1974 engineers and scientist who study charging have met to review the latest technologies, flight results, and modeling efforts. These meetings have evolved into a biennial international conference that provides the opportunity for the world's spacecraft charging experts and persons new to the discipline to meet and to discuss the latest issues in the field. The thirteenth Spacecraft Charging Technology Conference (SCTC) will be hosted by the California Institute of Technology's Jet Propulsion Laboratory with the support of NASA and the domestic and international spacecraft charging community.Topics of interest to the conference include the following: (1) Charging and arcing testing, (2) Charging and arcing mitigation, (3) Material aging effects, (4) Space Weather: Cause and effect, (5) Charging simulation, (6) Internal charging, (7) On-orbit investigations, (8) Plasma propulsion and tethers, (9) Materials characterization, (10) Electrostatic discharge test standardization, (11) Radiation effects, and (12) Other relevant charging topics.Papers and posters addressing all aspects of charging in the space environment are solicited for the conference. Abstracts for the conference are due by 22 February 2014. The website for registering for the meeting and submitting abstracts is http:// sctc.jpl.nasa.gov. Points News NOAA will host a workshop in Boulder, Colorado, on the comparison and intercalibration of solar energetic particle measurements. It will take place on the afternoon of Friday, 11 April 2014, at the Millennium Harvest House, following the annual Space Weather Workshop. Solar energetic particles (SEPs) consist of ions (protons, helium nuclei, and heavier ions), electrons, and even energetic neutral atoms emitted by the Sun in association with solar flares and coronal mass ejections. Of long-standing scientific interest since the...