A Naval Research Laboratory (NRL) instrument designed to study the Earth's thermosphere is part of a satellite mission that NASA has selected to move forward into development (Phase B), with launch expected in 2017. The NRL Space Science Division (SSD) developed Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) satellite instrument is part of NASA's Ionospheric Connection Explorer (ICON) mission.
The ICON mission, led by Dr. Thomas Immel at the University of California, Berkeley, will fly a suite of instruments designed to determine the conditions in space modified by weather on the planet, and to understand the way space weather events grow to envelop regions of our planet with dense ionospheric plasma.
Ionospheres act as a boundary between planetary atmospheres and space, containing weakly ionized plasmas that are strongly coupled to their neutral atmospheres, but also influenced by the conditions in the space environment. They experience a constant tug-of-war between these external and internal influences, and exhibit a remarkable set of non-linear behaviors, explains NRL's Dr. Christoph Englert. The unpredictable variability of the Earth's ionosphere interferes with communications and geo-positioning signals and is a national concern. ICON makes a complete set of measurements of the state of the ionosphere and all of the critical drivers that affect it to understand this variability.
NRL's MIGHTI instrument onboard the ICON satellite will contribute to reaching the mission goals by measuring the neutral winds and temperatures in the Earth's low latitude thermosphere. The MIGHTI instrument uses the DASH (Doppler Asymmetric Spatial Heterodyne spectroscopy) technique, which was co-invented and pioneered by NRL. The payload consists of two identical units that will observe the Earth's thermosphere with perpendicular viewing directions. As ICON travels eastward and continuously images the thermosphere and ionosphere, MIGHTI will measure the vector components of the vertical wind profile.
NRL's MIGHTI is named for Albert Michelson, a physicist known for his research on the measurement of the speed of light using a related interferometer type. More directly, MIGHTI builds on technology previously used in NRL's SHIMMER (Spatial Heterodyne Imager for Mesospheric Radicals), a payload aboard STPSat-1. The NRL MIGHTI team is led by Dr. Christoph Englert, head of the Geospace Science and Technology Branch in NRL's Space Science Division.
In addition to SSD leading the MIGHTI instrument, NRL scientists Dr. Joe Huba from the Plasma Physics Division and Dr. Andrew Stephan from the SSD will provide ICON scientific data analysis and interpretation.
ICON is part of NASA's Heliophysics Explorer Program. The Explorer program, which has launched more than 90 missions since 1958, is managed by NASA's Goddard Space Flight Center for the Science Mission Directorate.