Measuring the plasma environment at Mercury: The fast imaging plasma spectrometer

Abstract

Abstract-The plasma environment at Mercury is a rich laboratory for studying the interaction ofthe solar wind with a planet. Three primary populations of ions exist at Mercury: solar wind, magnetospheric, and pickup ions. These pickup ions are generated through the ionization ofMercury's exosphere or are sputtered particles from the Mercury surface. A comprehensive mission to Mercury, such as MESSENGER (MErcury: Surface, Space ENvironment, GEochemistry, Ranging), should include a sensor that is able to determine the dynamical properties and composition of all these plasma components. An instrument to measure the composition of these ion populations and their three-dimensional velocity distribution functions must be lightweight, fast, and have a very large field of view.The fast imaging plasma spectrometer (FIPS) is an imaging mass spectrometer, part of NASA's MESSENGER mission, the first Mercury orbiter. This versatile instrument has a very small footprint, and has a mass that is ' """' 1 order of magnitude less than other comparable systems. It maintains a nearly full-hemisphere field of view, suitable for either spinning or three-axis-stabilized platforms, The major piece of innovation to enable this sensor is a new deflection system geometry that enables a large instantaneous (' """' 1.5n) field ofview. This novel electrostatic analyzer system is then combined with a position sensitive time-of-flight system. We discuss the design and prototype tests ofthe FIPS deflection system and show how this system is expected to address one key problem in Mercury science, that of the nature of the radar-bright regions at the Hennean poles.

A Systematic Review of Product Design for Space Instrument Innovation, Reliability, and Manufacturing

“…The Key Considerations in Space Koehn [41] Discuss the design and prototype tests of the fast-imaging plasma spectrometer (FIPS) deflection system Lightweight, fast, and have a very large field of view Koga [42] Discuss the results of the engineering model (EM) and its properties Particle and plasma Krebs [43] Develop the mercury laser altimeter Space-flight environmental tests Lepri [44] Discuss an adaptation of the fast-imaging plasma spectrometer (FIPS) for the measurement of negatively charged particles. Design modification LIFE [45] Developed an automated, miniaturized, integrated fluidic system for in-situ measurements of gene expression in microbial samples…”

“…Koehn et al [41] discussed the design and prototype tests of the fast-imaging plasma spectrometer (FIPS) deflection system. The major piece of innovation is to improve the instrument to enable a larger instantaneous field of view.…”

Pickup ion processes associated with spacecraft thrusters: Implications for solar probe plus

“…A difference between the Hermean magnetosphere and the terrestrial one is that, due to the relative small size of the magnetosphere at Mercury, the region where charged particle populations might be expected to be trapped is so small that any such populations would be transient. A consequence of this is that where usually the planetary atmosphere is an important source of ions, at Mercury the magnetosphere couples directly to the planet's surface which causes the surface to act as both a sink for ions and also a source as ions are sputtered away [Koehn et al, 2002]. These pickup ions, especially the sodium ions, tend to have gyro-radii within an order of the size of the Hermean magnetosphere and therefore kinetic effects become important [Gingell et al, 2015, Trávnícek et al, 2010.…”

“…Pickup ion activity can also be seen closer to home in such places as the Earth's bow shock and magnetosphere [Mall et al, 1998, Sadovski and Skalsky, 2014, Zhang et al, 2001 and also those of other planets such as Mars , Cravens et al, 2002, Wei and Russell, 2006 and Mercury [Baumjohann et al, 2006, Koehn et al, 2002, Sarantos et al, 2009 although to a lesser extent. Additionally certain moons in the solar system can be sources of pickup ions such as Io at Jupiter [Blanco-Cano et al, 2001, Russell et al, 1998] and Enceladus at Saturn [Sittler et al, 2004, Tokar et al, 2008, Tseng et al, 2008.…”

A highly miniaturized electron and ion energy spectrometer prototype for the rapid analysis of space plasmas

“…Many miniaturized versions of these sensors have been produced by various groups, sometimes by using novel new electrode arrangements 10 , often by scaling down conventional designs 11 and also by combining functions (e.g. electron and ion measuring) into smaller packages 12 .…”