Proposal cover

The Integrated Solar Probe Imaging Suite (ISIS) is a sophisticated remote sensing package to provide revolutionary new science on one of the most exciting adventures in the solar system. Highly leveraged with strong European collaboration, the ISIS investigation addresses all of the primary and applicable secondary scientific objectives stated in the AO, within the stringent fiscal constraints of the Solar Probe Mission. Success ultimately depends on linking the remote sensing and in-situ observations to understand the relationship between the local plasma environment, its magnetic source, and the widely varying global structure. The ISIS team ensures this success with outstanding, world-class analysis and modeling expertise. Together with the selected in-situ team, the ISIS team will unveil the mysteries of the Sun's polar cap and the source regions of the solar wind, maximizing scientific benefit and community involvement in this unprecedented exploration of our star.

The ISIS instrument package consists of an EUV Disk Imager (EUVI), a Magnetographic Imager (MI) and Polar Oscillations Imager (POI), a Hemispheric Imager (HI), and a High Resolution Coronal Imager (HRCI). EUVI maximizes scientific value in its simplicity and high sensitivity without compromising temperature coverage. By imaging small scale dynamics at the base of the corona over the temperature range 10³ K to 10⁷ K along a continuous ``ground track'' under the spacecraft, EUVI will observe the source regions of energy release on all scales, and provide crucial context for the in-situ package. MI will probe the previously unseen overall magnetic structure of the Sun's poles, examine the morphology of the finest scale magnetic structures, and provide a high resolution magnetic ``ground track'' similar to EUVI. POI will record a single helioseismic data set over each pole during both solar maximum and solar minimum to explore polar subsurface flows, the mysteries of the solar dynamo, and the origins of the solar cycle. HI will provide full hemispheric field-of-view imaging of the corona as the Solar Probe spacecraft flies through it, maximizing contrast in faint coronal features by observing directly along magnetic flux tubes and enabling true 3-D tomography to resolve critical ambiguities in the in-situ data. HRCI will provide ultra-high resolution imaging along the spacecraft trajectory to study never-before-seen microscale coronal structures, identify coronal effects of reconnection, and track Alfvén waves and other forms of energy into the solar wind.

The ISIS instrument team, led by Southwest Research Institute (SwRI), has extensive experience designing, building and flying space instrumentation, including many of the instruments on SOHO (SUMER, LASCO, EIT, GOLF), TRACE, Cassini/CAPS, and most recently the IMAGE Midex mission. Moreover, the ISIS team maximizes NASA resources with highly leveraged hardware, data analysis, and science contributions from our French and German partners of roughly 1/3 the total investigation cost, or $16 million. Together, the ISIS team provides a significantly enhanced and sophisticated scientific investigation.