The Interstellar Boundary EXplorer (IBEX) mission will observe the boundary between the heliosphere and the interstellar medium from a location near the Earth. The mission will measure the flux of hydrogen Energetic Neutral Atoms (ENAs) which can be directed towards the Sun by an interaction with the heliosheath.
In this visualization, we see the orbit of the spacecraft orbit (green) in relation to the Earth, the orbit of the Moon (gray), and Sun.
For more information, visit the IBEX Mission Project Page at Southwest Research Institute which is managing the mission. We also have additional video outlining the mission (link).
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 184.108.40.206.0