Topic
Solar Sentinels
About: Solar Sentinels is a research topic. Over the lifetime, 6 publications have been published within this topic receiving 122 citations.
Papers
TL;DR: In this paper, the authors studied the effect of the largest halo coronal mass ejection (CME) since the Halloween storm in 2003, which occurred on 2006 December 13, in terms of its solar source and heliospheric consequences, and revealed a technique that combines MHD propagation of the solar wind and type II emissions to predict the shock arrival time at the Earth.
Abstract: The biggest halo coronal mass ejection (CME) since the Halloween storm in 2003, which occurred on 2006 December 13, is studied in terms of its solar source and heliospheric consequences. The CME was accompanied by an X3.4 flare, EUV dimmings, and coronal waves. It generated significant space weather effects such as an interplanetary shock, radio bursts, major solar energetic particle (SEP) events, and a magnetic cloud (MC) that were detected by a fleet of spacecraft including STEREO, ACE, WIND, and Ulysses. Reconstruction of the MC with the Grad-Shafranov (GS) method yields an axis orientation oblique to the flare ribbons. Observations of the SEP intensities and anisotropies show that the particles can be trapped, deflected, and reaccelerated by the large-scale transient structures. The CME-driven shock was observed at both the Earth and Ulysses when they were separated by 74 degrees in latitude and 117 degrees in longitude, which is the largest shock extent ever detected. The ejecta seem to have been missed at Ulysses. The shock arrival time at Ulysses is well predicted by an MHD model that can propagate the 1 AU data outward. The CME/shock is tracked remarkably well from the Sun all the way to Ulysses by coronagraph images, type II frequency drift, in situ measurements, and the MHD model. These results reveal a technique that combines MHD propagation of the solar wind and type II emissions to predict the shock arrival time at the Earth, which is a significant advance for space weather forecasting, especially when in situ data become available from the Solar Orbiter and Solar Sentinels.
125 citations
24 Aug 2019
TL;DR: In this article, the authors proposed the Solar Sentinels mission, which aims to discover, understand, and model the heliospheric initiation, propagation, and solar connection of those energetic phenomena that adversely affect space exploration and life and society here on Earth.
Abstract: The goal of NASA s Living With a Star (LWS) program is to develop the scientific understanding necessary to effectively address those aspects of the connected Sun Earth system that directly affect life and society. Along with the other elements of LWS, Solar Sentinels aims to discover, understand, and model the heliospheric initiation, propagation, and solar connection of those energetic phenomena that adversely affect space exploration and life and society here on Earth. The Solar Sentinels mission will address the following questions: (1) How, where, and under what circumstances are solar energetic particles (SEPs) accelerated to high energies and how do they propagate through the heliosphere? And (2) How are solar wind structures associated with these SEPs, like CMEs, shocks, and high-speed streams, initiated, propagate, evolve, and interact in the inner heliosphere? The Sentinels STDT recommends implementing this mission in two portions, one optimized for inner heliospheric in-situ measurements and the other for solar remote observations. Sentinels will greatly enhance the overall LWS science return.
5 citations
18 Sep 2007
TL;DR: The MESSENGER (MErcury Surface, Space ENvironment, Geochemistry, and Ranging) spacecraft, designed, built, and tested by The Johns Hopkins University Applied Physics Laboratory, was launched on August 2, 2004, on a mission to orbit the planet Mercury for one year.
Abstract: Spacecraft missions to the inner solar system require specialized thermal protection and designs to withstand the intense heat associated with proximity to the Sun. The MESSENGER (MErcury Surface, Space ENvironment, Geochemistry, and Ranging) spacecraft, designed, built, and tested by The Johns Hopkins University Applied Physics Laboratory, was launched on August 2, 2004, on a mission to orbit the planet Mercury for one year. High-temperature technology and specialized thermal designs were developed for MESSENGER’s telecommunications, power, guidance and control, and thermal control subsystems. MESSENGER milestones in these as areas may be applicable to such future missions as Solar Sentinels, Solar Orbiter, and BepiColombo.
3 citations
1 Jan 2002
1 citations
TL;DR: In this article, a top-hat type symmetric quadrispheric analyzer with a pair of electrostatic deflector plates designed to accept approximately ± 40° in elevation is presented.
Abstract: In-situ instrumentation for proposed future solar and heliophysics missions close to the sun, e.g., ESA's Solar Orbiter
and NASA's Solar Sentinels, have challenging requirements. Notably, the two major challenges are the large dynamic
range required to be covered and the mission lifetime. For example, the proposed orbit of Solar Orbiter ranges from 0.22
AU to 1.39 AU, resulting in up to 2 orders of magnitude change in flux that the instrument is required to handle, with a
proposed mission life of greater than 10 years. We present details of a prototype instrument that is currently being
developed to address some of these challenges. The instrument is a conventional "top-hat" type symmetric quadrispheric
analyzer with a pair of electrostatic deflector plates designed to accept approximately ± 40° in elevation. Optimization of
the geometry of the deflector plates will be discussed and preliminary results of the performance of the instrument will
be presented. In addition, some of the other techniques and strategies that will be required to deliver the necessary
performance will also be discussed.
Performance Metrics
| Year | Papers |
|---|---|
| 2019 | 1 |
| 2008 | 2 |
| 2007 | 2 |
| 2002 | 1 |