E-TBEx A, B (Helio 3)

TBEx [SRI]

The E-TBEx (Enhanced Tandem Beacon Experiment), formerly TBEx (Tandem Beacon Experiment), consists of a tandem pair of 3U CubeSats, each carrying tri-frequency radio beacons, in near-identical, low-inclination orbits, and a cluster of diagnostic sensors on five islands in the Central Pacific sector.

E-TBEx addresses a scientific challenge in 2012 NRC Decadal Survey: Understand how forcing from lower atmosphere acts through plasma-neutral coupling processes to give rise to local, regional, and global-scale structures and dynamics in the atmosphere-ionosphere-magnetosphere system. It monitors the response of bottomside F-layer to wavelike disturbances from below, with sampling intervals less than orbital period, and the development of equatorial plasma structure, including equatorial plasma bubbles (EPBs). The E-TBEx mission is expected to provide a better understanding of the physics that controls the day-to-day variability in development of EPBs (space weather).

It was selected in 2014 by NASA as part of the Science Mission Directorate's Cubesat Initiative. TBEx was selected in 2015 by NASA's CubeSat Launch Initiative (CSLI) to be launched as part of the ELaNa program. Later it was renamed E-TBEx.